People can improve their health through dietary and lifestyle changes even if they do not lose weight, according to a new international study.
The research, conducted by Israel’s Ben Gurion University, Harvard University, and Leipzig University, focused on people described as “weight loss resistant” — those who adopt healthy habits but struggle to shed pounds.
Published in the European Journal of Preventive Cardiology, the study challenges the long-standing belief that weight loss is the primary sign of a successful diet. Researchers found that even participants who did not lose weight showed measurable improvements in key health indicators.
The study tracked 761 adults between 18 to 24 months. All participants followed lifestyle changes without taking supplements or medications and were assigned to healthy diets. Participants also received free gym access and exercise guidance.
By the end of the trial, about one-third of the participants had not lost weight, despite following the program closely. However, they showed improvements in metabolic health, including higher levels of “good” HDL cholesterol, lower levels of leptin (a hormone primarily produced by fat cells), and reductions in abdominal fat, confirmed through MRI scans.
Researchers also identified 12 genetic markers that may influence whether a person is likely to lose weight through lifestyle changes, an insight that could help personalize future diet plans.
The findings suggest that healthy eating and exercise can provide significant health benefits even without weight loss, including reduced risk of heart disease and diabetes, the researchers said.