By Ben Carpenter
My Personal Takeaways →Ben Carpenter breaks fat loss down with a behavior-first, evidence-based approach that avoids fad diet noise. The key ideas focus on food environment, portions, consistency, and sustainable habits over perfection or willpower myths.
By Ben Carpenter
If you don’t know what your destination is, how can you decide which way to aim? •Do you want to lose fat because you want to change the way you look or change the way you feel? •What habits are you willing to adopt to get there? •Are those habits going to be sustainable for you? •Are they going to improve your overall quality of life?
If getting leaner was a sure fire way to improve how you feel about yourself, you would expect those who push this endeavor to the limit to be the happiest people around, but that isn’t likely to be the case.
One review paper concluded that male and female bodybuilders experience high levels of muscle dysmorphia, associated with anxiety, depression, neuroticism and perfectionism, and negatively associated with self esteem.
Your happiness is not guaranteed to go up when your body fat levels go down, and obsessing over the way you look can come with its own psychological risks.
It is possible to spend your entire life trying to change your body only to find you never reached that elusive point of happiness. I am not deterring you if your goal is fat loss, just making sure you aren’t chasing the wrong thing.
Some people could progress in their career path much faster than you with the same level of effort. Perhaps they inherited a more fortunate starting position, like being able to afford the best private education or having a parent that owns the company you both work for. Yes, both of you need to work hard to reach the top of the career ladder, but if they find it easier than you do, it doesn’t necessarily mean that they just ‘wanted it more’. Likewise, some people will go through life without ever feeling like they struggle to manage their weight and it doesn’t automatically indicate that they have an inherent level of superior willpower.
Body weights are trending upwards. It has been estimated that the global prevalence of obesity has almost tripled since 1975.
One of the largest contributors is thought to be our changing food environment. We have a rapidly increasing availability of high calorie, ultra processed foods that make us more likely to eat.
A medium sized apple has somewhere in the ballpark of 100 calories and a single doughnut can contain anything up to a few hundred calories. Which one do you think is easier to consume in large quantities?
In one study, participants were given the option of eating from a bowl of apple slices or a bowl of popcorn. There were three conditions to this experiment. 1. Apple slices were placed near the participant (within arm’s reach) and popcorn was placed two meters away. 2. Popcorn was placed within arm’s reach and the apple slices were placed two meters away. 3. Both the popcorn and the apple slices were placed within arm’s reach. The participants were sat in a room and told by one of the researchers, ‘I will be right back with some questionnaires. By the way, there are foods in the bowls if you would like something to eat.’ This was to make sure that they consumed whatever foods they wanted without being influenced. As it turns out, they were inclined to eat more of whichever food was closest to them, even though they considered popcorn as the tastier of the two options.
Another study gave participants the same bowl of M&Ms but simply placed it next to them or on the other side of the table. It found that by placing the bowl 20cm away instead of 70cm away, more people were encouraged to eat them. This can be translated to the food choices we make every day too: multiple research studies suggest that people who live in closer proximity to a higher number of fast food outlets are at greater risk of having heavier body weights than those who don’t.
The easier it is to eat something, the more likely it is that someone will eat it.
Knowing this, you can actually use it to your advantage by making preferred options more convenient. It has been shown that if you serve boring healthier foods like vegetables in isolation you are more inclined to eat them than when they are competing with more delicious options.
This kind of concept is known as the ‘cafeteria’ diet; if you give rodents a wide selection of stereotypically unhealthy, highly palatable foods and let them eat as much as they want, it is a reliable method of promoting weight gain. This effect has also been shown in humans. If you give people free access to a lot of tasty food, it is very likely that they will naturally eat more and gain weight. A mechanism that could explain this revolves around something called ‘sensory specific satiety’, which essentially means the feeling of fullness is food specific. In the same way you might stop eating your main course when you feel full but still somehow have room for dessert, it is possible that one of the reasons some people simply stop eating is because they are tired of eating the same food. Eating a lot of one food may induce taste fatigue, but if you have lots of delicious foods available in front of you it is easier to keep going. This has been tested in research studies. One paper gave participants sandwiches to eat with either the same filling repeatedly or with four different fillings. When served four different fillings, they ate approximately one third more food.
Multiple research trials have confirmed that when larger portions are offered, people tend to consume more food.
For example, one study had participants eating in a lab once per week for four weeks. On each occasion, they were served a different sized sandwich, 6, 8, 10 or 12 inches. Each time, they were told they could eat as much or as little as they wanted. Both males and females rated the 6 inch sandwich as being close to their usual portion, yet when given larger sandwiches their calorie intake went up. When served the 12 inch sandwich, males consumed 56 percent and females consumed 31 percent more calories than when they were served the 6 inch sandwich. On top of that, despite the higher calorie intake, ratings of hunger and fullness were not significantly different, suggesting that participants ‘were able to override or adjust their level of hunger and satiety to accommodate greater energy intakes’. Discrete portion size manipulation can encourage you to eat more food without you realizing it and without even making you feel fuller afterwards.
This is the thing: most research in this area not only suggests that exerting weight stigma doesn’t help, but that it is directly harmful. Rather than making someone want to exercise more, people who have experienced weight stigma are more likely to want to avoid exercise than participate in it. Therefore, those people who make fat jokes at their friend’s expense are probably making them feel less inclined to work out rather than exerting some form of positive influence.
In one study, participants read either an article called ‘Quit Smoking or Lose Your Job’ or one called ‘Lose Weight or Lose Your Job’ to test whether reading articles about weight discrimination would impact how they felt afterwards. After reading these articles, they were left alone in a room with some snack bowls, entirely unaware of the true purpose of the study. Contrary to what some people may think, participants who perceived themselves as overweight actually consumed more calories and felt less capable of controlling their weight after reading a weight stigmatizing article.
It was only through real life interactions with my clients that I learned that rather than simply telling people to eat less food, pausing to question what motivates them to eat more in the first place can be very valuable.
Many people respond to life stresses by ‘comfort eating’. In one study, 73 percent of participants reported an increase in snacking behavior when stressed. On top of that, it found that they were more inclined to eat foods like chocolate, sweets, cakes and biscuits and less inclined to eat foods like meat, fish, fruit and vegetables.
To assess whether anxiety impacts food intake, one study took a small group of 12 people who were scheduled for hernia surgery and measured how much food they ate at lunch the day before surgery and again one month later. On average, the anxiety prior to surgery didn’t seem to influence the group’s food intake; however, the study noted that some participants responded in completely opposite directions, with four men increasing what they ate by 25 percent on the day before surgery and two men eating over 25 percent less. The paper proposed the idea that some people are ‘stress eaters’ and some people are ‘stress fasters’.
Of course, stress is not the only emotion that can impact eating behavior. Many people will be familiar with eating when bored. One research study hypothesized that there may be a link between boredom and obesity so it tested whether participants consumed more food while doing a boring task versus an interesting one. The research assistant left the room for each task but casually said to the participants on the way out, ‘Feel free to help yourself to some crackers if you would like,’ while emptying a fresh bag into a bowl. When participants were following the boring task, they ate more. The paper suggested that, ‘It may be helpful for dieters, regardless of their weight, to remove food from areas where boredom regularly occurs.’
One three part study asked participants to fill out a food diary for a week, along with short questionnaires relating to mood. It not only found that boredom was associated with higher calorie intakes but feeling bored promoted the desire to snack on unhealthier food options specifically.
A meta analysis of 33 different studies concluded that there is a causal role between negative emotions and greater food intake, especially in restrained eaters and binge eaters. This helps highlight something that I believe very strongly: we can consider our emotional state as a driving force behind how much food we eat as well as the types of food we lean towards eating.
It is proposed that depression and obesity have a significant bidirectional relationship, essentially meaning that having obesity can increase the risk of depression but depression itself can also predict the likelihood of developing obesity.
So yes, weight loss boils down to calories in versus calories out, but there are a multitude of factors that influence how easy that is for someone to achieve and we must be cognizant of that so we keep our expectations realistic and develop strategies to overcome these hurdles where necessary.
As you lose weight, your body will start to burn less energy because a lighter version of you requires less energy than a heavier version of you.
If you require approximately 2,500 calories per day to maintain your body weight and you reduce this so you are eating 2,000 calories every day, you will start off in a 500 calorie deficit and lose weight. However, as your body weight decreases, so does the number of calories you burn. The number of calories you burn through movement will decrease, both via exercise as well as non exercise activity thermogenesis. Also, because you are consuming smaller quantities of food, the number of calories you burn via TEF will decrease. At some point, 2,000 calories per day may no longer be a deficit to your smaller body size and your weight loss could plateau.
If there is only one thing you remember from this, let it be: when you change how many calories you consume, you will also change the number of calories you expend, which makes the speed you gain weight or lose weight somewhat unpredictable.
Protein is a major component of every cell in your body. In the dietary world, protein receives the most attention for growth and repair. The amount you are recommended to consume daily, referred to as the ‘recommended dietary allowance’ (RDA) is 0.8 grams per kilogram of body weight.
As stated earlier, protein is believed to have the highest thermic effect (20 30 percent) followed by carbohydrates (5 10 percent) and then fat (0 3 percent). This means that on a calorie for calorie basis, your body will burn more energy when you consume protein than either carbohydrate or fat. Due to this, it is believed that high protein diets may offer a weight loss advantage over lower protein diets. But it is worth keeping in mind that this accounts for a pretty low number of calories burned, so tweaking the macronutrient composition of your diet to try to keep your metabolic rate as high as possible isn’t likely to lead to groundbreaking results. If you increase your protein intake a smidge, the number of additional calories you will burn is a little bit like getting a few extra miles out of your car’s fuel tank, you just aren’t really going to notice it. If you compared the thermic effect of a diet of pure dietary fat to pure dietary protein, the number of calories burned between the two would be more of a contrast. But when someone nudges their protein intake up a little bit strictly for the purpose of burning more calories, the difference is probably too small for anyone to notice, at least in the short term, although it may pan out to some additional weight loss in the long term.
One research paper tested what would happen if participants ate two different kinds of sandwich. The ‘whole food’ sandwich was made with deli cheese and multigrain bread. The ‘processed food’ sandwich was made with cheese slices and white bread. This study measured postprandial energy expenditure which, in simple terms, is a fancy way of saying the number of calories your body burns after a meal. It found that the processed sandwich made with white bread and those weirdly vibrantly colored cheese slices resulted in 50 percent less energy burned after eating. This study didn’t measure body composition changes over time, but if you eat an entirely processed diet and burn 50 percent fewer calories after every single meal that might add up to something noticeable in the long term.
This study didn’t tell us if someone consuming a diet high in ultra processed foods would gain weight but it did at least show us a plausible mechanism for why ultra processed foods could be more fattening on a calorie for calorie basis.
One study created something called the ‘satiety index’, where researchers gave people the same 240 calorie portion of 38 different foods, recorded how hungry they felt every 15 minutes afterwards and after two hours, let them eat from a food buffet. The idea here was if the initial 240 calorie portion of food wasn’t very filling, they would eat a lot at the subsequent buffet. By doing this with a wide selection of different items, you can see trends, like which food groups are most likely to fill you up, and which aren’t.
Foods that were the most filling tended to be ones that were high in protein, fibre and water, as well as those that had a higher serving weight. Foods that had a high fat content and had a high palatability score tended to have lower satiety index ratings. Basically, foods that were calorie dense and delicious tended to score worse, with croissants, cake and doughnuts taking the three bottom spots. All three of these are ultra processed, have a high fat content, a small serving size for the 240 calorie portion and taste incredible (obviously taste is subjective). The foods that were most satiating were plain boiled potatoes, ling fish (a white fish, like cod) and porridge, all of which have a minimal amount of processing and a much larger serving size for the same number of calories. This concept is referred to as ‘energy density’.
One of the theories behind why low energy density foods are good for weight management purposes is that your hunger signals are influenced by the weight and volume of what you are eating, so large platefuls of food that fill more space in your stomach may be more satiating than small platefuls of food even when the calorie content and the type of foods are the same. As an obscure example of this, one study gave participants two versions of cheese puffs that differed by how much they were aerated. Because one version of those brightly colored cheesy snacks contained more air each one was bigger, despite the fact its calorie content did not change. Although participants were allowed to eat as many of them as they would like, they naturally ate fewer of the snacks that contained more air, meaning their calorie intake was lower. Despite ingesting fewer calories, participants did not feel hungrier, implying that manipulating food volume can nudge people towards eating less energy without necessarily impacting their appetite, which could be very beneficial. Other research has tested this hypothesis by serving people yogurt based milkshakes with different amounts of air shortly before lunch; it was shown that the highest volume option reduced how much food they ate afterwards.
In a series of different test conditions, it was shown that if you increase the ratio of vegetables in a mixed meal also containing meat and grains, people tend to eat less food overall. If you have a plateful of food which contains beef, rice and broccoli, simply adding more of the broccoli probably won’t influence how many calories you eat, but if broccoli takes up a larger percentage of the plate by substituting some of the beef and the rice it may nudge you towards eating fewer calories without you feeling hungrier.
This effect has also been shown in children. For example, if you make a pasta with additional tomatoes, broccoli, cauliflower, zucchini or squash hidden inside it, kids may still eat the same amount of green beans that are served on the side, meaning the veggies chopped up finely and incorporated into their main course are additional and don’t come at the expense of any served next to it.
The point I really want to drive home is that although being in a calorie deficit is mandatory for weight loss and in some ways food quality is irrelevant to that fact, it is also true that we have a massive amount of research showing how different food attributes help regulate your appetite, so food quality absolutely is important as well. Prioritizing unprocessed foods with a low energy density is a very well studied strategy to keep your hunger levels in check during periods of reduced calorie dieting.
One interesting observation from this study was that participants ate the ultra processed foods approximately 50 percent faster than unprocessed foods in terms of calories consumed per minute. A follow up study compared the eating rate of unprocessed, processed and ultra processed foods and again found that the more processed a food is, the faster people tend to eat it. This is worth noting because faster eating rates have been shown across a wide range of studies to promote higher energy intakes. Perhaps we have a tendency to chow down ultra processed foods much faster, which inadvertently allows us to eat more food before our satiety signals eventually tell us that we are full.
A good diet that you can follow consistently will be better than a perfect diet that you can’t stick with because it is too strict. Your goal is to find a balance that works for you.
If you consistently consumed more fruit and vegetables, fewer ultra processed foods, less alcohol and consistently hit your physical activity goals, you know you are implementing some identifiable behavioral steps that can improve your health, even if you aren’t setting ambitious weight loss goals.
A review paper pooled together 29 studies which looked at weight loss maintenance rates and concluded that participants who started with more aggressive calorie deficits (therefore resulting in rapid initial weight loss) actually maintained more weight loss in the long term.
The researchers proposed that fast weight loss may actually be more motivating for some people, as they noticed participants in that group ramped up their physical activity levels, whereas those in the slow dieting group did not. This suggests that people may prefer instant gratification and that seeing the number on the scales going down is a reward for their work, which may encourage them to stick with the plan. The researchers also pointed out that dietary prescription for rapid weight loss is sometimes simpler, in this instance, participants were given commercially prepared meal replacements, as it takes the guesswork out of knowing what to do. Sometimes, giving people really simple advice to follow works better, even if the intervention seems much more extreme.
The researchers conducting this study suggest that if you want to maximize your muscle mass, strength and overall performance, dieting slowly is the preferred option. So, if you want to keep making progress in the gym, a gentler reduction in calories will work better, but it will take longer. Some of you, though, might prefer to just rip the band aid off quickly, diet more aggressively and know that you aren’t likely to set any personal bests during the weight loss phase.
That’s right, at the end of the trial, everything was basically the same between groups: body composition, hunger, appetite hormones and resting metabolic rate. As neither fast nor slow weight loss emerged as conclusively better than the other, the authors proposed that people could pick whatever dieting speed is easier for them to stick with, because it probably doesn’t matter much. The best way to summarize all this information is to turn to a meta analysis that pools multiple studies together to try to give us an overall conclusion. One review paper included seven controlled trials and concluded that although there was a lack of good quality long term studies, slower rates of weight loss appeared to be slightly better for fat loss and preservation of metabolic rate.
Solely from a health perspective, being physically inactive is associated with an increased risk of conditions like cardiovascular disease and type 2 diabetes as well as all cause mortality. Therefore, we shouldn’t be surprised that the potential health benefits of exercise are vast and diverse, including decreased risk of all cause mortality and decreased risk of over 25 chronic medical conditions, including cardiovascular disease, type 2 diabetes, ischemic heart disease and hypertension as well as slowing down the decline of health and functioning associated with age.
If you perform resistance training with multiple exercises and short rest periods in between them, it can feel increasingly similar to aerobic training. Similarly, if you crank up the intensity of your aerobic training really high, like sprinting at maximal effort for a short period of time, it starts to more closely resemble the energy systems used during resistance training.
Importantly, although there are general exercise recommendations, like aiming for at least 150 300 minutes of moderate intensity or 75 150 minutes of vigorous intensity exercise per week, you do not necessarily have to hit that target to improve your health.
Even walking more is associated with a reduced mortality risk, so just doing that would be a great start for lots of people.
From a body composition perspective, exercise is always going to play a role in weight management because, of course, moving more means we are also burning more energy, nudging us towards a calorie deficit (consuming fewer calories than we burn). That being said, it actually isn’t a reliably powerful stimulus for losing weight in isolation.
It is much easier to consume those calories from food than it is to burn them via exercise. You could grab a chocolate bar, energy drink or even a fruit smoothie from the gym on the way out and the energy content may be higher than the amount you expended during your workout. This is why even aerobic training, the common exercise of choice for fat loss, often delivers underwhelming weight loss results in isolation and needs to be paired with dietary changes.
In an ideal world, a great goal would be to have an exercise routine that involves both aerobic and resistance training, like aiming for at least 150 minutes of moderate cardiovascular exercise per week plus at least a couple of resistance training workouts.
One meta analysis pooled together dozens of research studies that all compared different training intensities and guess what it found? From a fat loss perspective, it doesn’t actually seem to matter much at all.
Practically, there are reasons you may prefer one type of training to another. For example, if you are short on time, you may prefer cranking out some higher intensity work because it is more time efficient, or perhaps you just enjoy training harder and faster. Alternatively, if you are brand new to exercise you may prefer easing yourself in gently to allow yourself to feel more comfortable working out before you decide to see how your body feels when you push it harder. From a body composition perspective, it isn’t a make or break situation, so it makes sense to do whatever you prefer, as finding a form of exercise you enjoy enough to actually stick with is far more important.
At the end of the trial, there were no significant differences between the groups, discrediting the idea that fasted cardio is a shortcut to faster fat loss. Other research has come to the same conclusion.
Long story short, based on the limited research that is available now, there is no really strong evidence that training fasted will have a pronounced fat loss effect compared with eating before working out, so it is a sensible idea to pick based on personal preference.
You may notice a bit of a theme emerging, some things that sound super exciting on paper probably aren’t worth stressing about, in my opinion. That is not to say that none of these make any difference at all, it is simply that the difference they make is probably small enough that most people shouldn’t panic over whether they do them or not.
There is one basic principle though that I would be remiss not to discuss and that is a concept known as ‘progressive overload’. Although it is not necessarily specific to fat loss (which we know can be achieved even without exercise) it can play an integral role in maintaining or increasing lean body mass, which is a sensible idea when dieting. Progressive overload means giving your body additional stimulus to adapt to, which basically means just doing more over time.
In fact, if I could pick any fitness advice to announce over a megaphone to the world, it would simply be to find a form of exercise you enjoy enough to actually stick with and then try to improve on it over time.
From a weight loss perspective, consider dietary changes as your main course and exercise more like a side dish.
What looks best on paper is irrelevant if you hate it and don’t stick to it in the long run.
To make things more enjoyable, try and play to your own psychology. Do you prefer working out alone or with someone else? Do you feel more motivated if you track your workouts so you can see what progress you have made? Do you prefer working out in the morning before work, or squeezing in a short workout on your lunch break? Do you prefer being outside or inside? Do you prefer lifting weights or doing body weight exercises? There are many variables you can choose to suit your circumstances and preferences.
Here is the secret that most weight loss books rarely discuss: while short term weight loss is relatively simple, long term weight loss success rates are notoriously low. Although it is a well established fact in the research literature, people don’t like talking about it because it removes some of the magic of whatever diet they are twisting your arm into believing will change your life.
One of the biggest differences here was that it was a ‘multidisciplinary’ approach, which not only prescribed a low calorie diet, but also physical activity, nutritional education and cognitive behavioral techniques based around issues like self control and relapse prevention. On top of that, participants revisited the hospital for one day every four months for motivational purposes, saw a psychologist for a minimum of ten sessions and received regular diet reviews. All of which seems to have worked for nearly half of participants. But what about the rest? What were the reasons that some people regained the lost weight, even while on this comprehensive plan? One of the main culprits was overeating outside of hunger, such as loneliness, depression and anxiety, all of which can be potent influences on the desire to eat, as we have talked about in the section on emotional eating. Perhaps individuals who eat in response to negative emotions may be better suited focusing on emotional regulation skills rather than simply being prescribed a low calorie diet.
Here are some examples of what was included:
One of the reasons people tend to put weight back on after dieting for a while is they don’t realize they need to adjust their food intake over time. If you reduce your calorie intake a little bit and increase your physical activity a little bit you will lose some weight, but at some point your body won’t need as many calories per day as it did when it was at a higher weight and you will therefore no longer be in a calorie deficit. Hitting weight loss plateaus is not only normal but pretty much inevitable; however, many people become discouraged and revert to what they were doing before they embarked on their diet. They jump off the metaphorical diet wagon when it seems like it isn’t working anymore.
On the other hand, if you find a form of physical activity that you actually enjoy and want to keep repeating, it is suddenly a different psychology completely. Some people love walking because it is much needed time to themselves when they can listen to music or put on an audiobook. Other people enjoy jogging with a friend because it gives them an excuse to socialize at the same time, or weightlifting because they like the feeling of getting stronger, or boxing because it feels nice to let off some steam after a stressful day at work. Nutrition wise, you are going to want to find a balance between any healthy behaviors you are adopting and sustainability, because diets that suck all the joy out of your life just aren’t going to work in the long run. Many people can stick to strict diets when there is deep motivation, like vegan diets for ethical reasons or halal diets for religious reasons. Contrast that with those who impose overly restrictive dietary plans upon themselves that they hate simply because they want to lose some body fat and you can see why so many people feel like they ‘fall off the wagon’.
If we look at the smaller minority of people who maintain a significant degree of weight loss, there are some behaviors that lots of them seem to have in common, so we can use these as some best practices to maximize your chances of success. These include eating a reduced calorie diet (obviously) and often a reduced fat diet, likely because of its low energy density properties, increased consumption of fruits and vegetables, high levels of physical activity, and regular self monitoring of body weight and often food intake.
Although they are harder to measure, some psychological components are a very good idea for you to be aware of, like the importance of motivation, goal setting and prioritizing enjoyment. Some studies also discuss ‘relapse prevention’ strategies, like addressing emotional eating.
You can lose 1 pound of body fat and gain 1 pound of lean body mass and the number on the scales would not change, even if your body composition has. This is why ‘losing weight’ and ‘losing fat’ are not technically the same thing, even though they do often happen in tandem.
The act of counting calories is separate to whether calories matter. Think of it like this: one person may save money by tracking everything they earn and everything they spend, and another person may save money simply by deciding not to spend money on certain items. One person counted and the other person didn’t, but the underlying result was still the same: they spent less money than they earned.
As a single example of this, a review paper looked at answering the age old question of which weight loss diet was superior, examining the results from 48 different controlled studies involving a total of 7,286 individuals. This comprehensive review included studies that had looked at the following diets: Atkins, South Beach, Zone, Jenny Craig, Nutrisystem, LEARN, Volumetrics, The Biggest Loser Club, Weight Watchers, Ornish and Rosemary Conley. Do you know which of them came out as clearly superior? None of them. The differences between them were too small for any of them to be considered a real winner.
This is one of the reasons high protein diets are often recommended because they appear to have a slight weight loss advantage. For example, one meta analysis comparing high protein to moderate protein diets found that high protein diets resulted in a little bit more weight loss, even when the number of calories were the same.
From a body composition perspective, high protein diets win. That is the simplified message here.
The most concise answer I can give is that when someone is resistance training and isn’t dieting, 1.6 grams per kilogram per day appears to be sufficient for muscle building purposes; intakes above and beyond that don’t appear to offer much additional advantage. Some research in competitive bodybuilders propose intakes as high as 2.2 grams per kilogram day. This basically shows us where the ceiling is for people who have the highest protein demands.
One theory behind reduced fat diets is that because fat is the most calorie dense macronutrient, aiming for a low fat intake would be the best way to reduce the overall energy content of your diet. This idea is not without merit. Some studies have shown that if you covertly reduce the fat content of people’s diets, it nudges them towards eating fewer calories.
Is avoiding carbohydrates the key to unlocking the mysterious fat loss strategy that so many people yearn for? Well, there actually is a lot of research showing that low carb diets do achieve a greater degree of weight loss than low fat diets. There is so much research in fact that there are meta analysis papers that pool studies together and conclude the same thing. For example, in one meta analysis of 11 different studies, low carb diets resulted in more weight loss at the six month mark than low fat diets and another meta analysis showed very low carbohydrate diets resulted in greater weight loss than low fat diets at the 12 month mark.
To answer this question, one study utilized four different diet conditions, rather than just two. The groups were divided as follows:
From all this, we can conclude that low carb diets win for weight loss, especially in the early stages, but for actual fat loss, it looks like a draw. Therefore, it makes sense to choose based on personal preference. If you naturally gravitate towards high carb foods, a low carb diet might be a disaster for you, and vice versa. Consider what foods you enjoy and how you feel when you’re following that nutritional approach.
If you want to maximize fat loss and lean body mass preservation, consuming adequate protein is a well agreed upon recommendation. Once that is in place, the remaining ratio of carbohydrates to dietary fats can be based on your own personal preference.
‘Alternate day fasting did not produce superior adherence, weight loss, weight maintenance, or cardioprotection versus daily calorie restriction.’
They concluded that there was no evidence of any health effects that were specific to fasting, and fasting itself was worse for fat loss and lean body mass preservation.
If we look at review papers that pool multiple studies together, we can see which way the research points. Many reviews have arrived at similar conclusions: intermittent fasting is a viable strategy for weight loss but not inherently superior to daily calorie restriction. Another meta analysis concluded that intermittent fasting resulted in ‘marginally’ greater weight loss in the short term, but that this came with slightly greater losses of lean body mass. Also, when looking at long term results, it arrived at a similar conclusion to previous papers, that there wasn’t much difference either way. It also stated that there appeared to be a higher risk of side effects with intermittent fasting protocols, including nausea, dizziness, feeling cold, mood swings and decreased energy levels.
One meta analysis included 11 studies and concluded that in observational trials, like the Ramadan research papers, Time Restricted Feeding resulted in a significantly reduced energy intake, between 200 and 350 calories per day. This resulted in more weight loss, obviously, but this often comes at the expense of some fat free mass. While in the controlled trials that compared Time Restricted Feeding to traditional calorie restriction, differences in fat mass and fat free mass tended to be very close. ‘Time Restricted Feeding promotes weight loss in the short term, probably because the caloric intake was overall reduced. Further larger high quality [randomized controlled trials] with longer follow ups are needed to define the impact of mealtime restriction on body composition, metabolic pattern and cardiovascular health.’ In fact, several of the most recent review papers that look at all fasting diets simultaneously, essentially conclude that fasting can work for weight loss but the differences when compared to regular calorie restricted diets appear to be small to insignificant. In short, until more research is published, from a fat loss perspective, fasting is just a different vehicle that ultimately takes you to the same destination: calorie restriction.
As research tends to show that fasting methods offer similar body composition changes to regular dieting when your total calorie intake is kept the same, it does essentially show you that you have a lot of flexibility on when you consume food and allows you to adjust to suit your personal preferences.
For example, if you are someone who doesn’t feel hungry in the morning, you don’t need to force breakfast down thinking it helps ‘kickstart your metabolism’ or anything like that. You can feel safe in the knowledge that eating your breakfast a bit later is a perfectly viable option. If you prefer to skip breakfast altogether and eat a bigger lunch and dinner, this is also an option.
If you prioritize minimally processed foods with a low energy density, this is always going to be a great strategy for appetite regulation. From that perspective, the paleo diet sounds very solid, and it is no wonder that it often results in weight loss and improved health markers.
The best take home message is that diets revolving around lean meats, fish, fruits, vegetables, nuts and eggs often result in weight loss and improved health markers even when people are consuming as much of these foods as they want.
There is a balance between prioritizing nutrient dense minimally processed foods but not being so restrictive that it is impossible to stick to and sucks all the joy out of your life. That will look different for everyone, so you can focus on improving your diet quality in a way that is appropriate for you, like emphasizing the foods you want to eat more of and naturally displacing some of the foods you may want to eat less of.
As an interesting side piece of information, participants were also asked to complete a ‘Barriers to Weight Loss’ checklist. Three of the most common barriers were being prone to stress related eating, being predisposed to eating when bored and thinking in black and white, all or nothing terms, which reiterates the importance of the underlying psychology and the cognitive flexibility concept.
The summary of the review paper’s findings is: the Mediterranean diet has potential for reducing central obesity, but it cannot be confirmed whether it is superior to other methods. Given that there are ‘few to negligible risks involved with consumption of this healthy eating pattern’, a Mediterranean diet could be a worthwhile strategy to consider. After all, given that we know any calorie controlled diet will promote weight loss in the short term, it is prudent to pick one that is healthy.
The Mediterranean diet is widely regarded as health promoting and following it can also be good from a weight management perspective as the emphasis on food quality will often nudge you towards consuming fewer calories even if it isn’t your main goal.
You do not need to follow a strict Mediterranean diet. It is possible to reap benefits from simply prioritizing some of the same foods, like fruits and vegetables, whole grains, fish, seafood, poultry, legumes, nuts and olive oil. Focusing on these and letting them displace less nutrient dense foods is always a great idea.
The study found that vegetarians and vegans consumed less meat, fish and poultry compared to meat eaters, obviously, but they also consumed significantly higher amounts of legumes, nuts, whole grains, fruits and vegetables. On top of this, non meat eaters consumed lower amounts of refined grains, fried foods, alcohol and sugary drinks. In general, this study would suggest that non meat eaters likely have healthier diets than meat eaters, on average. This has also been supported in other research, suggesting vegetarians tended to smoke less, drink less alcohol at weekends, use less prescribed medication and perform more intense exercise than their non vegetarian counterparts. This is one reason why it is quite common to conclude that vegetarians have lower Body Mass Indexes on average than meat eaters. Their overall lifestyles are often different and it’s not just about whether they are consuming animal products or not.
This aligns with the energy density theory: if you can increase the portion size for the same number of calories, people tend to eat less. For example, a meal of steak and avocado could be much smaller on your plate than a calorie matched meal of whole grains and lentils, so a lot of people might find the former easier to eat in larger quantities than the latter.
For a long time, plant based diets have been viewed as probably inferior from a lean body mass perspective. First, the amino acid profile from plants tends to be less conducive to muscle recovery than the profile of animal products, on average.
It took one group of habitual omnivores and one group of habitual vegans, who used supplemental protein to achieve a high protein intake of 1.6 grams per kilogram of protein per day (for a 220 pound human) in combination with a resistance training program. At the end of the 12 week period, both groups had similar results, suggesting that equal gains can be made on a vegan diet to an omnivorous diet, if proper planning is in place. This is great news for vegans, although it is worth keeping in mind that the supplemental protein that they required to hit their lofty protein target was higher than the other group, reiterating what the earlier research suggested: vegan diets quite possibly require a bit more caution in their prescription as people may very well gravitate towards a lower protein intake. Overall, when it comes to lean body mass growth or retention, some studies show similar results between groups and others show favoritism towards animal protein sources. Although it might not be a huge difference between the two, animal protein sources probably come out at least slightly superior, as confirmed by a meta analysis of 16 studies.
If you switch to a plant based diet, it’s highly likely that you will consume more fibre, ample fruits and vegetables and prioritize minimally processed foods like whole grains and legumes, as well as minimize many ultra processed and deep fried foods, and reduce your fat intake and the number of calories you consume, all of which is naturally conducive to promoting weight loss. These are all dietary patterns that you can apply to your own circumstances, even if you are following an omnivorous diet.
As plant based diets vary in levels of restriction, there could be a greater risk of nutrient deficiencies which means vegetarian and vegan diets may require more planning to make sure you are not missing out, hence studies often including B12 supplementation or additional protein powders.
Another research paper looked at a group of women enrolled in a commercial slimming program and found that flexible restraint was a better predictor of long term weight loss than rigid restraint. This brings us back to one of the key psychological concepts we discussed in the chapter on weight loss maintenance. Rigid all or nothing dietary restraint can backfire more than just cutting yourself some slack to begin with.
This is why there is a growing trend for people to move away from dietary restriction completely towards something called intuitive eating, which is often recommended as a safer alternative. By removing dietary rules aimed at weight loss and focusing solely on internal hunger cues, appetite and satiety, the effect on your relationship with food may be improved. There is a growing amount of research suggesting it is associated with positive psychological constructs including body image, well being and self esteem.
For example, you could aim to eat protein multiple times a day, which we know is good for maintaining lean body mass and promoting fat loss, and allow yourself a wide range of micronutrient dense foods, but ultimately let your own internal hunger cues guide how much food you eat, rather than relying on external cues like eating to a predetermined calorie goal. For most people who are just trying to find a balance between feeling healthy and regulating their body weight, it makes sense to ensure you are not constraining yourself with dietary rules that are any stricter than necessary.
The easiest dietary advice in the world would be to ‘only eat minimally processed nutrient dense foods and strictly avoid everything ultra processed’ as we have seen time and time again that diets revolving around minimally processed foods can help with weight management. However, in a world where ultra processed foods are becoming increasingly available, we must understand that prohibiting you from ever eating them comes with risk and that can blow up in your face if you are not careful.
Nobody thinks eating a single salad is going to give them a visible six pack and improve their health immediately, so why do we act like eating one measly slice of cake is going to ruin your health and make you gain body fat? Your overall calorie intake and diet quality matters far more than individual food items within that.
If you want to succeed at losing body fat and improving your health in the long term, the goal is to strike a balance between adopting health promoting behaviors and not going so far that it sacrifices your physical and mental health.
‘In conclusion, our findings indicate that there is little robust evidence that reducing meal frequency is beneficial.’ This is a very detailed way of saying that, while it is quite possible that changes in meal frequency may have other physiological effects that haven’t been fully studied yet, when it comes strictly to body composition, there doesn’t appear to be any really powerful evidence that you should strive for a specific number of meals.
Therefore, it makes sense to opt for personal preference rather than striving for a specific meal frequency.
Everything has a unique dose response relationship, even things we view as beneficial. Too little exercise is unhealthy but too much exercise is also unhealthy. If you don’t drink enough water, you will die but if you drink too much you will also die. Foods naturally contain many contaminants like heavy metals in trace quantities, but we don’t automatically expect those to cause health issues in any quantity whatsoever otherwise we wouldn’t eat anything at all.
One trial designed isocaloric diets to compare the effects of a high and low sugar intake, one with 25 percent and the other with 10 percent of participants’ total energy intake coming from sucrose. Both diets were designed to be identical apart from that, matched for calories, macronutrient distribution and fibre intake, so everything was in place to maximize the ability to assess the impact of sugar intake specifically. To help keep variables as controlled as possible, food portions were calculated and provided to the participants. At the end of the six week intervention, no changes in body weight were observed. Do you know why? Because participants were fed diets that were calculated based on their maintenance requirements. This demonstrates why total calorie intake is more important than the proportion of sugar within that calorie intake, at least up to the 25 percent dosage that the researchers looked at. Another trial also compared isocaloric diets, but this time with an even bigger discrepancy in the low and high sucrose intakes. The low sugar group consumed 4 percent of their diet as sucrose and the high group consumed a whopping 43 percent of their calories as sucrose. Just so we are crystal clear here, 43 percent of a diet coming from sucrose is higher than most people would likely ever get to. Participants in the high sugar condition were given Kool Aid powder alongside their breakfast, jelly and marshmallows alongside sweetened iced tea powder with their lunch and meringue cookies at dinner. Trying to go higher than that would be pretty difficult unless you started removing other food items to make room. Like the previous trial, both diets had identical macronutrient distribution, so the amounts of protein, carbohydrate and fat were the same, but this time they were designed to be hypoenergetic (putting people in a calorie deficit). Food was measured out and provided to participants to help ensure accuracy. What do you think the differences in body weight change were at the end of the trial? There were none. Both groups lost similar amounts of weight.
Naturally, this does not mean that diets super high in added sugars from jellybeans are the best thing you can do for your health, and nobody would ever encourage that, but the evidence suggests that sugars are fattening based on their calorie content, not because they have magical fat storage powers that other carbohydrates do not possess.
‘Although the available evidence indicates that the consumption of sugar sweetened beverages is associated with body weight gain, and it may be that fructose is among the main constituents of these beverages, energy overconsumption is much more important to consider in terms of the obesity epidemic.’
It is very easy to chow down a bag of jellybeans containing several hundred calories, but much more difficult to eat multiple apples consecutively for the same calorie total. This is one reason why putting all sugar containing foods under the same umbrella is very short sighted. For example, fruit, specifically, does not appear to be linked to weight gain in the same way that sugar sweetened beverages are. A systematic review concluded that fruit consumption is unlikely to contribute to excess energy intake and weight gain, as longer term studies where participants eat more fruit tend to show weight maintenance or modest weight loss, and shorter studies show that fruit has a much greater impact on satiety than more calorie dense sources of sugar.
It is true that a lot of the highest ranking offenders do tend to contain high amounts of sugar, as well as having an appreciable fat content. The ultra processed food items that are high in sugar but not fat, like non diet sodas and gummy candy, are ranked lower for addictive like properties, and the unprocessed foods that are high in sugar but low in fat, like fruit, sit near the bottom of the list. As we also saw, when comparing the unprocessed foods only (categorized by whether they had no added refined carbohydrates or fats), items that tended to be high in fat and salt (i.e., that are comparatively low in sugar), like steak, eggs, nuts and bacon, were more likely to be addictive like than fruit, suggesting that many things can make you want to eat more of a food, but sugar probably isn’t even the main culprit.
In one study, participants were given approximately 450 calories of jellybeans or soda to consume per day to compare the effect of liquid and solid calories, both primarily from sugars. The rest of their diet was not controlled, which allowed the participants to adjust it naturally without being prescribed a specific amount of total food per day. Following the 28 day soda phase, participants had gained weight, but following the 28 day jellybean phase, they had not. When consuming the additional jellybeans, participants had compensated by reducing their food intake elsewhere, but they did not when consuming the soda. This doesn’t show that sugary drinks are more fattening on a calorie for calorie basis, but it does show that they are easier to consume in excess.
There is always going to be an ongoing debate around whether sugary foods themselves are harmful and if so, at what dose. What we should all be able to agree on is that some foods containing sugar are more micronutrient rich, harder to overeat and linked with better health outcomes than others. You do not want to lump all foods that contain sugar under the same umbrella. Food is far more complex than its macronutrient content alone.
The easiest way for you to regulate your sugar intake is to minimize your consumption of sugar sweetened beverages. Liquid calories are notoriously poor at regulating your appetite compared to solid foods, so limiting the number of sugary drinks you consume is a sensible behavioral choice if you want to lose body fat.
It is far easier to eat sugar in excessive quantities when your diet is high in ultra processed foods than minimally processed foods.
Even if you consume it without any other ingredients because you are one of those people who likes drinking spirits straight without any mixers, the calories can quickly add up. A popular global brand of beer containing 5 percent alcohol has 42 calories per 100 milliliters, while a global wine brand quotes 72 calories per 100 milliliters for their 11.5 percent alcohol sauvignon blanc. When you consider that people tend to drink these by the pint and large glass, the calorie content can rack up much faster than you might realize.
To test the impact of alcohol on appetite, one study had participants come into the lab on three separate occasions and gave them either a non alcoholic lager, the same lager with one unit of alcohol or the same lager with four units of alcohol. These drinks were consumed 30 minutes before lunch to see whether it changed how much food they ate afterwards. When consuming the lager with one unit of alcohol, there was no increase seen in appetite, but after consuming the lager containing four units of alcohol, hunger ratings were significantly higher over the course of the day, which corresponded with an increase in food intake. Here we can see the increase in hunger after consuming four units of alcohol in an otherwise identical drink. So, if you have a large glass of wine with dinner (containing around two to three units), it is quite likely you won’t notice much difference in how much food you eat, but if you consume two or three glasses, you may notice a significant increase in hunger which can persist for several hours.
Another study tested whether alcohol has an impact when consumed either prior to a meal or alongside it. This study design sounds like the type of thing a lot of people would willingly sign up for, as participants had to go into a lab and eat a two course lunch of garlic bread and pizza with some wine. There were three conditions:
For the small subset of really nerdy folk among you who love this kind of detail, when consuming alcohol and protein together, muscle protein synthesis was 24 percent lower than when protein was consumed in isolation. When carbohydrates and alcohol were consumed together, it was 37 percent lower. This essentially means if alcohol kicks your muscle protein synthesis to the floor, protein can at least help it get back up to its knees.
The impact of alcohol on muscle growth and fat loss in the long term is still speculative. Just because someone’s recovery from a single session of exercise might be impaired, it doesn’t mean that doing this once per month would translate to any significant differences over 12 months of training. A speed bump might feel like it slows you down at the time, but a single speed bump over the course of a long journey doesn’t mean you get there significantly later.
What we really need is a study that lasts at least a few weeks with everyone following the same workout program, but some of the participants drink alcohol and the others don’t. Then at the end of the trial, we actually measure body composition changes. Thankfully, we do have precisely this research.
At the end of the study, changes in fat mass and fat free mass were similar across all training groups, regardless of whether they consumed alcohol or not. A follow up study with the same design also concluded that moderate alcohol consumption doesn’t significantly impair cardiorespiratory fitness either, so it seems to be quite possible to improve your fitness levels while still consuming alcohol, at least to a point. Of course, it is important to keep in mind that long term research on this is very limited.
From a body composition perspective, consuming a lot of alcohol can contribute to you gaining fat because of its calorie content, plus the fact it often makes you feel hungrier, so you also eat more food. It can also impair your muscle recovery and mess with hormone production (depending on your sex and age, perhaps) so if you drink a lot, you are probably undermining your performance in the gym and any lean body mass gaining goals you might have, at least a little bit.
Thankfully, after all the previous papers were published, there has since been a trial that compares continuous calorie reduction with a two day per week refeed strategy.
From working with clients for over a decade, I can tell you that a lot of people do this naturally via this thing called ‘the weekend’. It is common for people to have a more controlled food intake for five days of the week if they work a typical Monday to Friday job and then eat more on a Saturday and Sunday.
What were the results? Fat loss was similar between groups, however participants who were refeeding maintained more fat free mass and better preserved their resting metabolic rate, which we know tends to decrease as people lose weight. Even if it didn’t result in significantly more fat mass lost, two day refeeds were advantageous for holding onto lean body mass, which is something most people would want to achieve. Even though there was some debate on the statistical method being used, even a more critical analysis of the data concluded that the group implementing refeeds maintained more dry fat free mass (fat free mass minus total body water). Basically, refeeds might help retain more muscle tissue, maybe.
These results suggest that diet breaks could be advantageous from a fat loss perspective, but it comes with an extension of the total dieting period, which may be viewed as a disadvantage by some people. In short, would you prefer to diet for 16 weeks consecutively or for 30 weeks with interspersed periods of maintenance calories? That is what it would boil down to. One being ‘better’ is only really relevant if you actually want to follow the plan.
Psychologically, some of you may prefer the idea of ‘planned hedonic deviations’ (eating slightly more food for a day or two, like a refeed) or ‘non linear dieting’ (eating more food on some days or some weeks) to the idea of dieting on the same amount of food every single day. If this appeals to you, allowing yourself more food on some days might be a great idea. It’s normal to want to eat more food on some days when you feel slightly hungrier or maybe because you have social events, so having the flexibility to do this makes sense.
I would strongly discourage the idea of ‘cheat meals’ or ‘cheat days’ where you give yourself a free pass to eat unlimited quantities of foods you would normally prohibit. If you are dying for the idea of a ‘cheat day’ so you can eat a specific food, it is worth considering if prohibiting that food for the rest of the week is doing more harm than good.
Self monitoring is often considered so important that it has been described as ‘the cornerstone of behavioral treatment for weight loss’.
In simple terms, think of it like the owner of a company implementing a new business strategy. If they are watching their profits, they can assess whether it was successful and if not, they can tweak what they are doing to improve the outcome.
The closest thing most people get to having their body composition measured is stepping on the scales and seeing how much they weigh. Of course, this won’t actually tell you about fat mass or lean body mass specifically, but it is quick and easy. A lucky few may have access to fancy stuff like DEXA scans or hydrostatic (underwater) weighing equipment, but the most accessible tools to measure your body fat percentage are not particularly accurate. You could buy a skinfold calliper and use it yourself, but this would be about as reliable as a blindfolded monkey throwing at a dartboard. Digital scales that guess at our body fat percentage will likely have increasing accuracy as technology improves but, at the time of writing, aren’t something to really put a lot of faith in.
Your body weight fluctuates a lot and doesn’t necessarily indicate a change in fat mass. People can suddenly gain weight based on their menstrual cycle, what they ate for dinner and whether they have been to the bathroom or not. Your weight literally changes over the course of every single day, which is one of a bazillion reasons why you shouldn’t obsess about the number on the scales.
However, weighing yourself regularly has been shown repeatedly to help with weight loss. If the number trends down over time you know you are in a calorie deficit and if it trends up, you know that you are in a calorie surplus. Having this information allows you to change what you are doing if you want.
Just because weighing yourself can help with weight loss doesn’t mean it’s always a great idea for everyone because we know that health is far more multifaceted than how much you weigh.
While 93 percent of the smartphone group stuck to the plan, only 55 percent and 53 percent respectively of the website and paper diary groups did so, indicating that tracking food on your smartphone might be significantly more convenient and therefore easier to continue with. This is probably because it requires less effort to search and select a food item on your phone which then automatically calculates the calorie values for you, and also because a lot of people carry a smartphone, but rarely have a notebook sitting in their back pocket.
If you feel like you are struggling to lose weight and have absolutely no idea how many calories you are consuming, it may be helpful to learn more about the calorie content of foods you eat regularly. In a world that has a growing number of calorie dense foods, it can be eye opening to have more calorie awareness and this often helps inform people to make the simplest of changes.
If you are someone who already tracks their food intake, please understand that it is extraordinarily difficult to accurately record how many calories you are eating and some of the reasons for this are entirely out of your control. Even food labels in some countries are allowed to have margins of error of up to 20 percent, so if you buy a snack from the store, the actual calorie content could be up to 119 percent of what it says on the label. Trying to record your calorie intake absolutely perfectly would require a level of obsession I could never encourage. You would have to weigh every single thing you ate, including every ingredient you cooked with, and this level of meticulousness could be disastrous for your mental health.
Even though calorie tracking can be notoriously inaccurate, it can still be a useful tool. You don’t need to know exactly how much money you are spending and earning every single day to make periodically checking your bank balance worthwhile. Just having more awareness can be a good thing so don’t freak out at the idea that you don’t know exactly how many calories you are eating. It is of course entirely possible to improve your health and lose body fat without tracking your calorie intake at all. It is a tool, and not a tool everyone wants to use.
A later study directly tested whether sleep deprivation actually impacts how much people eat, rather than just measuring changes in hormones that are related to appetite. To do this, participants slept in a lab on two separate occasions for either four hours or eight hours. After sleeping for only four hours, they ate an average of 22 percent more food, which equated to 559 more calories. Although there was an average increase, the effects were even more pronounced in some people, who ate 36 percent more food, while the opposite was seen in a minority group, who actually ate 15 percent less food. This is an example of how people can respond in totally different ways to the same situations and why looking at the overall averages might hide important parts of the puzzle.
In short, less sleep won’t stop you losing weight, but it can skew it away from fat loss towards losing precious lean body mass, which isn’t ideal.
For the participants aiming to improve their sleep quality, the following action was recommended, as much as possible: •Keep the room you sleep in dark, quiet and cool. •Go to bed and get up at the same time every day. •Go to bed at a time that means you can get eight hours of sleep. •As soon as you get up in the morning, expose yourself to as much natural light as possible. •Try to get enough sleep that you do not need an alarm clock to wake up. •Do not use electronic devices that emit light in bed. •Learn a relaxation technique and use it to fall asleep at night or if you wake during the night. •Two hours before bed: •Turn down the lights •Put away computers, tablets and mobile phones, or use a blue light filter and the lowest possible light setting. •No exercise. •No food, coffee or black tea, or energy drinks (your last cup of coffee for the day should be a minimum of six hours before bedtime, ideally). •Do calm and positive activities and do not bring up relationship conflicts before bedtime.
If you have good sleep quality, this can naturally help regulate your appetite, encourage you to consume less food, improve your performance in the gym, help retain lean body mass when dieting as well as increase the amount of body fat you lose.
Although it might not result in a huge, groundbreaking difference, the researchers pointed out that it is also an extremely simple strategy to implement, because telling people to drink water prior to main meals is about as easy as weight loss advice can ever get.
Although there is some research showing that drinking water can promote weight loss, it is primarily in the context of drinking a large volume before eating and I am fearful that some people would drink far more water than their body needs simply to try and override their natural hunger signals.
As softer foods require less chewing than harder foods, it makes sense that the time between mouthfuls would be reduced. One study gave participants variations of the same meal consisting of potatoes, carrots, steak and gravy. In one meal, these ingredients were served whole, while the other used mashed vegetables and small pieces of meat instead, all of which required less chewing. When the food was mashed, the eating rate (grams of food consumed per minute) was approximately 20 percent faster, which also nudged people towards consuming more calories overall. Same foods, same taste but simply a change in texture was enough to influence how fast someone eats and, inadvertently, how much food they consume.
Rather than manipulating food texture or changing the utensil that people use to eat their yoghurt, one study implemented the glaringly obvious and just told participants how many times to chew their food, either 15 or 40 times per mouthful. When they could consume as much food as they wanted, chewing more times resulted in 11.9 percent less food being eaten and some significant differences in gut hormones related to appetite. In a later study, a series of audible bleeps were used to cue participants to take a mouthful of food, so they could compare the difference between eating a portion of food in six minutes or 24 minutes. This time, instead of seeing how much food they would eat at that meal, the portions were kept exactly the same, but their food intake was measured three hours later when they were given a selection of cookies and crisps (or chips, in American terms). When they had eaten the same sized initial meal slowly, participants ate 25 percent less food at the subsequent sitting, now showing us that reduced eating rate can impact later food intake as well.
I am obviously not telling you to eat all your meals with small cutlery, or chop it up into small chunks, or set an audible bleep so you know when to have your next mouthful. These are simply the methods used in research to slow down how fast someone eats so they can measure the impact. But they still teach us some interesting things about appetite regulation. For example, the foods that you eat more quickly are likely to be easier to eat in volume and at speed. It has been proposed that part of the reason people eat more ultra processed ‘junk’ foods is simply because there is a tendency to eat them faster than unprocessed foods.
If you were in a speed eating competition, taking bigger mouthfuls, barely chewing, not pausing between mouthfuls, and not pausing between platefuls would be the best strategies to eat as much food as possible before your appetite signals tell you to slow down, so it makes sense that how fast you eat can impact how much you eat.
Even though hunger scores were similar across all study days, participants ate an average of 11.6 percent more food when they were watching TV or listening to the audio story. The theory here is that environmental conditions can distract people, so they eat more food even if they aren’t feeling hungrier.
If you are someone who enjoys distractions when you are eating, like watching TV or scrolling on your phone, there is a strong possibility that this is nudging you towards consuming a bit more food and over time this might tally up.
If you feel inclined, minimizing distractions while you are eating might be worth considering. Like eating dinner at the table instead of in front of the television or taking a break from your laptop for lunch instead of eating and working simultaneously. This may allow you to pay more attention to hunger cues and naturally result in you feeling less hungry, without you having to change the foods you are eating.
Whatever your goal is, let’s unanimously agree to say goodbye to overhyped, short term fad diets and say hello to making educated decisions that are best for your health in the long run. Let’s also say goodbye to unknowingly sacrificing your well being just to fit into a pair of skinny jeans or see a particular number on the scale. I think we can all agree, there are better things to do with your life than constantly worry about how much you weigh.