Weight Loss in 40s or 50s? Slash Your Chronic Disease Risk

Medscape

17-06-2025

People who reduce excess weight in midlife can roughly halve their risk of developing chronic disease later in life. That's the conclusion of three long-term studies from the UK and Finland, analyzed by a team led by Timo E. Strandberg, MD, PhD, professor of geriatrics at the University of Helsinki, Helsinki, Finland, and chief physician at its university hospital.
The findings, based on more than 23,000 participants, were published in JAMA Network Open .
Although the negative effects of obesity on health are well known, 'Few studies have examined long-term health benefits among individuals with sustained weight loss beyond its association with decreased diabetes risk,' wrote Strandberg and colleagues. Their analysis also looked at heart attack, stroke, cancer, asthma, chronic obstructive pulmonary disease, and overall mortality.
No Weight-Loss Drugs or Surgery Needed
'This publication again powerfully demonstrates that people have a large degree of control over their own health and can protect themselves from many illnesses — including age-related diseases — by preventing or reducing excess weight,' said Stephan Martin, MD, chief physician for diabetology of the Catholic Hospital Group Düsseldorf and director of the West-German Centre of Diabetes and Health, Düsseldorf, Germany, in an interview with Medscape's German edition .
'Another encouraging takeaway is that these results were achieved without weight-loss injections or surgical interventions,' Martin added.
Commenting on the analysis, Ga Eun Nam, MD, PhD, of Korea University College of Medicine in Seoul, Republic of Korea, and Yong-Moon Park, MD, PhD, of the University of Arkansas for Medical Sciences in Little Rock, Arkansas, noted that individuals who reached a healthy weight in midlife had long-term health outcomes comparable with those who maintained a healthy weight throughout adulthood.
Martin put it more simply: 'It's always worth losing weight.' Even those who reach a normal weight at 50 — or later — can still see health benefits.
Follow-Up Spanning Several Decades
Strandberg and his team evaluated three longitudinal studies that included repeated measurements of height and weight:
The Whitehall II Study, launched in 1985 (4118 participants; 72.1% men)
The Helsinki Businessmen Study, launched in 1964 (2335 male participants)
The Finnish Public Sector Study, with data starting from 2000 (16,696 participants; 82.6% women)
The follow-up periods ranged from 12 to 35 years.
Participants, with an average starting age of about 40, were divided into four groups:
Those with consistently normal weight (BMI < 25)
Those who reduced from overweight to normal weight
Those who gained weight (normal to overweight)
Those who remained overweight (BMI ≥ 25)
Diabetes Risk Not the Only One Reduced
In the Whitehall II Study, with an average follow-up of 22.8 years, a BMI reduction from ≥ 25 to < 25 over approximately 6 years in midlife was associated with a lower risk of developing chronic diseases.
After adjusting for potential confounders such as smoking, blood pressure, and lipid levels, the researchers calculated a 48% lower risk for chronic illness compared to those who remained overweight. Remarkably, this association held even after excluding participants who developed diabetes during follow-up. In that case, the risk reduction was 42%.
The Finnish Public Sector Study, with a 12.2-year follow-up, confirmed the findings, showing a 57% reduced risk for chronic illness.
Effects Independent of Gender and Hormonal Status
The Helsinki Businessmen Study, which had the longest follow-up (up to 43 years; mean, 35 years), showed that weight loss in midlife was associated with a 19% reduction in overall mortality.
Separate analyses by sex revealed that the association held for both men and women. Even menopausal status did not significantly affect the outcomes: Similar protective effects were observed in women younger and older than 50 years.
Midlife as a Critical Window for Intervention
'As we continue facing the global obesity epidemic, this study provides valuable epidemiologic evidence on long-term associations between weight management and major health outcomes,' wrote Nam and Park. While further research is needed to refine intervention strategies, 'these results highlight midlife as a potentially critical window for weight management and reinforce the importance of sustained weight management in chronic disease prevention and longevity.'
The study was conducted in a time when neither surgical nor pharmacologic weight loss interventions were common. 'Sustained midlife weight loss compared with persistent overweight was associated with a decreased risk of chronic diseases beyond type 2 diabetes and decreased all-cause mortality,' Strandberg and colleagues concluded.
Diet as the Main Lever
Martin said the findings confirm the importance of lifestyle in achieving and maintaining a healthy weight.
'Most chronic diseases caused by obesity stem from lack of physical activity and poor diet,' he noted. Foods that spike blood glucose and insulin levels should be avoided. 'Insulin inhibits fat breakdown, so it contributes to weight gain,' he explained.
A long-term strategy for staying lean and healthy, Martin said, includes minimizing intake of white bread, fries, chips, chocolate, soda, and other highly processed foods.