Low carb vs. low fat: what the DIETFITS trial found

The DIETFITS trial, published in JAMA in 2018 by Gardner and colleagues, randomly assigned 609 adults without diabetes to a healthy low-fat or a healthy low-carbohydrate diet for 12 months.

Both groups lost weight, and the difference between them was not statistically significant. Genetic patterns and insulin levels the researchers tested did not predict who would do better on either diet.

Both diets emphasized whole foods, vegetables and cutting added sugar and refined grains. That shared focus may matter more than the label on the diet.

What it means on the road: low carb is one solid option, not the only one. If skipping the bun and the fries is easier for you than counting fat, that is a good reason to choose it.