Why Some People Lose Weight Easily – and Others Don’t

Sharing the science, and what you can do about it

Sticking to a diet plan isn’t always as easy as it sounds—especially when it feels like results can be slow or unpredictable. A recent study sheds light on why some people succeed in weight-loss programs, while others struggle.

This study looked at a new weight-loss program designed to help people make lasting changes to their diets by teaching them how to choose healthier foods. Over the course of a year, participants attended 19 educational sessions and did homework to help them build better eating habits.

On average, participants lost about 6.5% of their body weight over the 12 months, which is a healthy and sustainable amount. For a 170-pound woman that is a loss of 11 pounds. About 40% of the participants had great success, losing more than 5% of their body weight. Some even reached a normal weight (BMI under 25).

So, what made the difference? It turned out that eating more protein and fiber helped people lose more weight. If participants started losing weight early on—within the first 3 months—they were more likely to keep losing and see long-term success. On the other hand, people who reported feeling depressed tended to lose less weight, which shows how important mental health can be in your weight-loss journey.

The big takeaway here is that the people who did the best in the program were the ones who stuck with it and made those dietary changes early on. So, if you’re looking to lose weight, getting started on the right track with healthy eating habits, focusing on protein and fiber can really set you up for success over time. And if you're struggling with depression or stress, it’s also important to address those factors because they can make it harder to lose weight.

Published January 1, 2025