A University of Helsinki study tracked 23,000 individuals from Finland and the UK, aged 30 to 50 at the outset, over a period of 12 to 35 years. Health benefits were found in overweight men and women who lost an average of 6.5% of their body weight in early middle age and maintained it throughout the 12–35-year follow-up period. Weight maintenance is crucial.
“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,” notes Professor Timo Strandberg .
The study he led is now filling this gap.
“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 also supports the view that, for optimal health, a lifelong body mass index (BMI) under 25 is ideal.
The study was published in JAMA Network Open, the open-access journal of the American Medical Association.
JAMA Network Open
10.1001/jamanetworkopen.2025.11825
Observational study
People
Weight Loss in Midlife, Chronic Disease Incidence, and All-Cause Mortality During Extended Follow-Up
27-May-2025