SOEL Chapter 2: Why Diets Don't Work...
Friday, December 13, 2019
Chapter 2: Why Diets Don’t Work: Biology, Stress, and Forbidden Fruit
Circumstances determine how people behave, that is following a set of unspoken rules. Example, in a classroom, students will raise their hand and wait to be called upon before they speak.
To keep weight off, circumstances can be against you:
1. Environment of near-constant temptation
2. Biology – body’s evolved response to starvation, meaning when dieting you eat less calories even though food is available. In survival times of scarcity, genes were passed on to future generations so that one could get by on small amounts of food.
3. Single-minded pursuit of food and once found there is an overwhelming urge to eat lots of it.
Genes play an important role in how much you weigh throughout your life: body type and weight range that you can healthily maintain. Your body stays in that range most of your adult life.
Study of identical twins, which were raised apart, had similar body weight. Conclusion of the study is that genes account for 70% of the variation in people’s weight and 80% is the genetic role for height. The author’s idea is your influence on how much you weight is limited because you have a genetically determined weight range.
There was a study to have people gain weight and then try to maintain that weight. This study was first done on prisoners, then on volunteers. They found they were unable to turn them into obese weight. However, this study was only done for 100 days.
(My note: apparently this is not true over that 100 day mark; my weight gain came after 3 months of not caring what I ate.) The author’s point is that genes control how much weight we gain. Participants were fed the same amount of food, but the weight gained among the participants varied.
Your body tries to keep you at a particular weight range. When you are within that weight range, you don’t have to struggle to it there. The struggle begins once you get out of that weight range.
Your brain signals change when you are dieting and hungry. The active part of your brain responds differently to food than when you are not dieting. When dieting, you notice food more, pay more attention to it when you find it, food will look more delicious and tempting than usual, which are all signals to eat.
At the same time, there are changes in the brain that have reduced activity in the prefrontal cortex, which has the “executive function”, the part of the brain that helps you make decisions and resists impulses.
So, one part of the brain will become more active and the other has reduced activity, either one makes it more likely for you to indulge. However, put them together and you don’t stand a chance to resist temptation. “Your ability to resist is taking a snooze exactly when you most want its support.” (p.22) This response becomes stronger the longer you diet.
The body also defends your weight range through hormones. Fat, also known as adipose tissue, is part of the endocrine system that produces hormones involved in sensations of hunger and fullness. When you lose fat, then the amount of those hormones circulating in your body will change.
Hormones to help you feel full that decrease when dieting and feeling hungry, (including, peptin, peptide YY, cholecystokinin). In addition, the hormones that cause you to feel hungry increase, (including ghrelin, gastric inhibitory polypeptide, and pancreatic polypeptide). Just as changes in brain patterns, the hormonal changes also give you an urge to eat and to eat a lot. One study seemed to indicate that these changes were still detectable one year after dieting.
So, we can see that changes in the way the brain reacts and hormone production can push you to eat more; your metabolism is another thing that can work against you. Your body takes energy just to keep you alive. This is true whether you are on a diet or not. The more you weigh the more energy (calories) you burn.
And even if starvation has no effect on your metabolism, when you lose weight your body will burn fewer calories. This means that eventually the number of calories you are eating while on your diet may eventually become too many calories if you want to continue to lose weight.
But, often when we do diet (diet here is being defined as eating reduced-calorie), your body does not get sufficient calories and thinks that it is being starved. This will effect on your metabolism. When you do not eat enough, your metabolism will slow down to conserve energy. When your metabolism slows down (burns less calories) this does nothing to help you feel full or to help you lose weight. In fact, it has the opposite effect. It begins to use each calorie more efficiently so that the number of calories your diet has you eating becomes too many. Because you are now needing less calories for your body to just keep you alive, any more calories than that will be considered extra and can be stored as fat.
The problem here is that the body will make it a priority to store foods you eat, even non fatty foods, as fat. That means to continue to lose weight you will need to eat even less calories. In other words, you lose weight and now it will take fewer calories for you to maintain that weight. This is why you often gain weight when dieting.
Too often, when you go on a diet, lose weight and then begin to gain weight again, sometimes it is easy to blame self-control. But as we have seen, it is not all about self-control; it is also about:
1. Evolution – your genes
2. Biology – hormones
3. Brain patterns
The point the author is trying to make in this chapter is that in order to lose and maintain the weight loss, all systems seems to be working against you and it is not really about how much self-control you have. (my opinion here: I think this is referring to if you are continuing to stay on the diet’s calorie plan and not if you go off and eat what ever.)
Back in the 1940’s Ansel Keys did a 6 month study, where 36 men volunteered to be starved for 6 months as a humanitarian act so that the researchers could find out the best way to help those throughout the world that were starving. This study has been referred to as a starvation or semi-starvation study, but the men were allowed nearly 1,600 calories a diet –seems more like a diet study
While doing this study the researchers found there was a psychological change and they recorded how many times the subjects thought of food. In fact, their conversation became about food. They dreamt about food. They thought of favorite meals they enjoyed in the past, or what meals they’d like to have some day. They lost interest in things that did not relate to food.
This behavior may have been useful in times of our evolution, meaning if they were in lean times and always and only thought of food, then that behavior may have been more successful in getting access to food. Today, when we diet and start to focus on food, food and more food we are told to distract ourselves so we don’t go off our diet and eat more than our diet plan prescribes.
The author decided to find out what would happen if people were told that one food was forbidden. She asked her students to participate and they recruited their friends. They were asked to record whenever they thought of this food for 3 weeks. One week they were told they were forbidden to eat that food and those in the study thought of that food more than the other weeks. An example of this is from the Bible with the story of Adam and Eve – they were told they good eat freely of all, except for the fruit of the tree of knowledge of good and evil. And we all know what happened from that.
Another thing that causes us to gain weight is stress. Everyday life = stress. “When psychologists talk about stress, we are referring to a negative emotional response that leads to a specific set of physical , cognitive, and behavioral changes. “ (p. 26) This is often referred to a the fight or flight response to help us deal with situations. This is stress that comes on suddenly and is not the everyday stresses that we face and is happening on a daily basis.
A physical change that happens is the release of the hormone cortisol, which is linked to the storage of belly fat. This hormone helps make glucose available in the bloodstream to give us energy needed to ‘flee from danger’. If we don’t use it, it will get stored as belly fat.
Stress causes some people to act in many ways that cause weight gain, i.e. overeat, exercise less, and sleep less. When you are sleep deprived, your brain responds much the same way as when you are hungry. When you are tired, food will look more enticing to you than when you are rested.
Does dieting cause stress? A study was done to find out. There are 2 rules to follow when you go on a diet:
1. Restrict what you eat
2. Monitor your food intake
This results in:
a) You cannot always eat what you want to eat
b) You monitor your food intake; track what you eat, monitor your eating, count calories and you have to plan your meals.
The study was divided into groups:
1. Restrict eating to 1,200 calories using prepackaged food, no monitoring
2. Restrict eating to 1,200 calories and have to keep a food diary
3. Keep a food diary and not monitor (see above for definition of monitoring)
4. Don’t do any of the above
The person who did the study monitored the cortisol in the dieters’ saliva. What she found was that those was that just the act of restricting calories led to a higher cortisol level (had a physiological stress response).
Conclusion is that dieting causes us stress. Often we are told to try to avoid stress, but here we learn that stress cannot be avoided when dieting because dieting causes stress.
But, let’s not forget about the set weight range, it can be good news or bad. If we have a set genetic range and lose so much weight that we fall below it, we will gain the weight back. But the good side of this is that if we go above our set weight range, it is hard to maintain that weight gain (unless you continue to overeat for a long time.
How do we determine our set weight range? We need to determine what weight we are at if we do not diet nor do we engage in extreme overeating. It is that particular weight you come back to after you have made changes in either direction. Note: “One expert says that you can comfortably lose fifteen pounds below your set point before your body starts trying to defend a higher weight.” (p. 30) That is assuming you have enough weight to lose. This works the same on the high end, which means your set range reasonably covers about 30 pounds (p. 31)
Traci Mann’s advice is to find you set range and try to stay within that range. A healthy goal is to lose some weight but stay within your set weight range. Our aim should be to live at the low end of our set weight range.
Recall, the whole point of this book is that our inability to control our self is not the cause of our weight gain. Traci Man is out to set the record straight that willpower is not the key to weight control. More to come…