A study conducted at Boston University Clinic examined data for over 6,000 people enrolled in the Framingham Heart Study and as summarized on the Medscape portal concludes that “a maximum body mass index (BMI) over a 24-year period in adulthood that falls into obesity categories I [30-35 kg/m2] or II [35-40 kg/m2] is associated with an increased risk of premature death compared with those whose maximum BMI remains in the normal or overweight ranges, according to new research…. A significant association between maximum weight and mortality was not observed for the overweight category (BMI 25-30 kg/m2.).”
As further noted on Medscape, “Even after achieving normal weight, mortality rates were higher among individuals who were previously overweight (47.5 per 1000 person-years) and obese (66.7 per 1000 person-years) compared with those who never exceeded normal weight (27.9 per 1000 person-years).”
The study findings “indicate that yo-yoing weight is not beneficial when it comes to avoiding an early death, and they seem to also suggest that losing weight slowly is preferable to dropping the pounds rapidly.”
In a press release, the study’s authors caution physicians and researchers, “Prior studies of mortality risks of obesity have typically used a single point in time to measure adiposity status. Our study findings indicate that failure to incorporate weight history may introduce substantial bias into assessment of risk…. Regardless of the underlying mechanisms of weight loss in the present study, the fact that those who lost weight exhibited higher mortality risks in the present study reinforces the need to treat them separately from those who maintained normal weight across time, accomplished only by incorporating weight history.”
The study was recently published online at JAMA Network Open.