I spend most of my working hours writing about why diets don’t work. I think it’s helpful for people to learn the truth about these diets and “lifestyle changes” that promote themselves as life-changing but are actually harmful. But after a while, it’s hard not to feel like I’m writing the same story over and over. It’s like an anti-diet mad lib. Various diets and food rules get swapped in and out, but the framework is always the same. (Ironically, diets themselves do exactly the same thing.)

This post originally appeared in my weekly newsletter, where I answer reader questions about intuitive eating, Health at Every Size, and how to live your anti-diet values.

Intentionally trying to change your hard-wired behaviors around food is certain to backfire. It doesn’t matter if you’re trying to eliminate a food group, avoid eating outside a certain time window, or limit yourself to a predetermined amount of each macronutrient every day. Weight loss is not sustainable, and all diets ultimately fail. And, you’ll likely end up feeling even more out-of-control and obsessed with food. Here, I’ll get into the specifics of why diets don’t work, and how you can work towards food peace and better health without them.

Diet failure statistics show that weight loss isn’t realistic

Before we get into exactly why diets don’t work, let’s look at the evidence. Countless studies over the years have looked at weight loss statistics, and virtually all of them conclude that long-term weight loss is impossible.

A 2007 study published in American Psychologist found that while many people lose weight initially on diets, almost of them gain the weight back within a few years. Many even regain more weight than they lost.

A 2020 study published in The BMJ found that dieters on all kinds of popular diets lost weight and had improved health markers (lower blood pressure, lower LDL cholesterol, less C reactive protein) after six months. But, the weight loss and the health improvements disappeared after 12 months. People regained the weight and their health markers went back to where they started.

A 2013 review published in Social and Personality Psychology Compass came to the same conclusions. Although diet programs lead to short-term weight loss, they’re almost never effective in the long term. Most people will regain any weight they lose by dieting. 

A 2011 review in Nutrition Journal  found that dieting can actually lead to weight gain. And, many dieters experience other nasty side effects like food obsession, lowered self-esteem, and disordered eating behaviors.

Why diets don’t work — the binge-restrict cycle

Part of the reason diets don’t work is that they lead to food obsession — intense cravings for foods that we can’t eat. This ultimately leads to the restrict-binge cycle. When you start restricting, you feel great. But soon, you start to feel obsessed with food, constantly craving it and always thinking about it. Eventually, you give into these cravings. Because you’ve been restricting, you feel out of control when you start eating the foods you’ve been craving. Ultimately, you binge. This leads to shame, which leads you right back to restriction.

The truth is that you can’t permanently reprogram your eating habits. The vast majority of people can’t sustain restrictive diets. This leads to yo-yo dieting (trying diet after diet, always regaining the weight in between) and even more frustration.

Why weight loss isn’t sustainable

Even if you somehow manage to avoid the binge restrict cycle, your body will resist weight loss long-term. A 2015 review in the International Journal of Obesity explains that your body will adapt to resist weight loss in every way possible. It will start burning fewer calories in an attempt to conserve energy. It will oxidize (AKA burn) less fat for energy. Your glands will secrete less leptin (a hormone that signals fullness) and more ghrelin (a hormone that signals hunger). Basically, you’ll burn fewer calories doing the same activities, and you’ll always feel hungry.

Weight is not an indicator of health — it’s possible to be healthy at any weight

Accepting the fact that weight loss isn’t realistic can be tricky (more on that in the next section). But the good news is that giving up your pursuit of weight loss doesn’t mean that you can’t be healthy. The Health at Every Size® (HAES) movement is centered around the fact that it’s possible to pursue health without pursing weight loss. In fact, evidence shows that it’s easier to adopt healthy habits (eating nutritious food, moving your body, stressing less) when you’re not trying to lose weight.

A 2002 clinical trial published in the International Journal of Obesity and Related Medical Disorders assigned women to one of two groups. One group focused on improving healthy habits without trying to lose weight. The other group focused on dieting for weight loss. At the end of the study, the women who weren’t trying to lose weight ended up improving their health (measured by diet quality, mental health, and metabolic health markers) far more than the women who were on a diet.

And, the science is clear that is is possible to be healthy at higher weights, just as it’s possible to be unhealthy at lower weights. A 2016 study published in the Journal of the American Medical Association found that adults in the “overweight” BMI category lived longer than those in any other category. And, that those in the “underweight” had the highest risk of mortality.

Why it’s hard to accept the fact that diets don’t work

Unfortunately, we live in a culture that worships thinness and discriminates against people in larger bodies. Even if you understand that diets don’t work and weight loss isn’t necessary, it can be hard to accept your body. If you’re working towards body acceptance, you can find some actionable advice here.

Another way of thinking about body acceptance is the process of grieving the thin ideal. Food and body peace coach Meredith Noble writes an excellent post about why this grief process can be so helpful.

First, there’s denial. When you learn about the fact that diets don’t work, you might resist the truth.

Then, you get angry. You’re furious that you’ve been misled for so long. Not only are you angry that weight loss is impossible; you’re also angry you’ve been told that it’s possible.

You start bargaining. Perhaps you think to yourself, “OK, I’ll accept all of this as soon as I lose a little weight!”

Eventually, you feel depressed. The depression phase is when the truth really starts to sink in. You realize that you’ll never have an “ideal” body. If you live in a fat body, you must come to terms with the fact that your body may never be deemed “acceptable.”

Finally, you arrive at acceptance. This is when you can really start living your life on your own terms. You accept that diets don’t work, and you stop trying to lose weight. It’s scary, but it’s also liberating. You’re able to adopt healthier habits without hoping they’ll change your body. And because you don’t have unrealistic goals, these healthy habits actually feel good!

Why intuitive eating is the only way to find true food peace

Intuitive eating goes hand-in-hand with a weight-inclusive HAES approach. In order to be a true intuitive eater, you must reject the diet mentality (for all the reasons above.) You must learn to accept and respect your body as it is, which means grieving the thin ideal.

Once you’ve learned to accept your body, you can start making peace with food by tuning into your hunger cues. This means challenging honoring your hunger and challenging your inner food police. Ultimately, doing this will end your food obsession and heal your relationship with food.

The bottom line is that dieting doesn’t lead to weight loss. Whether you’re on a crazy fad diet or you’re just trying to eat less, your attempts will backfire.