3 disruptions causing overeating, leading to obesity and weight gain, and what we can do about it. Referenced from 5 books

Posted Sep 16, 2024

By Nandu Dharmapalan 21 min read

Introduction

Disclaimer: I am not a medical professional or a scientist. I am sharing what I learned from the books discussed here and how I make sense of them. It may or may not be accurate. This article is for informational purposes only and is not a substitute for professional medical advice. Please consult with your medical practitioner for medical advice, care etc.

This article discusses obesity and weight gain through three disruptions that cause overeating. It is referenced from five books. A short summary of these disruptions or other topics related to obesity and weight gain from these books are shared here. Now let’s look at some of the causes of obesity and weight gain, and what we can do about it.

What causes obesity and weight gain?

To answer this question, this article references the book “Burn by Herman Pontzer PhD”. The author of the book researches metabolism and health and the book is about that. Now let’s look at some of the topics in the book relevant to obesity and weight gain. Our body derives energy from carbohydrates, fats and proteins contained in the foods and drinks we consume. If we consume more than what we need then it is converted to stored energy such as glycogen or fat. If we consume less than what we need then we use our stored energy, that is, if it’s available. Our body has mechanisms to regulate the intake of food and manage energy expenditure to keep this accumulation and depletion of stored energy in a balanced state. For example by controlling hunger or changing the allocation of energy to say our immune system. When this mechanism is working well, our weight remains stable. When there are disruptions to the mechanisms that manage intake then we could end up eating more than what we need to. If we eat more than what we need, we gain fat. If this process continues for a period of time then it could lead to gaining of a lot of weight which results in obesity. In short overeating can lead to obesity and weight gain and overeating can be due to disruptions to some of the control mechanisms in our body.

Please note that there could be reasons other than overeating resulting in us gaining weight and becoming obese. The information shared here is limited to what I understood from the books referenced. The next section discusses some of the disruptions that make us overeat.

Why do we overeat?

We are going to look at this through discussions contained in the books, that we are going to reference, about mechanisms affecting hunger. From these books this article discusses three disruptions to our body affecting its ability to manage hunger. These three disruptions are due to protein leverage, insulin resistance and the activation of the survival switch. We will discuss each of these in more detail in the following sections.

Protein leverage

Protein leverage is a concept discussed in the book “Eat Like The Animals by David Raubenheimer, Stephen J. Simpson”. The authors of the book are researchers and their research shows that we have separate appetites for different nutrients such as proteins, carbohydrates, fats, sodium or calcium. These separate appetites guide us to fulfil our nutrient requirements. When we have equal access to the nutrients we need these appetites work together and guide us into eating in a balanced way. The result is that on average we eat what we need of each nutrient and not more. This process is thrown out of balance when there is limited access to nutrients. In such cases our separate appetites compete with each other and our appetite for protein wins. For example if we have limited access to protein rich foods then our protein appetite drives us to eat more of the available low protein foods to fulfil our protein requirements. Eating more of the low protein foods makes us eat more carbohydrates and fats since if low on protein they must be high in either carbohydrates or fats. This overshoots our carbohydrate or fat intake compared to what our carbohydrate and fat appetites alone would have determined as ideal. The opposite is also true. If what we have access to is just protein rich foods then we under consume carbohydrates and fats. This again is our protein appetite dominating and driving us to reduce our consumption or stop eating as our protein requirements are met, even though our carbohydrate or fat requirements are not fully met. One thing to note is that this power of our protein appetite to drive hunger is diminished when we have eaten enough fiber. To summarize our body prioritizes meeting our protein requirements over carbohydrate or fat requirements when the availability of these nutrients are not balanced. Consuming a low protein diet makes us overeat the low protein foods thereby increasing the consumption of carbohydrates and fats which result in an over consumption of carbohydrates and fats or calories.

As an example to demonstrate this let’s say a person has a protein requirement of 30 grams and a carbohydrate requirement of 500 calories. The person has access to either hard boiled eggs or muffins. One hard boiled egg contains 6 grams of protein and 77 calories. 100 grams of muffins contain 5 grams of protein and 410 calories.

If the person eats five eggs, the person gets 30 grams(5 eggs* 6 grams) of protein and 385 calories. In this case the energy requirement of 500 calories is not met but protein requirements are met. Since protein appetite takes precedence over carbohydrate appetite, the body dials down hunger. The person feels full even with the under consumption of calories.

If the person chooses muffins, the person’s carbohydrate requirements of 500 calories would be met with approximately 120 grams of muffins. When that happens carbohydrate appetite would be signalling that the carbohydrate requirements are met but since the protein appetite takes precedence and the protein requirements are not met, the person would still remain hungry. The persons eats 600 grams of muffins and gets 30 grams of protein and 2460 calories. Now that the protein requirements are met the person feels full, but in this process the person overate calories by a significant amount(500 calories required vs 2460 calories consumed). This demonstrates how protein leverage results in over consumption of calories.

In short, protein leverage is a mechanism by which our body manages our food intake. If there is less than ideal amounts of protein in the foods we eat then our body makes us overeat the foods to fulfil our protein requirements.

Note: The values of nutrients contained is taken from United States Department of Agriculture website and is approximated for easier calculation.

Insulin resistance

The topic of insulin resistance is going to be referenced from the book “Why We Get Sick by Benjamin Bikman PhD”. The author is a researcher and one of his research focus is on insulin, its relationship with metabolism and the the problems associated with insulin resistance. The hormone insulin is primarily involved in glucose control in the blood. Our body or specific organs could develop a resistance to its effects. This is called insulin resistance. To give an example let’s say normally our body need 10 units of insulin to shuttle 10 grams of glucose from the blood into our cells, thereby clearing it out of the bloodstream. If our body develop insulin resistance we need more, say 15 units of insulin to shuttle the same 10 grams of insulin out of the blood. Or 15 units of insulin is needed in an insulin resistant state to do the same job as what 10 unit of insulin normally did. In short insulin resistance is a condition in which our body needs more insulin than normal to get the same response as before. Now we will see how this relates to overeating.

Insulin resistance leads to various problems, one of which is leptin resistance. Leptin is a hormone involved in appetite control. Normally when leptin levels are high our body gets the signal that we have enough energy and we need to stop or reduce our food intake. As a result we may become less hungry or fell full. Leptin resistance occurs when our body doesn’t respond to leptin like it normally did. With leptin resistance high leptin levels doesn’t make us less hungry or make us feel full. In other words leptin resistance leads to an impairment in our bodies mechanism to control hunger. To summarize insulin resistance leads to leptin resistance, which leads to an inability to manage hunger and it can lead to overeating.

The activation of the survival switch

This topic is going to be referenced from the book “Nature Wants Us to Be Fat by Richard J. Johnson, MD (Author), David Perlmutter, MD (Foreword)”. The author is a researcher. His research shows that animals have a biological response to threats to survival such as starvation, dehydration or suffocation, which is called a survival switch. An activation of the survival switch leads to certain behavioral and biological changes such as stimulation of the foraging behavior for food or water, decreased energy expenditure while at rest or causes leptin resistance in the brain. As we saw in the previous section leptin resistance leads to poor appetite control. In essence these behavioral and biological changes can result in an over consumption of calories and subsequently the build up of fat stores. These stores acts as a defense mechanism against threats to survival, say starvation or severe dehydration. Examples of this behavior include bears preparing for hibernation or birds preparing for long migrations, overeating and building up fat stores. If you are wondering how fat helps with severe dehydration then the answer is that fat when burned for energy releases water as one of its by products. The book notes that this is one of the reasons why a camel stores fat and not water in its hump. It makes use of the water released from the burning of fat from its hump. In short there is a survival mechanism in animals including us which when activated makes us hungry and overeat calories.

Now let’s look at some of the factors that activate the survival switch. The factors we are going to discuss are the over consumption of fructose, over consumption of glucose in a short period of time and the over consumption of umami rich foods.

Consuming a lot of fructose is the dominant mechanism by which the survival switch gets activated. The book notes that the switch is more like a dial and when we have some fructose it gets somewhat dialed up and if we have a lot then it gets dialed up way higher. Anyway a major source of fructose in our diet is added sugars like table sugar or high fructose corn syrup. Table sugar is 50% fructose and 50% glucose. High fructose corn syrup varies in its composition and can be 42% fructose or 55% fructose with the rest being glucose and water.

Consuming a lot of glucose in a short period of time turns on the survival switch as well. The way this works is through our body’s ability to convert glucose into fructose. Conversion of glucose to fructose happens in certain cases in the body. For our discussions we are going to be looking at high glucose concentrations in the blood triggering the conversion of glucose into fructose. In such cases the production of fructose can be high enough to activate the survival switch. The situation of high blood glucose concentrations in the blood would arise when consuming sugar sweetened beverages, fruit juices or from consuming a lot of high glycemic carbohydrates like rice, bread or noodles. Additionally the production of fructose is stimulated by mild dehydration. Mild dehydration can be from not drinking enough water or eating a lot of salt. Hence having heavily salted popcorn with a milk shake stimulates even more fructose production than just a milk shake. Either way the amount of glucose can be high enough to produce the amounts of fructose needed to activate the survival switch.

Consuming lots of foods rich in umami also activates the survival switch. Glutamates is the class of compounds we sense as the taste umami. Mono sodium glutamate or MSG is a form of glutamate. The book discusses studies on mice with MSG added to their drinking water. After a while the mice lost control of their appetite, overeat, gained weight and became obese. This mechanism is probably applicable to us too. Some foods rich in glutamates are beer, MSG added to food or extracts from soy. A search online for foods with MSG returned an article from healthline.com and it says MSG is contained in fast food, chips and snacks, seasoning blends etc.

In summary there is a mechanism in our body which when activated makes us hungry, forage for food, overeat and gain fat. It is called a survival switch. It can be activated by certain factors, three of which are consuming a lot of fructose, consuming a lot of glucose in a short period of time or consuming a lot of umami rich foods. Any of these factors can activate the survival switch which can lead to overeating calories.

Note: I want to mention that I have given more weight to certain topics from certain books in terms of how I evaluated which is the best source for that information. For example when it came to insulin resistance I have referenced the book “Why We Get Sick by Benjamin Bikman PhD” more than other books because the author researches insulin and hence better qualified to talk about the topic. Similarly for topics related to exercise I have given more weight to what is in the book “Burn by Herman Pontzer PhD”. The author researches metabolism and how exercise affect us metabolically so I think he is a better source of information related to those topics.

What can we do to reduce or prevent overeating?

Having discussed the role of protein leverage, insulin resistance and the activation of the survival switch in overeating, let’s look at what we can do to reduce or prevent it.

When it comes to protein leverage, the takeaway from the book “Eat Like The Animals” is either to increase the protein density in our diet or to increase the intake of fiber. When our protein requirements are met our appetite gets suppressed. In other words having foods rich in protein can make us fell full in fewer calories and we could end up eating less carbohydrates or fats than we need. Increasing the intake of fiber helps since when there is enough fiber in our diet the power of protein leverage to drive excess calorie intake reduces. The book has details on how to calculate the amount of protein we need and notes that the amount of protein we need does not stay constant. For example we may need more protein during certain stages of growth or during an infection. The book says that having too much protein is not good too, as it switches on biological processes that cause aging. It is a complex topic and I encourage you to read the book to learn more. Anyway, in summary, having a higher protein density in our diet but not too much and/or eating enough fiber helps to reduce or prevent overeating.

When it comes to insulin resistance, the book “Why We Get Sick by Benjamin Bikman PhD” discusses the causes of insulin resistance and how we can improve or prevent it. Reducing insulin resistance helps with reducing leptin resistance which in turn helps with better appetite control. A summary of the causes of insulin resistance would be that there are three primary causes for insulin resistance. These are too much insulin, stress and inflammation. Any one of these can cause insulin resistance independent of the others. Addressing these root causes help with a reduction or reversal of insulin resistance. Now let’s look at each of these. Too much insulin can be caused by the frequent consumption of foods high in sugars. These can include sugar sweetened beverages, sugary treats, high glycemic carbohydrates etc. The book recommends a low carb or keto diet as well as fasting to reduce insulin levels. Regarding the factors of stress and inflammation there are some lifestyle changes that are recommended. For example for reducing stress, try making improvements in sleep. For reducing inflammation, reduce or stop smoking cigarettes. Addressing any or all of the root causes help in reducing insulin resistance which results in improved leptin sensitivity. It in turn improves appetite control, reduces hunger thereby reducing or preventing overeating.

When it comes to the activation of the survival switch addressing the causes of the activation helps us to reduce hunger and reduce or prevent overeating. It is discussed in detail in the book “Nature Wants Us to Be Fat”. A summary of the main points would be to reduce the consumption of foods rich in fructose, glucose or umami. In the case of fructose this would look like reducing the consumptions of foods that contain a lot of table sugar or high fructose corn syrup. Examples are sugar sweetened beverages, sugary snacks, fruit juices or dry fruits. The book notes that whole fruit has fructose in it but it is difficult to overeat and it’s not only okay to eat whole fruit but also healthy to do so. Fruit juices or dry fruits are an other story though. For example we could feel full eating two or three plums but in its dried form as prunes we could easily consume way more than that. In the case of glucose it is recommended to reduce the consumption of foods rich in glucose like sugar sweetened beverages or high glycemic carbohydrates such as rice or bread. Drinking enough water and limiting foods high in salt like heavily salted french fries or popcorn is recommended as well. For over consumption of foods high in umami the book recommends reducing or eliminating the consumption of beer or limiting foods high in umami such as shellfish. In summary to reduce or prevent overeating reducing the consumption of foods rich in fructose, glucose or glutamates help. Reducing the consumption of these dial down the activation of the survival switch. It results in better appetite control which inturn helps to reduce or prevent overeating.

I want to add to this discussion the lessons from the two books “Burn by Herman Pontzer PhD” and “The Complete Guide to Fasting by Jason Fung MD with Jimmy Moore”.

The book “Burn” is a book on metabolism and discusses the role of exercise in our health in detail. The takeaway for weight loss is that exercise is not an effective tool to lose weight. The book discusses how our body uses energy or our metabolism by using a concept called constrained daily energy expenditure model. The short summary of it is as follows. Our body tightly controls energy expenditure to be within a certain range. When we increase energy expenditure on say exercise our body decreases energy expenditure on other areas like inflammation or reproduction. This balancing act keeps our daily energy expenditure within a short range. Hence regardless of whether we exercise or not our daily energy expenditure stays almost the same, only the allocation of energy to different processes in our body change. There are other reasons to exercise though. Exercise keeps us not only healthy but exercise is an effective way to maintain the weight loss after we manage to lose it. In summary the greatest benefits to appetite control and losing weight comes from changes in diet and/or managing stress or inflammation. The way exercise helps is by keeping us from regaining the lost weight.

The book “The Complete Guide to Fasting” is a guide on how to fast as the name suggests. Almost all the books mentioned here discuss fasting. Fasting has multiple benefits. One of it is that, it is a powerful strategy to reduce insulin levels. Reducing insulin levels helps with reducing insulin resistance. Reducing insulin resistance helps with reducing leptin resistance. Reducing leptin resistance helps with better appetite control. Hence fasting is a powerful strategy for weight loss. This book has a lot of information on how to do it properly and safely. I recommend you check out the book to learn about fasting.

A summary of all the above recommendations to help reduce or prevent overeating would be to reduce or eliminate the consumption of foods rich in fructose or glucose, have enough protein, have enough fiber, stay hydrated, reduce the consumption of salt if’s too high, practice fasting, take steps to manage stress better, take measures to reduce inflammation or reduce the consumption of umami rich foods. It is a lot of recommendations and if I were to guess focusing on the biggest contributors would likely result in the biggest improvements. Anyway improvements in any one of these factors or any combinations of it would probably result in better appetite control and potentially reduce or prevent overeating. If we prevent overeating and eat what we need our weight remains stable. If we eat less than what we eat our body uses our stored energy and we lose weight.

Note: I have given more weight to certain topics from certain books based on how I evaluated which is the best resource for that information. For example regarding insulin resistance I have referred to the book Why We Get Sick because the author researches insulin. Similarly regarding exercise I have referred to the book Burn because the author researches metabolism and how exercise affects us metabolically.

Conclusion

The article discussed the reason for obesity and weight gain through the perspective of overeating referenced from 5 books. Overeating can be caused by problems with our bodies ability to control hunger. Some of the possible causes discussed here are due to protein leverage, insulin resistance and the activation of the survival switch. Solutions to correcting these problems lies in addressing the root causes of these issues. Some of the recommendations from the books on how to achieve that are discussed here but there is more to learn from the books than what is discussed here. I recommend you check out the books to learn more. Additionally it is always a good idea to get the information from the source as there could be errors in translation.

Books discussed

Burn: New Research Blows the Lid Off How We Really Burn Calories, Lose Weight, and Stay Healthy by Herman Pontzer PhD
Eat Like The Animals: What Nature Teaches Us About the Science of Healthy Eating by David Raubenheimer, Stephen J. Simpson
Nature Wants Us to Be Fat: The Surprising Science Behind Why We Gain Weight and How We Can Prevent–and Reverse–It by Richard J. Johnson, MD (Author), David Perlmutter, MD (Foreword)
The Complete Guide to Fasting: Heal Your Body Through Intermittent, Alternate-Day, and Extended Fasting by Jason Fung MD with Jimmy Moore
Why We Get Sick: The Hidden Epidemic at the Root of Most Chronic Disease – and How to Fight It by Benjamin Bikman PhD

Health and Nutrition