The Low-Fat Myth

Low-fat diets may be no more successful than higher-fat diets for lasting weight loss

/ Author:  / Reviewed by: Jennifer Gershman, PharmD, CPh

(RxWiki News) Cutting back on the butter, cream and fatty meats is probably a healthy choice. But it may not help you keep the pounds off in the long term.

A new study from Brigham and Women's Hospital and Harvard T. H. Chan School of Public Health found that low-fat diets may be no more successful than higher-fat diets in achieving and maintaining weight loss for longer than one year.

"Despite the pervasive dogma that one needs to cut fat from their diet in order to lose weight, the existing scientific evidence does not support low-fat diets over other dietary interventions for long-term weight loss," said lead study author Deirdre Tobias, ScD, a researcher in preventive medicine at Brigham and Women's, in a press release.

For this study, Dr. Tobias and team used data from 53 studies with a total of 68,128 patients to look at the difference in weight change between low-fat and other diets. Studies that included dietary supplements or meal replacement drinks were excluded from this analysis.

On average, these patients only managed to lose and keep off 6 pounds after one year or longer.

Compared to the patients on low-fat diets, those on low-carb diets were about 2.5 pounds lighter after one year or longer. Similarly, studies that included both higher-fat and low-carb diets yielded significantly greater weight loss than low-fat diets after one year.

Low-fat diets led to greater weight loss, however, when compared to "usual" diets, in which patients made no changes to their eating habits.

So what diets are the best for lasting weight loss?

According to Dr. Tobias and team, patients should look beyond the number of calories from fat, carbs, and protein in their diets and focus on healthy eating patterns, whole foods and portion size.

"The key is to improve long-term compliance and cardiometabolic health," said senior study author Frank Hu, MD, PhD, a professor of nutrition and epidemiology at Harvard, in a press release. "Therefore, weight loss diets should be tailored to cultural and food preferences and health conditions of the individual and should also consider long-term health consequences of the diets."

This study was published online Oct. 30 in the journal The Lancet Diabetes & Endocrinology.

The National Institutes of Health and the American Diabetes Association funded this research.

Dr. Ludwig disclosed royalties for books on nutrition and obesity. Dr. Hu disclosed support from California Walnut Commission and Metagenics.

Review Date: 
October 29, 2015
Last Updated:
November 9, 2015