JAMA Netw Open

Weight loss in middle age: Do the benefits last a lifetime?

May 28, 2025

Losing weight in midlife—and keeping it off—was linked with decreased risks for chronic diseases (even beyond T2DM) as well as reduced all-cause mortality, according to this cohort study of data collected during an era before weight-loss drugs and surgical interventions were commonplace.

• Study data included 3 cohorts (N=23,149): Whitehall II (1985-1988), Helsinki Businessmen (1964-1973), and Finnish Public Sector (2000), which included height and weight data. Midlife was defined as age 40-50. Participants were sorted into groups based on baseline and follow-up BMI, with 25 as the key threshold; morbidity and mortality were assessed.
• After adjusting for various risk factors (smoking, systolic BP, cholesterol), the incidence of chronic diseases (T2DM, MI, stroke, cancer, asthma, COPD) was reduced in those with sustained midlife weight loss vs. those who were persistently overweight, according to data from two of the cohort studies. Even when T2DM was excluded from the analysis, results continued to be favorable for those with sustained weight loss.
• Mortality was decreased in those with sustained weight loss, according to data from one of the studies that included long-term follow-up.

Source:

Strandberg TE, et al. (2025, May 27). JAMA Netw Open. Weight Loss in Midlife, Chronic Disease Incidence, and All-Cause Mortality During Extended Follow-Up. https://pubmed.ncbi.nlm.nih.gov/40423973/