An extensive literature of epidemiology demonstrates that being overweight correlates with increased age-related disease, increased medical expenditure, and increased mortality. The greater the excess weight, the worse the outcome. While human studies can largely only uncover correlations between lifestyle choice and health, animals studies convincingly demonstrate that carrying too much visceral fat is disruptive to health and life span. Visceral fat tissue is metabolically active, promoting increased chronic inflammation via a range of mechanisms.
The human evidence leans in the direction of harms being proportional to both the amount of excess visceral fat and the length of time for which that fat is carried. For example, consider the studies in which the highest lifetime waist circumference measure produces better correlations with outcomes in aging than more recent measures of weight and visceral fat burden. In a similar vein, in today’s open access paper, researchers show that overweight individuals who achieved sustained weight loss starting in mid-life exhibit a much reduced risk of chronic disease in later life. The point to take away from all of this is that excess visceral fat tissue is very harmful.
Weight Loss in Midlife, Chronic Disease Incidence, and All-Cause Mortality During Extended Follow-Up
Few studies have examined long-term health benefits among individuals with sustained weight loss beyond its association with decreased diabetes risk. This cohort study analyzed data from 3 cohorts that included repeated height and weight measurements: the Whitehall II study (WHII; baseline, 1985-1988), Helsinki Businessmen Study (HBS; baseline, 1964-1973), and Finnish Public Sector study (FPS; baseline, 2000). Participants were categorized into 4 groups based on their first 2 weight assessments and followed up for morbidity and mortality outcomes. Data analyses were conducted between February 11, 2024, and February 20, 2025. Midlife BMI change was categorized as persistent BMI less than 25, BMI change from 25 or greater to less than 25, BMI change from less than 25 to 25 or greater, and persistent BMI of 25 or greater.
There were 23,149 participants, including 4,118 men and women (median age at first visit, 39 years) from WHII, 2,335 men (median age at first visit, 42 years) from HBS, and 16,696 men and women (median age at first visit, 39 years) from FPS. During a median follow-up of 22.8 years, after adjusting for smoking, systolic blood pressure, and serum cholesterol at the first evaluation, WHII participants with weight loss had a decreased risk of developing chronic disease (hazard ratio [HR], 0.52) compared with participants with persistent overweight. This finding was replicated after excluding diabetes from the outcome (HR, 0.58). The corresponding HR in FPS was 0.43 over a median follow-up of 12.2 years. In HBS, weight loss was associated with decreased mortality (HR, 0.81) during an extended follow-up (median 35 years).
