You have to give your body what it wants. Constant restriction is unhealthy

I’m the last person to oppose a little indulgence, but I have to point out that this statement includes a pretty big portion of fat logic.

Proponents of ‘intuitive eating’ often claim that our bodies ‘know’ intuitively what they need — for example, if you feel the need to eat chocolate, that’s because it contains some nutrient that your body currently requires. There may very well be some people out there who intuitively eat a healthy diet, but that doesn’t take away from the fact that our bodies have evolved with a preference for sweet and fatty foods — that is, those with highest possible calorie content.

In the ancient past, when food was generally less abundant and there were no industrially processed products, that preference for sweet and fatty foods was a useful strategy. The foodstuffs with the highest calorie count were nuts, oily fish, or fatty meat, but they had to be laboriously gathered, caught, or killed. From an evolutionary point of view, it made good sense to develop a strong (taste) incentive to eat these foods as a source of important nutrients, rather than spending the entire day munching on masses of vegetables and berries.

Because of this, if our bodies got their way, we would almost always prefer a greasy burger or a bar of chocolate over a carrot or an apple. So, for someone who already has unbalanced eating habits and is therefore under- or overweight (or someone of normal weight with an unhealthy diet), ‘intuitive eating’ is comparable to ‘intuitive drinking’ in an alcoholic. The body’s signals have long since become confused, and alcoholics do experience the physical feeling that they need alcohol, becoming restless with cravings, and even experiencing withdrawal symptoms like shaking, when they don’t get a drink. Their bodies are so strongly habituated to the substance that their system has adapted to it. In a similar way, our system also adapts to an unhealthy diet over time, for example with changes in our gut flora.

When this happens, the body has to be consciously retrained so as to eventually regain a healthy intuition after some months or years.

I think the idea that intuitive eating is healthier is based on an inverted cause-and-effect relation: on average, people who have never had problems with their weight or their health are substantially more likely to eat intuitively than those who have, or have had, difficulties. Most people who have reached an unhealthy state (in terms of body weight or other problems) through intuitive eating, will at some point try to remedy the situation by taking countermeasures (dieting, nutrition plans, calorie counting), which means they can no longer be considered intuitive eaters.

To say that eating a calorie-controlled diet is bad is like saying that frequent visits to the doctor are bad because people who go to the doctors a lot are ill more often. But you don’t get sick from sitting in the doctor’s waiting room; you sit in the waiting room because you’re sick. It would be daft to tell someone with a serious illness not to see their doctor because there is a connection between visiting the doctor and sickness.

Concerning the claim that ‘restriction is always bad’: it’s now been known for more than 70 years that long-term caloric restriction increases longevity in various animal species like rats, mice, hamsters, dogs, and fish. Caloric restriction slows down the ageing process and guards against chronic disease in old age. This doesn’t appear to be a result of reduction in body fat, but of the caloric restriction itself (Masoro, 2005).

Carrillo & Flouris (2011) assume caloric restriction lowers body temperature, which has a positive effect on longevity because, among other things, it influences hormone regulation and prevents inflammation. The mechanisms by which caloric restriction slows down the ageing process are not yet sufficiently understood. But it does seem clear that both a lower proportion of body fat and restricted caloric intake have a direct, positive effect on physical health and longevity.