Diets don’t work. Restricting food intake may initially lead to weight loss, yet 95% of people who lose weight gain it back within 3-5 years.
Most of us would blame our lack of willpower, but dieting is not a matter of self-discipline.
Consider: how many different diets have you followed? How many times have you reduced your calories; fasted; or avoided whole food groups such as the currently demonised carbohydrates? If any of these diets worked, we would only need one.
Dieting becomes increasingly ineffective every time we embark upon a new nutrition plan. The irony is that intentional weight loss methods actually teach our bodies how to gain weight.
REASON WHY DIETS DON’T WORK #1: PHYSICAL RESTRICTION
Restricting calories or excluding food groups essentially puts our bodies into a state of starvation or malnutrition. Our bodies therefore respond as if there is a famine and make physiological adaptations to keep us alive.
These adaptations include increasing hunger and cravings which lead us to seek out and eat more food, especially those high in carbohydrates. This is owing to hormonal changes brought about by the period of starvation: when it is energy deprived, the brain increases production of the chemical Neuropeptide Y which drives us to consume energy dense carbohydrates.
In addition, reducing body fat through dieting leads to decreased levels of the hormone leptin, which helps us to feel full. Under normal circumstances fat stores release leptin into the bloodstream which informs the body that energy stores are available and signals us to eat less. As we lose body fat, however, leptin levels fall. This leads to increased appetite, particularly for sweet, high energy foods.
Constant restriction of calorie intake by dieting also lowers our metabolism: this is a physical adaptation that ensures we will be able to survive on a smaller amount of food. The more body weight we lose, the fewer calories we need to consume, therefore we need to restrict more and more as weight loss continues.
Our bodies also increase our set point weight as insurance against future famine. This set point is a genetically determined range of 10-15lbs where our bodies are most comfortable. If we drop under our set point weight by restricting food, the body responds and works like a thermostat to adjust metabolism and hormone levels until our weight returns to this stable point.
If we repeatedly engage in dieting, we can actually push our set point weight up. This is because the body’s metabolic condition changes when we restrict our food intake. We cannot lower your set point weight, but it is possible to raise it…by dieting.
REASON WHY DIETS DON’T WORK #2: MENTAL RESTRICTION
Mental restriction such as implementing food rules, categorising foods as ‘good’ or ‘bad’, and forbidding foods that we enjoy such as pizza or chocolate also leads to weight gain.
This is because depriving ourselves of these foods drives up cravings and therefore we end up overeating the very foods we are trying to avoid. Likewise, if we resolve to start a new diet tomorrow, then today we will probably go into ‘last supper mode’ and frantically eat everything in sight because this is our last chance before the food restrictions are in place.
Only permitting ourselves a certain amount of daily calories may also cause the number on the scale to creep up. This is because when we restrict our food intake, we are telling our brains that there is no more food.
This causes the brain to panic and consequently increase our urge to overeat or binge. In this way, we up eating more calories overall than if we hadn’t restricted our daily intake in the first place.
Our body’s responses to physical and mental restriction are survival mechanisms that lead us to eat, and eat a lot. Afterwards, we may experience guilt or shame and resolve to diet even harder. This only serves to perpetuate the binge / restrict cycle, and each time we go through it the restriction becomes tighter and the binges become more extreme.
This constant cycling (or yo yo dieting) places the body in a chronic state of stress. The body reacts to this stress in several ways, one of which is that the adrenal glands produce the hormone cortisol. Cortisol increases appetite and causes cravings for sugary foods, which are then stored as fat.
The fundamental message is that we cannot control our weight long term. It is impossible to sustainably fight against our biological instincts. It’s just like breathing: we can hold our breath for a little while, but at some point, we are going to have to breathe.
We need to reject the diet mentality and throw away our meal plans. If we truly allow ourselves to eat without deprivation or restriction, the drive to seek out excessive amounts of food subsides as our bodies and brains learn that the famine is finally over.
We need to embrace food freedom, allow ourselves all foods, and trust that our bodies know what to do.