Can't lose weight? Blame unrealistic expectations - study

A new study entitled “A large-scale observational analysis of social media data reveals major public misperception of the attainability of drastic weight loss by dieting,” appeared in the Karger, the multidisciplinary online journal for obesity research and therapy.

Clinical dietitians say these regimens are usually not enough to change one’s eating habits and lose and keep off excess weight. “The expectation of weight loss from being overweight to a normal weight with the help of a diet is almost never realistic,” asserts Dr. Irit Hochberg, director of the endocrinology, diabetes and metabolism institute and director of the diabetes service at Haifa’s Rambam Healthcare Campus who led the new study. In the medical and scientific community, this is a known fact that has been backed up by research for decades, but among the general public, this misconception somehow still exists.”

How did the researchers come to this understanding?

Hochberg based her conclusion on data analysis of 56,000 subscribers to forums on diet topics on the Reddit platform. Most overweight people who are in the process of dieting define for themselves as a goal to reach a desirable weight according to the body-mass index (BMI) calculation. In practice, everyone loses much less weight than expected. “Most diets that last for a long time bring about a loss of just a few kilograms,” Hochberg said. “This is what was found in clinical studies that examined the effects of various diets. It is difficult to lose weight, and it is even more difficult to maintain the weight loss over time. It’s surprising that most obese people still believe it’s possible and start a diet with the aim of reaching this goal.”

In the study, Hochberg and her coauthor Dr. Elad Yom-Tov from the Faculty of Data and Decision Sciences at the Technion-Israel Institute of Technology in Haifa collected the data of 56,000 people who participated in six forums dealing with different diets on the Reddit platform between the years 2011 and 2020. The participants, who reported in the discussion group that was defined around a certain diet with various dietary restrictions, provided diverse information about themselves and allowed the researchers to get a glimpse of the processes they went through.

The study followed the data that the various participants entered and the scope of their activity and actually analyzed their perceptions and beliefs regarding the success of the process against what actually happened.According to the results of the study, the average number of kilograms shed by the members of the forums who continued to participate over time ranged from 12 to16 kilos, with over three-quarters of those who continued to report on the forum losing at least five percent of their body weight. In a follow-up of several months, those on the ketogenic diet managed to lose the most compared to the other diets tested.

“Clinical studies that examined in a controlled environment the consequences of different diets on body weight loss in general and over time showed that they lead to a loss of only four to seven kilos on average and then a certain increase, so that in the long run, on average the people who persevere with the diet will weigh only three kilos less than what they started with,” Hochberg declared. “The participants in the forums we tested as part of the study aimed for a much greater weight loss, with a statement of intentions of losing weights that range from 24 to 37 kilos less than the weight with which they started. There are huge gaps between what actually happens and what most people believe they can achieve, even if they think they are aiming for a normal weight for their body structure and not extreme thinness.”

Those who stated from the beginning that their weight-loss goals were many kilos managed to lose more, but not in the order of magnitude for which they aimed. “They have false beliefs about the ability to bring about a radical change in our weight in the process of dieting. The pursuit of a goal that’s on the verge of the impossible creates a problematic cycle that produces self-hatred, a sense of failure and disappointment, turning to more extreme methods to achieve the goal –sharp fluctuations in weight that are harmful to health and even eating disorders. The social pressure from the environment that sends constant messages to the fat person that he must invest efforts to solve the problem and become a thin person, is also very harmful,” she continued.

But even if it’s impossible to completely change your body and become thin and toned, there is a very significant benefit to health even in losing a few kilograms. “We are all different, and there is no formula that fits everyone comprehensively, but this principle is enough,” she concluded. “The numbers speak for themselves.”