A common diet mistake is limiting weight loss

Lots of people go on lots of diets. Many try to ease the transition by incorporating some of their favourite foods. Not only is that a bad idea, it may be sabotaging the diet before it even starts.

A new study in the Annals of Internal Medicine suggests dieters actually do a little better when they are not allowed to choose the foods they eat.

“A lot of investigators had concluded [previously] that we should give people a choice among diets, because that might optimize their weight loss,” the study’s lead author, Dr. William Yancy of the V.A. Medical Center in Durham, North Carolina, told Yahoo Canada.

“There were reasons to think they would do better. But they didn’t.”       

Over 200 subjects were tested in the study. Half were given the choice of whether to go on a low-fat or low-carb diet. The other half were assigned one randomly.

After a study period lasting almost a year, the dieters who chose their own plan had lost an average of 12.6 pounds. And the ones who didn’t? They dropped 14.7.

That may not seem a big difference in weight loss. But the difference from what was expected is worth examining.

“Yeah, it was surprising,” Yancy said.

“It just makes sense that you’d think if people choose their diet based on their preferences, presumably they would be able to stick to the diet better.”

A deeper look at the study’s procedures highlights the differing approaches the two groups of dieters agreed to follow.

“In both options studied, patients were taught how to diet, what kinds of foods to eat and avoid in both diets,” Yancy said.

“They were allowed to choose the foods within those directions. And they could prepare the foods at home, and they could go to a restaurant and choose the foods, but they were counselled how to choose the right foods to fit with the diet. That was the same for both arms of the study.”

“The difference is, the group that did not get to choose the diet had to stick with whatever diet counselling they received. They had to follow those general instructions.”

Yes, it’s just one study. Yes, it’s a relatively small number of subjects. But Yancy feels there are clues here that can help doctors and dieticians better guide their patients to better levels of weight loss.

“I think we need to figure out other ways to match people to the diet. We’re starting to see some research that people with certain metabolic test results might do better with one diet approach than another. It might be that there are other factors that can predict how people will do. It could be as simple as their personality or it could be other traits – but it doesn’t seem to be their food preferences.”