Weight regain after dieting is often framed as failure. But new long-term research suggests the story may be more complex.
A study published in BMC Medicine followed participants from two randomized controlled Mediterranean diet–based trials for five and 10 years. Researchers analyzed nearly 500 adults who participated in two structured, 18-month lifestyle interventions known as DIRECT-PLUS and CENTRAL. About one-third of participants from the first trial later enrolled in the second. Both programs emphasized Mediterranean-style dietary patterns and physical activity and included detailed MRI scans to measure visceral fat.
At the start of the second intervention, many returning participants had regained the weight they had previously lost. On the scale, they appeared to be back at baseline.
However, MRI data told a different story.
Compared with their original baseline measurements, participants showed approximately 15-25% improvements in abdominal fat distribution and metabolic markers, including enhanced insulin sensitivity and a more favorable lipid profile. These improvements persisted despite weight regain.
“Persistent commitment to a healthy dietary change creates cardiometabolic memory in the body,” said Prof. Iris Shai, the study’s principal investigator. “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.”
Visceral fat, stored deep in the abdominal cavity, is considered more metabolically active and more strongly associated with cardiometabolic disease risk than subcutaneous fat. Because it cannot be seen directly on the scale, changes in visceral fat may not always track with changes in total body weight.
Even during the second intervention, when weight loss was smaller than during the first attempt, participants maintained improved long-term outcomes. Five years after completing the second program, they experienced less abdominal fat accumulation compared with participants who had only taken part once.
“Body weight alone does not capture changes in visceral fat or metabolic biomarkers,” said Hadar Klein, the study’s lead author. “Even when weight is regained, cardiometabolic health may remain improved, and success should not be defined solely by the number on the scale.”
Importantly, these findings reflect structured, evidence-based lifestyle programs that included Mediterranean dietary patterns and physical activity. The study does not suggest that repeated crash dieting or extreme restriction is beneficial. Instead, it indicates that prior periods of sustained healthy behavior may leave lasting metabolic effects, even if weight fluctuates over time.
The results add nuance to the conversation around weight cycling. While repeated weight regain has often been viewed as harmful, this long-term MRI-based analysis suggests that participating in structured lifestyle interventions more than once may confer cumulative metabolic benefits.
This study was supported by grants from the Deutsche Forschungsgemeinschaft, the German Research Foundation.