Published May 3, 2024
In today’s blog post, we will look at the ten key factors that have been shown to trigger overeating and increase calorie intake and body weight. If we overeat meal after meal, we will gain weight. And that is even though—believe it or not—our bodies defend against weight gain almost as much as against weight loss.
Understanding and minimizing the factors that can make us overeat is, therefore, our best chance of preventing weight gain, and it’s also an essential step to losing some weight if we carry extra body fat, particularly if we want to have a chance to keep it off.
Trigger #1: Sleep deprivation
We have a lot of evidence that not getting enough sleep increases calorie intake and leads to weight gain. What sleeping enough means is certainly different from person to person, but it’s usually assumed that someone sleeping 7-8 hours a night is getting enough sleep, while less than 7 hours is considered too little.
In observational studies, people who do not sleep enough tend to weigh more and also gain more weight over time than people who sleep enough.
We also have more than 50 randomized controlled trials in which participants were experimentally sleep-restricted. And pretty consistently, even just one or two nights of restricting someone’s sleep duration can measurably increase how hungry they are throughout the day and how much food they spontaneously eat. Cumulatively, we have strong experimental evidence that sleep restriction leads to a significant increase in calorie intake and body weight, and also that being sleep deprived makes it harder to lose weight.
Let’s take a closer look at one of these randomized controlled trials. These authors studied twelve healthy, young, non-obese men and women. That’s a small study, but this was a very well-controlled randomized cross-over design study where each participant served as their own control. Each participant completed each of two study phases, in random order: once, their sleep was restricted to four hours per night for 14 days, while during the other study phase, they were allowed to sleep up to nine hours per night. In both phases, they stayed as inpatients in a hospital, which allowed investigators to monitor how much they slept, and also to measure what they ate and how much.
As summarized in the figure above, when participants were experimentally sleep deprived, they ate, on average, 308 kcal more per day than when they were getting enough sleep. Three hundred kcal per day is a huge amount. So it’s not a surprise that the participants gained about a pound of body weight during this sleep-restricted period. That may not sound like much, but in people who are not trying to gain weight, and in just two weeks, that is quite meaningful.
And lastly, sleep restriction led to a substantial increase in visceral fat. That’s the fat tissue deep inside the belly, marked yellow in the figure above. Visceral fat, sometimes also called intra-abdominal fat, is a type of fat that is strongly linked to low-grade chronic inflammation and insulin resistance. As explained in a prior blog post, fat tends to accumulate in visceral fat tissue when the primary storage site for fat in the body, the subcutaneous fat tissue right under our skin, is filled to capacity and can no longer effectively store fat. This research shows that sleep deprivation is another mechanism through which body fat can preferentially become deposited in the visceral fat depots. Not a good thing.
So, in summary, this and similar studies show clearly that being sleep-deprived makes people eat more and gain weight. This effect can be seen after just one or two nights of sleep deprivation. Now, some of the experimental studies, such as the one discussed above, created a huge sleep deficit by allowing people to sleep only for 4 or 5 hours a night. However, after reviewing this literature, my conclusion would be that even mild sleep deprivation is likely to increase calorie intake and body weight modestly. Over many years, this could be a big factor. If you need seven hours of sleep a night and you consistently only sleep six or six and a half hours, that could very well contribute to a meaningful increase in calorie intake and body weight over time.
I can actually share a little anecdote here: the only time in my life when I gained some weight was when both of our children were babies. There was a period when we were constantly woken up by one of the two, and would sometimes just get four or five hours of interrupted sleep a night. And on the days following these nights, both my wife and I would be roaming the house constantly looking for some high-calorie snacks, eating an entire pint of ice cream or a large bag of potato chips in one sitting. Even though I understood the science behind this and knew that this was probably the result of the massive sleep deprivation we were going through, there was little I could do about it.
The conclusion here is: make sure to get enough sleep every night! Not only do we feel better and are more productive, but getting enough good quality sleep every night should be seen as a cornerstone of a healthy lifestyle, including a healthy body weight.
Trigger #2: Low Blood Sugar
Normally, when we speak about low blood sugar levels, clinically also called hypoglycemia, we mean a blood glucose concentration of less than 70 mg/dL, or 3.9 mmol/L. And being hungry is one of the classic symptoms of clinical hypoglycemia, so developing clinically low blood sugar levels could induce food intake and potentially increase overall calorie intake throughout the day.
However, there is now some evidence that a drop in blood sugar levels below our normal baseline level could trigger hunger and calorie intake even if the blood sugar level doesn’t drop into the clinical hypoglycemic range. For example, let’s assume your normal fasting blood sugar level is 90 mg/dL. You eat breakfast, and your blood sugar level rises, and then ideally, it drops back to baseline. One study shows that if the blood sugar level after a meal drops below the baseline value, as illustrated in the figure below, then the person gets more hungry sooner, eats sooner and more, and has a higher calorie intake throughout that day. The more the blood sugar level drops below baseline, the hungrier the person gets and the more calories they eat. And that’s the case even if the blood sugar doesn’t drop below the 70 mg/dL or 3.9 mmol/L that would qualify as clinical hypoglycemia.
There is another feature of the blood sugar response after a meal that seems to affect when we feel hungry again, and that is if the blood sugar level drops at a particularly rapid pace. So imagine that you eat breakfast, your blood sugar rises a lot, and then drops very rapidly back to baseline or even lower. In a case like that, there are some data to suggest that this period of rapidly falling blood sugar levels could trigger you to become hungry and look for food.
So when do we see this pattern of rapidly falling blood sugar levels or dips in blood sugar below our baseline level? We see it almost exclusively in response to highly glycemic meals that trigger a sharp rise in blood sugar. Because when our blood sugar rises quickly and a lot, our pancreas responds by producing large amounts of insulin to deal with all of the glucose. And because insulin leads to the removal of glucose from the blood, a lot of insulin can lead to a drop in blood sugar levels that is quite rapid and may also go too far. In a case like that, both the rapid drop and the dip in blood sugars would be expected to trigger feelings of hunger, which may lead to food intake. If the person then eats another highly-glycemic meal, then the entire cycle may start again and trigger another meal 2-3 hours later.
What should we do to prevent this? Well, the key is to prevent the initial blood sugar spike from developing, and the goal should be to keep blood sugar levels relatively steady throughout the day. I mentioned that such a blood sugar spike is almost always the result of eating a highly glycemic meal. What does highly glycemic mean? Well, it means rich in carbohydrates, for one, but more specifically, rich in carbohydrates that are rapidly absorbed, meaning that have a high glycemic index. Examples of high-carb foods that also have a high glycemic index would be drinks rich in sugar, such as soda, or toast with jam, a sugary cereal, cake, white rice, or potatoes.
To prevent blood sugar from rising too much too quickly, one option could certainly be to cut out all high-carb foods and follow a low-carb diet. If our meals consist mostly of protein and fat, then our blood sugar levels will be much more stable throughout the day. And if blood sugar levels are stable, this also means we don’t need nearly as much insulin, and the risk of insulin driving our blood sugar levels down too rapidly or too much is very much diminished. In fact, minimizing this trigger of overeating may well be one of the reasons why low-carb diets can be a good tool to help people control their hunger, cravings, and excessive calorie intake.
Alternatively, if someone prefers to eat carbohydrates, eating lower glycemic index foods would be preferable, and using strategies to avoid blood sugar spikes would help as well. Specifically, it would be important to avoid eating what we call “naked” carbs, but instead consume any high-carb food either with or after protein- and fiber-rich foods. So, for example, rather than having a piece of cake by itself in the middle of the afternoon, you could have the cake as a dessert after a lunch of salmon and roasted vegetables. For more detail, please take a look at my prior blog posts about the glycemic index and glycemic load of foods, and about strategies to avoid blood sugar spikes.
Trigger #3: Hyperpalatability
That’s a big-sounding word. What does it mean? Palatable means yummy. So hyperpalatable means more than yummy. What scientists mean when they talk about hyperpalatable food is food that is so yummy that whether we want it or not, we cannot stay away from it. And when we eat it, the food leads to some explosion of feeling good in our brains, and we need more and more and more. It’s those types of foods that, even though we are not really hungry or maybe just had a big meal, we still continue to eat.
I guess most of you will be able to tell if a food is hyperpalatable. And so the first thing I’d like to suggest is that you pay some attention to which of the foods you regularly eat may have this quality of hyperpalatability. What I actually find is that, yes, it does give me pleasure to eat these foods, but they also tend to make me feel awful afterwards because I just couldn’t resist them. So I try to just not have such foods in the house and focus on eating foods I like, but that I like in a normal way, not in the hyperyummy way that somehow hijacks my brain.
For those of you who want a bit more science here, there is a long list of colleagues who have devoted a lot of effort to trying to figure out what it is about food that we humans find the most rewarding. My colleague Adam Drewnowski, for example, has published several studies showing that humans find fatty foods such as heavy cream pleasant, and they also find sugar pleasant, but what they really like is the combination of fat and sugar. In research, we often call the pleasure we perceive when we eat a food reward, and it’s thought to be a key driver of overeating. This is similar to research done by Dana Small, who has also done work to demonstrate that the combination of fat and carbohydrates, specifically sugar, is more rewarding than either alone. So we’ve known for a long time that the combination of fat and sugar, in particular, is very highly rewarding, and that we humans tend to overeat foods that combine fats and sugars in the right proportions.
Another colleague, Tera Fazzino, has taken this a step further. Tera and her group have come up with objective criteria to identify hyperpalatability. This work is in an early stage, so the exact definitions may change in the future, but she suggests that hyperpalatable foods tend to fall into one of three categories:
- The first category is the combination of fat with simple sugars. That is exactly what we just discussed. Examples here include cake, ice cream, or brownies.
- The second category is characterized by a high content of fat combined with a high content of salt. Examples of these fatty and salty foods include bacon, hot dogs, or pizza.
- And the third category includes foods characterized by a high content of carbohydrates and salt, such as breads, crackers, pretzels, or biscuits.
In general, what we can see is that hyperpalatable foods include combinations of at least two factors, each of which by itself makes a food moderately palatable.
A book I can recommend on this topic is Salt Sugar Fat by Michael Moss, in which he explains how food companies used this knowledge about food reward and hyperpalatability to design foods with the right combinations of salt, sugar, and fat to make us buy and eat more of their foods.
My suggestion here is to watch out for these foods that meet these criteria, or that just make you feel like you cannot stop eating them even though you know you are no longer hungry. And note that while many of these are processed foods coming from a package, these could also include foods you cook or bake at home. Try to understand which specific combinations of fat, carbs (specifically sugar), and salt you regularly eat have this hyperpalatable effect on you, and try to stay away from them. For me, if someone brings peanut butter cup ice cream or certain potato chips into the house, that someone will quickly find out that people with a PhD in nutrition are not immune to the appeal of such foods …
Trigger #4: Soft texture
Research studies show pretty clearly that in the context of a meal, people eat a lot more calories if the food they are eating has a soft texture that requires little chewing, all other factors being equal.
The simple conclusion here is to eat preferentially hard-textured foods that require chewing. This is likely one of the many benefits of eating whole foods that are unprocessed or only minimally processed: whether it’s meat, broccoli, salad, or nuts, all of these require a lot of chewing.
Trigger #5: Fast eating speed
Maybe not a big surprise here, but definitely worth mentioning is that if we eat fast, we eat more calories. In professional research circles, the eating speed is measured as the eating rate, defined as the amount of food eaten, in g, per minute.
That a higher eating rate increases ad libitum energy intake may be related to the fact that the various satiety signals that cause our brains to realize that we’ve had enough do take some time to respond to the food we are eating. And if we eat very fast, without any pauses, we will manage to eat more calories before our brain registers that we are full.
The concrete suggestion here is to be mindful of your eating habits: sit down to eat, maybe have a conversation while you are eating, eat slowly and chew your food well, and take at least a short break between helpings or courses. If you eat a plateful of dinner fast, you could almost certainly immediately have another plate full. Still, if you take a break, you may realize that you are actually comfortably full already, or maybe you just need another few bites rather than another full plate.
Trigger #6: Larger serving sizes
Most people have heard about this one, but it’s worth repeating. If you ask people to eat to satiety, they will consume substantially more calories if the food is served in large portions.
There have been at least 18 randomized controlled trials looking into the effect of serving size, or portion size, on calorie intake. Let’s just take a look at one representative example. Here, the investigators asked about 50 men and women to come into the research clinic on four different days. Each time, they were served mac and cheese, and were asked to eat as much or as little of these as they wanted. The only difference between the four clinic visits was that the mac and cheese were served in different serving sizes: either 500g, 625g, 750g, or 1,000g, in random order. Each time, participants ate less food than they were served. See the left y-axis in the figure below; when they were served a 500g portion, they ate about 320g of the food so they could have easily eaten more. And what we can see is that just serving a bigger portion of the mac and cheese triggered greater food intake in these participants. On average, participants consumed about 270 kcal more when served a 1,000g serving of mac and cheese compared to a 500g serving. The interesting part is that there was no difference in feelings of satiety and hunger after these meals, so in all cases, participants supposedly ate until they were comfortably full.
From this research, we can conclude that all-you-can-eat buffets are not a great idea and that we should avoid serving large portions—probably not just on the plate but also in the serving bowls on the table right in front of us.
Trigger #7: Liquid calories
We have strong evidence that people tend to eat more calories in a meal if that meal contains liquid calories in the form of sugar-sweetened or alcoholic beverages. Several randomized controlled trials demonstrate that liquid calories are mostly consumed on top of whatever calories you would normally eat. As in the representative example illustrated in the figure below, if someone is served the same meal a few times, they tend to eat the same number of calories from this meal, around 600 kcal in this case. And that is independent of whether they are served water with the meal or a glass of soda or a beer, each containing 150 kcal. This means that the person would consume the soda or beer calories on top of the calories they eat in the form of solid foods. Their total calorie intake would be higher if their meal contained such liquid calories. And that effect seems to persist over time, such that people who regularly drink sugar-sweetened or alcoholic beverages tend to gain weight over time.
This is an important concept, and—in my opinion—reducing the consumption of sugar-sweetened and alcoholic beverages is one of the lowest-hanging fruits if someone wants to prevent or reverse weight gain and improve their general health. For more details, including all of the scientific references, please check out the dedicated blog post I’ve made about this topic.
Trigger #8: Low Satiety per Calorie
As I have explained in more detail in the last blog post, how many calories we need to eat in a meal until we feel comfortably satiated is largely related to the protein percentage, the fiber content, and the energy density of that meal. In general, a meal tends to be more satiating per calorie consumed if it has a higher protein percentage, a higher fiber content, and a lower energy density.
I also shared the Nourished by Science satiety score of foods that combines these three factors into a single number, from zero to one hundred, with higher satiety scores indicating more satiating foods. This score suggests that we can make our meals a lot more satiating if we base them on foods from two categories of highly satiating foods. The first category of highly satiating foods are those that have a high fiber content and low energy density, such as all kinds of vegetables, greens, lettuce, mushrooms, berries, and to some degree, fruit. Whole fruit, that is, not fruit juice. The second category of highly satiating foods are protein-rich foods, including legumes, seafood, unprocessed meat, eggs, Greek yogurt, and cottage cheese. If you focus most of your meals around combinations of foods from these two categories, you are doing a lot of things right. One whole food rich in protein plus one whole food rich in fiber that also has a low energy density. As illustrated in the figures below, examples would be a piece of meat, fish, omelet, or tofu with a large mixed salad or some sauteed vegetables. Or a bowl of Greek yogurt or cottage cheese with berries or fruit. Or you’ll add some legumes such as beans and lentils to a meal; these are fairly rich sources of protein AND fiber, and they also have a low energy density.
For more detailed information about the satiety score and the role of protein, fiber, and energy density in modifying how satiated we feel, please view the last blog post. That post also contains all of the references.
And if you would like to download the poster showing the satiety scores of common foods, you can do that here.
Trigger #9: Ultra-Processed Foods
Ultra-processed foods are industrial formulations that are made from substances isolated from whole foods, plus ingredients not normally used in the culinary preparation of foods. ‘Industrial formulations’ means that most of the time, these foods are designed in a lab, made in a factory, they are packaged, and usually have a long shelf-life. With ‘substances isolated from whole foods’, we mean that they don’t contain an ear of corn on the cob, but instead high-fructose corn syrup isolated from corn and modified in a lab, corn oil extracted from corn, and things like modified corn starch. So they are usually rich in isolated sugars or syrups of some kind, starches or modified starches, and isolated fats or oils. They are also usually rich in salt, and they contain food additives that are not normally used in a kitchen, such as emulsifiers, caking agents, thickeners, artificial colors, artificial or natural flavors, flavor enhancers, etc.
Based on the so-called NOVA classification system that categorizes foods based on their degree of processing, ultra-processed foods are in NOVA category four.
Now, ultra-processed foods are interesting because humans basically ate zero ultra-processed foods up until maybe 80 or 100 years ago, simply because we didn’t have the processing capabilities to make these types of foods. And what we can say clearly is that as the food industry in industrialized countries has produced more and more ultra-processed foods, we have seen the emergence of the obesity epidemic. Now, of course, many things in our diet and lifestyle have changed over the last 80 or 100 years, so it’s impossible to know to which degree ultra-processed foods are to blame. However, I’d say that several lines of evidence strongly suggest that ultra-processed foods have played an important role in the obesity epidemic worldwide, and that replacing at least some of the ultra-processed foods we are eating with unprocessed or minimally processed foods should be a top priority for anyone interested in the prevention and reversal of excess body weight.
For one, ultra-processed foods tend to have many of the other qualities that we have discussed in this blog post here and in the previous one about satiety that would make it likely that people overeat on a diet rich in ultra-processed foods. Ultra-processed foods tend to be low in protein; low in fiber; they have a high energy density, meaning that they have a lot of calories per gram; they tend to be highly glycemic because they usually contain sugar, syrups, and refined carbs, which means they tend to trigger major swings in blood sugar and blood insulin, which could give rise to low blood sugar levels; they are industrially designed to be hyperpalatable because they often are just the perfect combination of salt, sugar, and fat; they tend to have a soft texture; they are often eaten at a faster eating speed; they come in oversized packages, so large serving sizes; and many ultra-processed foods are also liquid calories, such as soda or energy drinks.
If we compare different countries, we find that the obesity prevalence tends to correlate with the percentage of foods consumed that are ultra-processed. Countries in which the majority of foods are ultra-processed, such as the United States, the United Kingdom, Canada, and Australia, have the highest obesity prevalence. In contrast, countries that have not yet adopted ultra-processed foods widely, such as these Southern European countries shown in the figure below (Italy, Spain, Portugal), have a much lower obesity prevalence.
And within each country, those who consume the most ultra-processed foods tend to weigh more and gain more weight over time.
Lastly, we have evidence from a well-controlled randomized controlled trial that free-living people who are served ultra-processed foods massively overeat them compared to a diet consisting mostly of unprocessed or minimally processed foods.
We can say with some confidence that eating a diet rich in ultra-processed foods triggers overeating and likely weight gain. Why that is, we can only guess at this point, but as I mentioned, most ultra-processed foods combine several of the triggers we discussed here that cause overeating. There may be other factors on top of the ones mentioned, but I personally feel strongly that what we know already is sufficient to recommend that people who are interested in preventing or reversing excess body weight aim to replace at least some of the ultra-processed foods they are eating with unprocessed or minimally processed foods from NOVA categories one to three here.
For more information on this topic, including all of the scientific references, please visit my prior blog posts about the global nutrition transition and about ultra-processed foods specifically.
Trigger #10: Psychological Factors
Now, I am mentioning this here because, of course, our own psychology plays a major role in our eating behavior, including which foods we eat, and how much food we eat. It is very clear that we often eat even though we are not really hungry, or we continue eating even though we are already comfortably full. Discussing the various psychological factors that could play into this, considering which of these may apply to our own situation, and taking steps to address them, is, in my opinion, a major key to a healthy body weight. I’ll discuss this in more detail in a separate blog post.
How I Use this Information
I have three fairly simple rules.
First, I do not regularly consume ultra-processed foods, sugar-sweetened or alcoholic beverages, or treats such as potato chips, candy, or ice cream. My view here is that it’s fine to enjoy any of these as an occasional treat, but I try not to make the consumption of any of these foods or drinks a regular habit.
Second, I incorporate a good portion of protein and a large portion of fiber-rich vegetables into most of my meals to make these more satiating per calorie. In my mind, if most meals are centered around a source of protein such as meat, fish, eggs, Greek yogurt, cottage cheese, tofu, beans, or lentils, PLUS a big pile of vegetables or salad, or maybe some berries and fruit, any of these are a great basis for a solid meal that’s difficult to overeat on. In this context, it is also important to limit isolated fats, oils, sugars, and syrups. All of these are isolated sources of energy that contribute nothing of nutritional value other than calories.
And third, my goal is to sleep eight hours every night. This is the hardest one for me to achieve regularly because I am a bit of a night owl, but I continuously make an effort to go to bed on time.
Now, why three rules when I have been talking the entire time about ten major triggers of overeating? Well, I wanted to make sure you know about all ten of these triggers, but at the same time, I think we can all agree that constantly considering all ten could easily ruin our enjoyment of eating, and it’s just impractical to constantly consider this many factors.
So I have been thinking about whether we cannot come up with one or a few simple rules that everyone can easily remember that would minimize our risk of overeating from all of these factors. The three rules are certainly not perfect, and they don’t address all triggers fully.
However, the first rule directly addresses ultra-processed foods and liquid calories as major causes of overeating, and also limits to a very large degree those foods that are characterized by low satiety per calorie, hyperpalatability, large serving sizes, and a soft texture that we tend to eat at a fast eating speed (see figure below). Of course, soft texture, a fast eating speed, and large serving sizes are not fully addressed by this rule, and people who want to lose weight may want to pay some attention to these as well.
The second rule directly increases how satiating our meals are per calorie, and because both protein and fiber reduce the blood glucose response to a meal, they also reduce the risk of a blood sugar spike leading to rapidly falling or low blood sugar levels. Incorporating a lot of whole foods rich in fiber or protein such as vegetables, berries, fruit, or meat also necessitates a lot more chewing and a slower eating speed.
Rule number 3, of course, directly addresses sleep deprivation as a trigger of overeating.
So, again, these rules are by no means perfect, and you are invited to find your own simple set of rules that you can easily implement in your life.
What I like about these rules is that they are fairly straightforward and can be implemented irrespective of which way of eating you prefer. Low-carb, low-fat, or a mixed diet, I think sticking to these rules could be helpful for anyone.
Feel free to comment below if you have any questions.
Until next time, take care.
References
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- Rogers et al.; The effects of sleep disruption on metabolism, hunger, and satiety, and the influence of psychosocial stress and exercise: a narrative review. Diabetes Metabolism Research and Reviews 2024; 40: e3667.
- Soltanieh et al.; Effect of sleep duration on dietary intake, desire to eat, measures of food intake and metabolic hormones: a systematic review of clinical trials. Clinical Nutrition ESPEN 2021; 45: 55-65.
- Wyatt et al.; Postprandial glycaemic dips predict appetite and energy intake in healthy individuals. Nature Metabolism 2021; 3: 523-9.
- Melanson et al.; Blood glucose patterns and appetite in time-blinded humans: carbohydrate versus fat. American Journal of Physiology 1999; 277: R337-45.
- Drewnowski et al.; Sweet tooth reconsidered: taste responsiveness in human obesity. Physiology & Behavior 1985; 35: 617-22.
- Drewnowski and Greenwood. Cream and sugar: human preferences for high-fat foods. Physiology & Behavior 1983; 30: 629-33.
- Thanarajah et al.; Habitual daily intake of a sweet and fatty snack modulates reward processing in humans. Cell Metabolism 2023; 35: 571-84.
- Fazzino et al.; Hyper-palatable foods: development of a quantitative definition and application to the US food system database. Obesity 2019; 1761-8.
- Bolhuis and Forde. Application of food texture to moderate oral processing behaviors and energy intake. Trends in Food Science & Technology 2020; 106: 445-56.
- Argyrakopoulou et al.; How important is eating rate in the physiological response to food intake, control of body weight, and glycemia? Nutrients 2020; 12: 1734.
- Robinson et al.; A systematic review and meta-analysis examining the effect of eating rate on energy intake and hunger. American Journal of Clinical Nutrition 2014; 100: 123-51.
- Higgins et al.; Systematic review and meta-analysis on the effect of portion size and ingestive frequency on energy intake and body weight among adults in randomized controlled feeding trials. Advances in Nutrition 2022; 13: 248-68.
- Rolls et al.; Portion size of food affects energy intake in normal-weight and overweight men and women. American Journal of Clinical Nutrition 2002; 76: 1207-13.
- Valicente et al.; Ultraprocessed foods and obesity risk: a critical review of reported mechanisms. Advances in Nutrition 2023; 14: 718-38.
- Dicken and Batterham. The role of diet quality in mediating the association between ultra-processed food intake, obesity and health-related outcomes: a review of prospective cohort studies. Nutrients 2021; 14: 23.
- Lasschuijt et al.; Speed limits: the effects of industrial food processing and food texture on daily energy intake and eating behavior in healthy adults. European Journal of Nutrition 2023; 62: 2949-62.
- Forde et al.; Ultra-processing or oral processing? A role for energy density and eating rate in moderating energy intake from processed foods. Current Developments in Nutrition 2020; 4: nzaa019.
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10 Responses
Great job, Mario.
A couple nitpicky observations:
– # 5 (faster eating speed) and #6 (larger serving size) — this only applies to HEDONIC foods (carbs+fats, fats+salt, fats+carbs+salt…e.g cake, ice cream, chips, donuts, salted peanuts, doritos, etc) — a plate with high protein/energy ratio (e.g. grilled salmon over grilled asparagus) is self limiting for speed and size, sending strong signals of ENOUGH to the brain. Why? Because the body cannot store either protein or fiber, so their influx is self limiting by design.
-#2 (low blood sugar) — I think this is complex and would merit a separate video — indeed, hypoglycemia will induce food craving, however, this depends more on the subject’s metabolic health and less on the food type (hyperglycemic food). A lean, metabolically healthy subject will not usually go thru this precipitous blood glucose drop, because lean developed muscles act as energy “sinks” which take energy in slowly. A diabetic subject, which usually has “marbled” and/or sarcopenic muscles will have a lot of energy backflow already in their blood, plus exogenous insulin administration will make things worse.
Overall, congrats for another excellent video!
Andrei
Hi Andrei,
Not nitpicky at all; very good observations.
Regarding your comment to #5 and #6, I’d agree you are at least partly correct. And for that reason, I did consider to not include these in the video, and that’s also why I only indirectly address them in my three rules. However, I am a little less certain than you that the effect of faster eating speed and larger serving size is dependent upon hyperpalatable or energy dense foods. It’s possible, but I am not sure, because the studies particularly on #6 are pretty consistent independent of what is fed to research participants.
Regarding hypoglycemia, you are – of course – correct that highly glycemic meals do not cause a blood sugar spike or a rapid drop in blood sugar or low blood sugar in someone who has 100% normal glucose tolerance. However, I do think this is very relevant because 80+ of adults in most countries are not 100% glucose tolerant these days. If you argue that I should have added that qualifier, you are not incorrect …;-)
Cheers
Mario
Thank you for sharing all these! It is helpful.
One question, when we talking about low blood sugar, which sometimes goes under normal range.. When someone has insulin resistance, blood sugar cant go to muscle cells, but can go to fat cells for example, and in that way we can experience low blood sugar (even though some of our cells are resistant to insulin). Just to confirm if I am right?
Thanks for the answer in advance
Hi Jovana,
No, that is not correct, at least not usually. It is possible to have insulin resistance restricted to a specific type of tissue, but in most people who are insulin resistant, we see some insulin resistance in all insulin-sensitive tissues (fat tissue, muscle, liver).
It is more common to see hypoglycemia in someone who just produces too much insulin, but is still fairly insulin sensitive. For example, some people have a diminished first-phase insulin response, which causes blood sugar to rise a lot immediately after a meal. And once blood sugar levels are very high, the second-phase insulin response may trigger a very large secretion of insulin. And then that hyperinsulinemia may bring blood glucose levels down too fast and too far.
You can learn more about this in the blog post linked below; see my response to question 6:
https://nourishedbyscience.com/blood-sugar-spikes-qa/
Cheers
Mario
Thank you a lot for the answer
Excellent article, great research, clear practical recommendations! Thank you Mario
Thank you! Appreciate that you took the time to comment.
Cheers
Mario
Excellent video, lots of very useful, helpful information to understand what is going on inside of us. A couple of questions, is our base line glucose our fasting glucose? would that be personal to each individual? Is it ok if it is over the recommended reference values? ie. my fasting glucose level seem to be 6.35 mm/ol (1.14 g/l). the reference values, here in france are 4.11 mm/0l-5.88mm/dl and (0,74-1,06 g/l). I am finding that I get light haded at 110 up to 120 mg/dl and needing to top up!!!! Would that be my personal lo blood sugar level/ These videos are so interesting and education..They can help us to figure out what is going on for us individually, which, unfortunately the doctors do not have time for!!!! Thank you sooooo very very much for taking the time to educate us..
Hi Linda,
I am not sure I fully understand your question. Generally, we want our fasting glucose to be below 100 mg/dL (5.7 mmol/L). And ideally, our blood glucose should return to under 100 mg/dL in-between meals. However, here, we don’t have a clear diagnostic criterion whether it’s bad if our blood glucose drops only to, say, 110 mg/dL about 2 hours after a meal.
However, if your fasting and baseline glucose level never or rarely drops below 110 mg/dL, I would encourage you to speak to a doctor, as it could be a sign of prediabetes.
The observation that you feel light-headed if your blood glucose drops below 110 mg/dL is surprising. Usually, we develop symptoms of low blood sugar (hypoglycemia) only below 70 mg/dL, and cannot feel changes in blood sugar in the range you are talking about. Could it be something else that makes you lightheaded? If this happens frequently, I would – again – encourage you to discuss the lightheadedness with a doctor.
Best wishes,
Mario
From my understanding on hypoglycemia, based on the research I’ve read as a non-specialist: the symptoms of hypoglycemia are actually symptoms of the body’s counterregulatory response to dropping blood glucose, which includes increasing cortisol/epinephrine hormone levels and activating the sympathetic neural system.
In people with diabetes who frequently experience medication- or insulin-induced hypoglycemia, the body’s “set point” for when to trigger that hormonal response changes over time, getting set lower and lower until it results in “hypoglycemia unawareness,” a condition in which clinical hypoglycemia does not result in any of the symptoms we associate with it, such as lightheadedness, sweating, hunger, tremors, palpitations, etc. Conversely, in people with untreated diabetes who have consistently elevated hyperglycemia, the body’s set point gets set progressively higher and higher over time, resulting in hypoglycemia-like symptoms even though clinical hypoglycemia is not actually occurring. For both of these conditions (hypoglycemia unawareness and false hypoglycemia) the treatment is achieving improved normoglycemia with fewer excursions below or above the recommended range in order to change the set point at which those symptoms are triggered.
Please keep in mind I am not a medical professional and this is just my lay understanding of how it generally works, not what you are personally experiencing, so as Mario said — a doctor would have actual advice for your specific situation.