Why Should You Stop Dieting? Because Diets Don't Work — Experts Explain 7 Reasons Why

In 2007, Traci Mann, who has a PhD in psychology, conducted a review of every randomized controlled trial of diets and included a follow-up of at least two years. She and her team discovered that one-third to two-thirds of dieters regained more weight than they lost on their diets — more weight! Lauren Cadillac, RD, CPT, a certified intuitive eating counselor, explained that this proves that dieting is a predictor of weight gain, which means if you diet, you could end up weighing more than you did before you started.

In 2013, Mann updated her review with studies she missed as well as newer studies and the results were the same. While dieters in the studies had lost weight in the first nine to 12 months, and over the next two to five years, they had gained back all but an average of 2.1 of those pounds. Participants in the control groups who did not diet also gained weight during those same years, but an average of just 1.2 pounds.

One study showed that half the dieters weighed over 11 pounds more than their starting weight five years after starting the diet. The dieters made little progress in terms of their weight, and the non-dieters weights weren't greatly affected by their lack of dieting. Mann said in the study, "In sum, it appears that weight regain is the typical long-term response to dieting, rather than the exception."

From the 2013 Australian Research Council's clinical guidelines for the management of obesity, they discovered that after ending dieting, people end up gaining back most of the weight lost within two years. Within five years, most people gained back all the weight. O'Malley explained that this research proves that regardless of participants being able to lose weight initially, it wasn't in a way that the participants could maintain.

O'Malley shared a great quote from Evelyn Tribole, registered dietitian and co-author of Intuitive Eating, "The weight loss industry is the only industry where a customer buys a product that doesn't work and the manufacturer blames the customer."

If a person isn't consuming adequate calories or they're cutting out certain food groups, they may be missing out on essential vitamins, minerals, and nutrients their body needs to function normally. Cadillac said this can cause a weakened immune system, loss of muscle, cardiovascular issues such as high blood pressure, cardiovascular disease or stroke, metabolic syndrome, and increased mortality risk. Yo-yo dieting in women, where you cycle between losing and gaining weight, can also increase heart disease risk.

Some will argue that being at a higher weight is unhealthy, but O'Malley said that research shows those at higher weights can have similar or better health markers than those at lower weights. This type of research is what helps us untangle the assumption that our weight equals our health, which is often the basis for the push to lose weight. O'Malley said, "Recognising this research and having more of us know this helps us to be more critical of diet culture messages around the need to lose weight to be healthy, because we know that's not always the case. And combined with weight cycling research, we can see that even the pursuit of weight loss over time with different diets can actually result in worsened mental and physical health markers."

It was proven in The Biggest Loser studies O'Malley brought up when we saw contestants having extreme changes in weight, and also saw significant changes to their metabolisms — they slowed, meaning their basal metabolic rate (BMR) was much lower than it had been before.

Extreme calorie restriction through diet and exercise slows down your metabolism, so not only will you eventually stop losing weight, but as soon as you eat a little more or exercise a little less, you'll gain weight.

Your body is smart. It's wants you to survive. It doesn't care that you want a six-pack. If you don't feed it adequate calories to sustain your body's essential functions, your metabolism will slow down so you won't lose weight.

Leptin is the hormone that sends the "I'm full" message to your body, so you stop eating. Researchers from The Biggest Loser study also found that dramatic weight loss caused a decrease in leptin levels, which lead to increased cravings and hunger. It's impossible to fight these strong physical urges, making it more difficult to continue with a low-calorie diet.

All the experts agreed that dieting can lead to obsessively counting calories and macros, constantly thinking about food, increased cravings and hunger, bingeing in response to restricting, as well as eating disorders like anorexia and bulimia. Having your brain consumed by your weight, what you eat, and what you look like will affect your relationships, your school or work, and could even be fatal.

One of the best examples of the effects of dieting is the Minnesota Starvation Experiment in 1944, O'Malley shared. Thirty six men were selected from a couple hundred volunteers. The goal was to help researchers and relief workers learn how to help people recover from starvation during WWII by studying the psychological and physiological effects of starvation.

The important takeaways to highlight from this study are that after the 'semi-starvation' period of six months where the men ate 1,570 calories per day (3,200 calories a day was normal), the participants reported experiencing depression, apathy, decreased sex drive, decreased strength and stamina, as well as reduced body temperature and heart rate.

They also displayed symptoms of obsession with food - dreaming and fantasizing about food, reading about food, reading cookbooks, talking about food, and savoring their meals with ritual-style eating that prolonged mealtime. Following the study, even after the men were allowed to resume "normal" eating, the participants would binge on large quantities of food, and for some men, this continued later than eight months after the study. "This demonstrates the long-term effects of restriction on the body," O'Malley said.

"This is very similar to what we see in behaviour of not only those who struggle with eating disorders but also very normalized behaviours from those who diet or restrict eating in some way," added O'Malley.

Cadillac added that dieting can also lead to social anxiety, social withdrawal, and feelings of failure. As if that wasn't bad enough, Previte said feeling bad about your weight and constantly dieting can also cause anxiety, poor self-esteem, as well as suicidal thoughts.

O'Malley noted that the men's calorie allowance was definitely low, but not as low as you might think for a "starvation study." She said that "many calorie-tracking apps and meal plans are giving similar numbers and that more often than not, those numbers are underestimating your needs." So while your calories may not be so low that you're starving, they may be so low that they're causing these emotional issues.

1. Ask Yourself, Has Dieting Worked For You in the Past?

   O'Malley suggested being honest with yourself and asking, what has dieting done for you in the past — mentally, physically, emotionally, socially? Has it lived up to your expectations? Were there any side effects?

   She said that it's OK if there are pieces of dieting that you really liked or miss. Some common examples of this are the community aspect that many diet programs offer and the structure or feeling of control. Finding a community around non-dieting can be so helpful, and social media is a great place to start. "Let's bust the myth that not dieting means chaos and eating whatever you want whenever you want! There can be and definitely is structure around intuitive eating and a non-diet approach," O'Malley said.

2. Reject Diet Mentality

   Previte said this is one of the 10 principles of intuitive eating. "This has to come first. You can not have one foot in diet culture and one foot in food freedom," she said.

   Unfollow social media accounts that are triggering, delete calorie-counting apps, throw away the fad-diet pills, and cancel your diet subscription. Seek out a support group, a non-diet dietitian, and a therapist to help you say no to diet culture. Find non-diet resources to educate yourself on intuitive eating and ditching diets. Previte also said to "Give yourself grace! This is hard if your whole life has been consumed by dieting for years on end. It takes time to break down these diet culture neural pathways in the brain and create new ones."

3. Make Peace With Food

   This is another of the 10 principles of intuitive eating. Previte said there should be no morality tied to your food choices — no food is good or bad. She added, "Once we truly believe this we can drop the guilt, self-judgement, and shame associated with our food choices and start becoming curious about why our behaviours are the way they are."

   Allowing all food to be available to you is part of this, said O'Malley. In the beginning, this might mean eating more of certain foods than usual, especially if they're foods you've restricted in the past. "This is normal! As you continue to allow yourself access to those foods, the more intense cravings will reduce and you'll be better able to make food choices without the guilt or 'bad' labels," she reassured.

4. Honour Your Hunger and Respect Your Fullness

   These are two more of the 10 principles of intuitive eating. Previte said, "Learn to shift your focus from external diet rules to focusing on how you feel related to your food choices."

5. Remember That It's a Process!

   Think about how long you've dieted or restricted certain foods or tried to lose weight, O'Malley said. "For many, it's years, so it makes sense and is completely normal for this process to not all come at once."

   She said that it's helpful to celebrate the small wins throughout your journey, like being able to go order something off a menu that you really want, saying "yes" to spontaneous plans with friends, keeping something like ice cream in your house, or buying a pair of jeans even if they're a different size than usual. "Those pieces add up to really big shifts and freedom in the short and long term," O'Malley said.

6. You Don't Have to Do It Alone

   This is a lot to navigate on your own, and you may be more successful with a little support. There are tons of intuitive eating and antidiet resources, like podcasts, books, and Instagram accounts.

   If you need more support, "Finding the non-diet movement and dietitians, therapists, and doctors who work from a non-diet approach can help you find a more sustainable, healthy relationship with food, exercise, and your body," O'Malley said. So reach out for help if you need it.