Weight Loss in Midlife Linked to Long-Term Health Benefits: Study Finds

A study published in JAMA Network Open reveals that sustained weight loss in early middle age can lead to major health improvements and a longer life. Conducted by researchers at the University of Helsinki, the study tracked over 23,000 individuals from Finland and the United Kingdom over a period ranging from 12 to 35 years, offering one of the most comprehensive long-term looks at the effects of lifestyle-based weight management.

As global obesity rates continue to rise, researchers have long debated the true long-term benefits of weight loss outside of diabetes prevention. This new study, led by Professor Timo Strandberg, provides strong evidence that maintaining a healthier weight starting in midlife can significantly improve overall health outcomes. The participants, aged 30 to 50 at the beginning of the study, were followed for decades to assess how their weight changes impacted their long-term health.

Those who were overweight at the start and successfully lost an average of 6.5% of their body weight—then maintained that loss throughout the follow-up period—were found to have clear health advantages compared to those who did not. The researchers emphasize that it wasn't just the weight loss itself that mattered, but the ability to keep the weight off long-term. “Weight maintenance is crucial,” the study notes.

Professor Strandberg highlighted the significance of these findings in the context of today’s growing obesity crisis. “The benefits of lifestyle-based weight management are widely discussed even though studies have found it surprisingly difficult to demonstrate health benefits beyond the prevention of diabetes,” he said. “I hope the findings will inspire people to see that lifestyle changes can lead to major health improvements and a longer life. This is particularly important today as more people are overweight than when the collection of our research data began 35 years ago.""

The study further reinforces the health guideline that maintaining a lifelong body mass index (BMI) under 25 is ideal. As more people face weight-related health challenges than ever before, this research offers compelling motivation to adopt and sustain healthy lifestyle habits.

Reference: Timo E. Strandberg, Arto Y. Strandberg, Satu Jyväkorpi, Annele Urtamo, Solja T. Nyberg, Philipp Frank, Jaana Pentti, Kaisu H. Pitkälä, Mika Kivimäki. Weight Loss in Midlife, Chronic Disease Incidence, and All-Cause Mortality During Extended Follow-Up. JAMA Network Open, 2025; 8 (5): e2511825 DOI: 10.1001/jamanetworkopen.2025.11825