Cumulative weight gain over the course of early and middle adulthood may increase health risks later in life, according to a new study led by researchers from Harvard T.H. Chan School of Public Health. They found that compared with people who kept their weight stable, people who gained a moderate amount of weight (5 to 22 pounds) before age 55 increased their risk of chronic diseases and premature death, and decreased the likelihood of achieving healthy aging. Higher amounts of weight gain were associated with greater risk of chronic diseases.

The study was published online July 18 in JAMA.

“Our study is the first of its kind to systematically examine the association of weight gain from early to middle adulthood with major health risks later in life,” said senior author Frank Hu, professor of nutrition and epidemiology and chair of the Department of Nutrition. “The findings indicate that even a modest amount of weight gain may have important health consequences.”

To age better, eat better

Most people gain weight cumulatively during young and middle adulthood. Because the amount of weight gain per year may be relatively small, it may go unnoticed by individuals and their doctors — but the cumulative weight gain during adulthood may be large.

The researchers analyzed health data from 118,140 study participants, including 92,837 women in the Nurses’ Health Study between 1976 and 2012, and 25,303 men in the Health Professionals Follow-Up Study between 1986 and 2012. Participants were asked to recall their weight from early adulthood (age 18 for women, 21 for men) and to report their weight at age 55. Women gained an average of 22 pounds over early to middle adulthood, and men about 19 pounds.

Compared to those who kept their weight stable (not gaining or losing more than five pounds), those who gained a moderate amount of weight had an increased risk of major chronic diseases and premature death, and were less likely to score well on a “healthy aging” assessment of physical and cognitive health. In a meta-analysis of study participants from the two cohorts, each 5-kilogram (11-pound) weight gain was associated with a 30 percent increased risk of Type 2 diabetes, 14 percent increased risk of hypertension, 8 percent increased risk of cardiovascular disease, 6 percent increased risk of obesity-related cancer, 5 percent increased risk of dying prematurely (among never-smokers), and 17 percent decreased odds of achieving healthy aging.

“These findings may help health professionals counsel patients about the health consequences of weight gain. Prevention of weight gain through healthy diets and lifestyle is of paramount importance,” said Yan Zheng, who worked on the study while a postdoctoral fellow at Harvard Chan School and is now professor of epidemiology at Fudan University, China.

Other Harvard Chan co-authors of the study included JoAnn Manson, Changzheng Yuan, Matthew Liang, Francine Grodstein, Meir Stampfer, and Walter Willett.

The study’s cohorts were supported by grants from the National Institutes of Health. The study was supported by grants from the National Heart, Lung, and Blood Institute and the National Institute of Diabetes and Digestive and Kidney Diseases. Zheng was supported by a fellowship from the American Diabetes Association.