Dieting is Dangerous: What Neuroscience and Evolution Teach!


Only 1% of dieters will maintain the new weight without regaining what they lost by losing weight. This means that only 1 in 100 people who diet will have long-term success. These numbers get even more frightening when it comes to morbid obesity: only 1 in 1290 extremely obese men will maintain weight loss and only 1 in 677 women with morbid obesity. You know what’s the problem? It’s not little or no willpower, but the way our brain works. What evolution and neuroscience teach us is that focusing on diet to lose weight is a huge mistake. In addition to not guaranteeing weight loss, on the contrary, the diet is almost never accompanied by significant improvements in health.

Every time you start a diet, your brain will NOT understand that you want to lose weight, on the contrary, it will think you are hungry and will trigger an alert state, looking for ways to not lose weight, either by making you not resist diet or consuming less calories from the food eaten. And if you lose weight your brain won’t forget the weight before and sooner or later you’ll get back to the weight your brain wants which is the unwanted weight by yourself. It doesn’t matter if the weight loss occurred quickly or slowly, in months or years your weight returns to the weight before you went to bed – worse! – 41% of people start to have more weight than the weight they had before the diet. Spooky?

So what’s the solution? The focus cannot be on food but on activities that take the focus off food. What are they? Exercise and meditation. These are activities that can change the way your brain works. The truth is that the simple fact of going on a diet greatly increases the chance of becoming obese one day: it increases 2 times for men and 3 times for women, all you have to do is go on a diet. Women who have had 2 or more diets in their lifetime are 5 times more likely to be overweight. Sad isn’t it? A study of identical twins shows us that the dieting twin is more likely to become obese compared to the non-dieting twin. The difference in the propensity to gain weight is even greater when it comes to fraternal twins, which suggests (in addition to many other studies) a very expressive genetic component in the tendency to gain weight or enter the obesity statistics. Athletes who diet to qualify for competitions such as boxers and wrestlers are 3 times more likely to become obese by the time they reach 60 than athletes who don’t need to diet.

Some programs to fight eating disorders aim the opposite: to teach people and especially teenagers not to focus on weight, not to want to be thinner and not to go on diets. Among them, the eBody Project and the Tri Delta – Fat Talk Free. In these programs, teenagers end up gaining less weight than girls in the same conditions that go on a diet. Again: the focus cannot be the regime! But why? Because dieting is stressful, and stress creates an accumulation of abdominal fat, which in turn is related to health problems such as diabetes and cardiovascular disease. In addition, being on a diet creates more anxiety, which in turn increases the person’s chance of acquiring compulsive eating habits in the future. Adolescents who frequently diet are 12 times more likely to have binge eating in subsequent years.

Binge eating is a natural response after periods of exacerbated hunger. Our brain does not understand the diet as a desire to starve to lose weight, but rather as a period where hunger is a consequence of lack of food. Apparently, this is a common response to most mammals that have faced many periods of hunger over the last few million years, but especially for us humans who, when we invented agriculture, started to have less variety in food and to face periods of famine due to natural disasters that destroyed future crops were more frequent. Today, brains that indulge in binge eating are waiting for a period of scarcity that will never come, and therefore they become obese. Obesity is as new to men’s society as food abundance. Therefore, it is also a novelty for our brains to want to lose weight, refuse an abundance of sugars and fats, as well as not having to wait for hunger.

Diet is synonymous with stress, but not positive stress, but negative stress. Negative stress consumes a lot of glucose, which is the fundamental food of self-control that will have your ability to resist the most reduced temptation. In addition, frequent food deprivation alters dopamine circuits as well as other neurotransmitters in the brain that are responsible for calibrating our satisfaction and dissatisfaction, setting new limits to define hunger and satiety or acceptance and frustration. Laboratory rats acquire compulsive habits after experiencing periods of food deprivation. Rats exposed to the same type of stress but without facing hunger do not give in to the compulsion. In practice, rats that are stressed and hungry will eat Oreo compulsively while rats that are stressed but not hungry will not want to eat Oreo non-stop. So if you don’t want to succumb to a packet of Oreo or a pot of Nutela, the first step is not to diet.

People in general associate weight loss with an improvement in metabolism, when, in fact, this metabolic improvement is caused by behavioral changes, such as physical activity or eating healthy foods (vegetables, fiber, etc.). Dieters stop paying attention to the signs of hunger and satiety and start to practice external rules that do not necessarily benefit the body in question. The regimen generates a vicious cycle that is destructive and generally based on aesthetics. Regular use of weight scales is related to the development of eating disorders. Children who witness their mother’s diet are more likely to be obese or have cravings or other eating disorders. Anyway, dieting is dangerous.


This is a free abstract of the article Why You Can’t Lose Weight on a Diet written by Sandra Aamodt in The New York Times (May 6, 2016) ) and adds the concept that self-control is a limited source of energy (Baumeister et al, 2007) in addition to brushing evolutionary bases of obesity.

Written by Feitosa-Santana

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