When it comes to losing weight, it doesn’t matter which type of diet you choose as long as you stick to it, based on a one-year comparison of low-fat versus low-carb diets.
Published in the Journal of the American Medical Association, this study compared weight loss with low-fat versus low-carb diets. It also looked at the impact of genetics on success with one diet over another.
The results, however, suggest that both diets work equally as well—regardless of our DNA.
Conducted by researchers at Stanford University, this study included 609 overweight or obese adults from the San Francisco Bay area. Through the study, participants were randomly assigned to either a low-carb or low-fat diet for one year. During this period, they attended regular classes where they received dietary instructions and support from certified dieticians.
For the first two months, participants limited their intake of fat or carbohydrates to 20 grams a day, depending on their assigned diet. They then slowly added fat or carbs back into their diet, while keeping fat or carb consumption as low as they could maintain.
All participants were also encouraged to stay active and maintain a healthy diet throughout the study.
After one year, researchers found no significant difference in weight loss between either groups. Average weight loss was 12 pounds in the low-fat group and 13 pounds in the low-carb group.
Researchers also found that genes had no impact on weight loss in either group. Studies have identified three genes—PPARG, ADRB2 and FABP2—that could make individuals more responsive to either low-fat or low-carb diets. However, these genetic patterns had no impact on weight loss with either diet in this study.
Researchers also found no association between participants’ insulin levels and weight loss with either diet, despite evidence linking the two.
What findings show, according to authors, is that there’s no clear winner between low-carb and low-fat diets. Both are just as effective and can help people lose weight, especially when coupled with a healthy lifestyle. Findings also suggest that DNA doesn’t explain why certain individuals do better on one type of diet compared to another. What’s more important, according to authors, is that people find a diet that works for them and can be maintained over time.