Repeated cycles of weight loss and regain may leave behind lasting metabolic benefits.
A new study from researchers at Ben-Gurion University of the Negev suggests that the much-criticized cycle of “yo-yo dieting” may not be as harmful as once thought. In fact, repeated attempts at weight loss could leave behind lasting improvements in metabolic health, even when the weight eventually returns.
“Yo-yo dieting” describes a cycle in which people lose weight through lifestyle changes and then gradually regain it, often repeating the process multiple times.
These fluctuations affect more than body weight. They also influence body composition, especially visceral (intra-abdominal) fat, which is closely linked to cardiometabolic disease. As a result, an important question is not just whether weight loss works once, but whether repeated efforts help or harm long-term health.
Rethinking Weight Loss and “Cardiometabolic Memory”
Prof. Iris Shai, the study’s principal investigator from Ben-Gurion University of the Negev, dean of the School of Sustainability at Reichman University, an adjunct professor at Harvard T.H. Chan School of Public Health, and an honorary professor at Leipzig University, Germany, said the findings challenge the idea that weight loss success should be judged only by the scale:
“Persistent commitment to a healthy dietary change creates cardiometabolic memory in the body. Repeated participation in a lifestyle program aimed at weight loss, even after an apparent “failure,” in which an individual regains all the weight lost in a previous diet- may lead to significant and sustainable health benefits over the years, particularly through the reduction of harmful visceral (abdominal) fat.”
Lead author Hadar Klein, RD MSc, a doctoral student, emphasized that body weight alone does not tell the full story:
“Body weight alone does not capture changes in visceral fat or metabolic biomarkers. Even when weight is regained, cardiometabolic health may remain improved, and success should not be defined solely by the number on the scale. Importantly, even when weight loss is attenuated during a second attempt, the cumulative benefits for abdominal fat and metabolic health are substantial.”
Study Design and Long-Term Follow-Up
The study, published in BMC Medicine, tracked participants over both 5- and 10-year periods using data from two consecutive randomized controlled dietary trials (DIRECT-PLUS and CENTRAL), which together included about 500 participants.
Each trial lasted 18 months and involved roughly 300 participants. About one-third of those in the first trial went on to join the second. The researchers compared Mediterranean diet–based interventions and physical activity with control diets. MRI scans were conducted before and after each intervention to closely measure changes in body composition.
Despite returning to nearly the same body weight at the start of the second intervention, participants showed clear metabolic improvements. Their abdominal fat distribution and metabolic markers were more favorable than at the original baseline, with gains of about 15–25%, including better insulin sensitivity and improved lipid profiles. These results point to a lasting “cardiometabolic memory” from earlier weight loss efforts.
Long-Term Benefits of Repeated Interventions
Participants who joined the program a second time tended to lose less weight during that round. Even so, their long-term outcomes were better.
Five years after completing the second intervention, they had regained less weight and accumulated less abdominal fat than those who had participated in a weight loss program only once.
Reference: “How effective is rejoining a long-term weight loss program? The 5- and 10-year MRI-assessed Follow Interventions Trial (FIT) project” by Hadar Klein, Dafna Pachter, Dana Tamar Goldberg Toren, Omer Kamer, Liav Alufer, Noa Ebstein Karamani, Yoash Chassidim, Ilan Shelef, Assaf Rudich, Uri Yoel, Gal Ben-Arie, Hila Zelicha, Anat Yaskolka Meir, Gal Tsaban, Carmi Bartal, Matthias Blüher, Michael Stumvoll, Uta Ceglarek, Berend Isermann, Lu Qi, Meir J. Stampfer, Frank B. Hu and Iris Shai, 30 January 2026, BMC Medicine.
DOI: 10.1186/s12916-026-04663-9
The trials were conducted at Ben-Gurion University of the Negev, Israel, together with researchers from Harvard, Leipzig, and Tulane and in collaboration with the Dimona Nuclear Research Center, Briuta Medical Center, and Soroka University Medical Center.
This work was supported by grants from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation). Funding providers did not participate in any stage of the study’s design, conduct, or analysis, and they had no access to the study results before publication.
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