Can dieting actually lead to long-term weight loss?
Dieting has long been seen as the path to smaller bodies and better health. Stick to the right diet, the $75 billion US weight loss industry you might think, and you too can lose weight and keep it off.
The rise of new weight loss drugs like Wegovy and Zepbound has highlighted just how ineffective dieting has been for the millions of people who have tried it. In a 2021 Clinical Trial For example, with semaglutide (the active ingredient in Wegovy), those taking the drug lost about 15 percent of their body weight in just over a year, while those relying on diet and exercise alone lost only about 2 percent.
But there are many people who want to lose a few pounds for whom weight loss medications are not the right choice. Is old-fashioned dieting a good option for those people?
We asked some experts to explain what a diet can and cannot do for you.
Can a diet help you lose weight?
In the short term, diets seem to help most people lose at least a small amount of weight, whether it’s a low-fat or low-carb diet or simply calorie restriction, says Dr. Ellen Schur, director of the University of Washington Nutrition and Obesity Research Center.
But individual results may vary. In a 2018 clinical trialFor example, researchers asked 600 people to follow a low-fat or low-carb diet for a year. While most participants lost weight — an average of 5 to 6 percent of their body weight (or 12 to 13 pounds) — about 15 percent gained weight during the study, and a few lost as much as 50 to 60 pounds.
However, it’s common for people’s weight loss to reach a plateau around six to eight months, after which they are at risk of regaining that weight, said Dr. Maria Collazo-Clavell, an endocrinologist at the Mayo Clinic. Research shows that most people return to their previous weight within about four years.
For those who manage to keep the weight off, it’s not clear whether this is due to their genetics, health history or simply their life circumstances, such as having a supportive partner, a steady job or time to cook, says Kevin Hall, a nutritionist. and metabolism scientist at the National Institutes of Health.
Why doesn’t the weight stay off?
When you lose weight, your body responds by increasing your appetite and decreasing the number of calories you burn, said Dr. Hall.
Him and others have estimated that for every two pounds of weight you lose, you metabolism slows down by about 25 calories per day, and your… pull increases by about 95 calories per day. In other words, if you lose 20 pounds, your body will burn about 250 fewer calories each day while craving about 950 more calories.
To maintain your weight loss through dieting over time, you’ll have to continue eating less while resisting increasing appetite and a slower metabolism, which “becomes more and more difficult,” said Dr. Barn.
The urge to eat more is so strong because our brains “sense that our energy stores are being depleted,” she added, and “that’s a threat to our survival.”
The new weight loss drugs prevent weight gain in part by reducing normal appetite signals, said Dr. Collazo-Clavell. But when people stop taking the drugs, the weight returns, probably for the same reasons described above.
Are there any health risks associated with dieting to lose weight?
Dieting often results in cycles of weight loss and recovery, and some research has suggested this can be harmful, says Kendrin Sonneville, associate professor of nutritional sciences at the University of Michigan School of Public Health.
Some, but Not everythingResearch has shown that there are weight fluctuations die earlier, cardiovascular disease, Type 2 diabetes And depression; However, these studies sometimes include people who have lost and regained weight due to health problems, not just diet.
“There is no conclusive evidence that going up and down is harmful,” said Dr. Schur, but there is discussion about the possibility.
Dr. Sonneville also worries that dieting could put some people at risk of developing an eating disorder. Anecdotally, many people with eating disorders say their condition started with dieting, she said. While clinical weight loss studies have not confirmed this, these studies have had many limitations and have not fully assessed how diet affects people’s relationship with food and their bodies in the long term, said Dr. Sonneville, so more research is needed.
Most dieters don’t develop an eating disorder, Dr. Sonneville said, but even then their relationship with food can worsen if they “start prioritizing weight and nutrition over joy, culture and connection.”
If you have a difficult relationship with food and your body, or if you’ve had binge eating or another eating disorder, Dr. Schur said, it’s more important to focus on a healthy relationship with food than on your weight.
If dieting doesn’t work, what should we do?
People sometimes think that if they just “grit their teeth and roll with their fists” on a diet to lose 10 or 20 pounds, “they can start to relax,” said Dr. Hall. “That’s the wrong way to think about it.”
If you want to change the way you eat to lose weight, you need to maintain those changes “for the rest of your life,” he said. “Otherwise you’ll put the weight back on.” So consider making healthy changes that you can stick to, he said.
If you consume a lot of ultra-processed foods, reducing your intake may be a sustainable approach. Short-term research has shown that those who consume primarily ultra-processed foods tend to eat more and gain more weight than those who consume minimally processed foods, although Dr. Hall acknowledged that a lack of time, money and access to whole foods are all potential barriers to making this change.
Dr. Collazo-Clavell suggested adopting a Mediterranean diet, which focuses on healthy fats, whole grains, legumes, nuts, fruits and vegetables. Taking the time to eat at least two or three meals every day can help you feel full and be less likely to overeat at the end of the day, she added. And avoid eating within three hours of going to bed, which has been linked to weight gain.
Regular exercise can also help maintain weight and has many other benefits, including longer life and a lower risk of dementia, said Dr. Barn.
Ayana Habtemariam, a dietitian in Arlington, Virginia, encourages her clients—many of whom have been dieting for decades—to eat intuitively. This involves tuning in more deeply to your body’s signals of hunger and fullness, and redefining success so you can feel happy and confident no matter your size, she said.
All the experts we spoke to agreed on one point: People will benefit from adopting healthy habits, “even if they don’t lose a pound,” said Dr. Collazo-Clavell.