Diets work, but which one doesn’t matter

September 2, 2014 in Nutrition Topics in the News, Weight Management

Diets work, but which one doesn’t matter

When it comes to popular weight loss diets, which one you follow doesn’t make much difference as to amount of weight lost, according to a new review.

Low-carb (defined as 40% or fewer calories from carbohydrate) or low-fat  (defined as less than 20% calories from fat) diets resulted in the most weight loss, but despite a difference of a few pounds between groups, all the programs in the study were about equally effective.

The weight loss differences between different diet programs were small with likely little importance to those seeking to lose weight. Any diet program should include exercise and behavioral support.

The analysis included 49 randomized controlled trials that tested 11 popular diets for at least three months. All of the participants were overweight or obese, and they all had daily nutrient or calorie targets. Some had exercise goals as well.

The low-carb diets, like Atkins, South Beach and Zone, require that no more than 40 percent of daily calories come from carbohydrates and another 30 percent come from protein.

The low-fat diets, including the Ornish and Rosemary Conley diets, specify that less than 20 percent of calories come from fat, and 60 percent come from carbohydrates.

The analysis also included trials of moderate macronutrient diets like Biggest Loser, Jenny Craig, Volumetrics, Nutrisystem and Weight Watchers, which also require around 60 percent of calories from carbohydrates but allow more from fat and less from protein than the low-fat diets studied.

Compared to no diet at all, each of the diets produced more weight loss, but low-fat and low-carb were most successful.

At the six-month point, people on low-carb diets had lost an average of 19 pounds, which dropped to 16 pounds at one year. Low-fat dieters lost an average of more than 17 pounds by six months, which also dropped to 16 pounds by one year.

Moderate macronutrient dieters lost an average of 12.5 pounds after one year.

The different diets within each category didn’t make much difference, the study found.

Though the moderate macronutrient diets in the review resulted in slightly less weight loss than others, they may still be the best choice for some people, experts say. These diets provide the greatest variety so they are easier to follow for some people.

Dietitians can help assess which diet program a person is most likely to stick to and achieve lasting weight loss, as well as a diet’s potential impact on other health measures like cholesterol and blood pressure. A meal plan can then be customized to an individual's needs.

“We know that you can achieve weight loss with more than one type of diet,” Malone said. “The diet that really should be presented or offered to people is the one they’re going to stick to.”

As I tell my clients, everything you do to lose weight should be the same thing you do to keep the weight off.  There is no one-size-fits-all. A weight loss diet should be sustainable for the long term – and healthy, of course.

Source: JAMA, September 2, 2014.

All research on this web site is the property of Leslie Beck Nutrition Consulting Inc. and is protected by copyright. Keep in mind that research on these matters continues daily and is subject to change. The information presented is not intended as a substitute for medical treatment. It is intended to provide ongoing support of your healthy lifestyle practices.