Study shocker: Diets might hurt more than they help, says new research

By Julia Ries | Fact-checked by Davi Sherman
Published February 8, 2024

Key Takeaways

  • A new study shows that fad diets promise quick results but often lead to weight cycling and negative impacts on physical and emotional health.

  • Rather than relying on fad diets, prioritize long-term health with balanced eating and self-care practices, avoiding the pitfalls of short-lived solutions.

Every year, roughly 45 million Americans go on a diet and spend about $33 billion on weight loss products. Today’s diets often drive people to limit the amount of calories they consume or eliminate entire food groups. There’s the Atkins diet and the keto diet, along with intermittent fasting, the paleo diet, and Whole30. On TikTok, people promote all kinds of eating plans, including calorie counting, intuitive eating, and vegan, gluten-free, and dairy-free diets.[]

While these diets may help people lose weight in the short term, the results gained through fad dieting tend to be short-lived and cause considerable physical and emotional harm, according to a study recently published in Sage Journals.[] 

Dieting can snowball into weight cycling, or yo-yo dieting, in which people regularly alter their eating habits and dangerously cycle between losing and regaining weight. As the researchers put it, “Weight loss was often achieved at considerable cost, and typically fleeting, as the cycle continued.”[] 

Dana Ellis Hunnes, Ph.D., MPH, RD, a senior clinical dietitian at UCLA Medical Center, assistant professor at UCLA’s Fielding School of Public Health, and author of “Recipe For Survival,” says that diets may seem like an effective way to lose weight fast with little effort. “But the reality is that they're frequently not good for your health and do not have lasting results, which is really what people want but don't get with trendy diets,” says Hunnes. 

Why fad diets aren’t effective—or healthy 

These new findings suggest that unless someone needs to medically lose weight due to a health condition, it’s not recommended they go on a diet. “We found that dieting for aesthetic reasons, as most people do, results in so many harmful behaviors, ranging from disordered eating and exercise, [to] all-consuming thoughts about calories and the scale, to low self-esteem and confidence, missed out social opportunities and friendships, and, in general, not being very happy as weight yo-yos up and down,” the study’s co-author, Lynsey Romo, PhD, an associate professor in the Department of Communication at North Carolina State University, tells MDLinx.

In the short term, fad dieting may cause people to become irritable and moody, says Zachary Appenzeller, PsyD, a psychologist and Director of UTHealth Houston’s Center for Eating Disorders. In an effort to control what they eat, people may end up thinking excessively about food, he adds, which can lead to disordered eating and binge eating.[][]

Certain diets may cause people to become malnourished or lack crucial nutrients that make their bodies strong and healthy. People following the keto diet, for example, tend to restrict calories in a way that slows down their metabolism, explains Hunnes. When they revert to eating the way they did before the diet, their bodies store more fat, especially around the midsection, in an effort to preserve calories.[]

Weight cycling can have a disastrous impact on mental health: evidence has linked it to higher rates of depression, suicidal ideation, and poor body image. In addition, post-diet weight regain can increase risks of developing cardiovascular diseases, diabetes, and hormone-mediated cancers, such as breast cancer, Hunnes adds. In addition, eating excess amounts of meat, as is encouraged with the keto diet, can trigger inflammation and increase the risk of developing various cancers, including colorectal cancer. As a result, many diets shorten people’s lives and make them look and feel worse, Hunnes adds.[][][][][][]

“It is very hard for people to diet without regaining the weight, and then some, and for [the diet not] to take such a negative toll on people,” Romo says.

Why so many people fall for trendy diets 

According to the new study, while many people start dieting to get healthy and lose weight, people also do so to get thinner and to sculpt their bodies to cultural beauty standards. Past research has shown that people associate weight loss with a better life.[][]

“We live in a society that largely overvalues the importance of physical appearance, and currently, the trend is to idealize unrealistically thin, lean, and/or muscular bodies,” says Dr. Appenzeller. In addition, social media apps allow people to alter their body shape and appearance in photos. Other people may compare themselves to what they see in the images circulating on social media and experience dissatisfaction with their own bodies, evidence suggests.[] 

This, in turn, can lead to low self-esteem and disordered eating habits, including fad dieting. “When we ‘look good’ in the short term, it makes us feel better about ourselves, and people are constantly chasing that good feeling,” says Hunnes. This approach isn’t sustainable. Many people burn out and end up reverting to their old eating habits, causing them to quickly regain the weight they lost—and, in some cases, more. “We have yet to find a ‘magic bullet’ diet that helps people long-term to suppress their weight. [Fad diets] almost always come along with an array of negative psychological consequences that can range from mildly uncomfortable to severely impairing,” says Dr. Appenzeller.[] 

How to lose weight—and keep it off

The most effective way to maintain a healthy weight is by adhering to long-term healthy lifestyle behaviors, says Hunnes. “Quick fixes are rarely the answer,” she adds. She recommends eating a high-fiber, whole-food, plant-based diet. For those wanting to work with a nutritionist, she recommends looking for someone who promotes real, whole foods over supplements or prepackaged meal plans. Listen to your body: “Eat only as much as your body needs and wants. Don't overstuff yourself,” Hunnes says. 

Dr. Appenzeller believes that fad diets are one of the biggest scams out there: “Diet companies make billions of dollars a year off of this lie that we can somehow, [in the] long term, have the ability to suppress our weight below where our body would naturally like to be. [These companies] disregard the scientific literature that speaks to the contrary.”. Diets operate on the misguided premise that you can change your body if you try harder, eat less, and work out more. They ignore the fact that there is a general weight and size that our bodies are largely biologically predetermined to be, Dr. Appenzeller says.

His advice: Live your life by attending to the things you can change, like relationships, connections with others, and hobbies that bring you joy. “There is so much that life has to offer us, and people’s worth comes from so much more than their ability to control the size and shape of their organs,” Dr. Appenzeller says.

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