Study links adult weight gain to major chronic diseases
The weight that Americans typically gain between ages 20 and 50 may raise their risk of developing major illnesses, according to a new study.
Even those who only gained 4.6kg faced a higher risk of major chronic diseases and ageing poorly, the study authors report in JAMA.
“In the past, most focus has been put on people who are already obese and how they should lose weight. The problem is that people don’t become obese overnight,” said senior study author Dr Frank Hu of the Harvard TH Chan School of Public Health in Boston.
“Americans start to gain weight in early adulthood and put on a small amount each year, such as a half-pound or pound, which adds up in the long-term,” Hu told Reuters Health in a phone interview. “Then it’s difficult to lose weight and maintain that lost weight. That’s why prevention is extremely important.”
The researchers analysed data from two large studies that followed nearly 93,000 US women and more than 25,000 US men over decades. Participants reported what their weights had been in young adulthood - at age 18 for women and age 21 for men - and again at age 55.
The study team then tracked health changes after age 55, including the development of various diseases, cognitive decline and physical limitations associated with ageing.
Women gained an average of 12.7kg over 37 years, and men put on an average 9.5kg over 34 years. Consistently across both genders, those who gained more weight were more likely to be physically inactive, non-smokers, have unhealthy diets and have more chronic diseases by the time they were in their 50s.
About one in five women and one in three men were considered to be ageing healthily in their 70s.
Compared to people who stayed close to their youthful weight, those who gained just 2.5kg to 10kg had nearly double the risk of type 2 diabetes, as well as 38% higher risk of gallstones and 9% to 25% increased the risk for hypertension, heart disease and cancer.
People who gained 10kg to 20kg had a quadrupled risk of developing type 2 diabetes, doubled risk of developing gallstones and 30% to 60% increased the risk of hypertension, heart disease and obesity-related cancer.
Gaining more than 20kg was tied to 10 times the odds of hypertension, three times the odds of gallstones and twice the heart disease risk of people who had stayed at the same weight.
“The overall results were not surprising because we know that excess weight gain is associated with many consequences, but the moderate weight gain statistics were sobering,” Hu said. “Most people gain more than 20 pounds, so this is a wake-up call for people.”
Each 10-pound increase in weight gain was associated with 17% reduction in the odds of ageing healthily.
“The good news about the obesity battle is that we’re seeing plateaus and decreases in children, but the bad news is we’re still seeing increases in adulthood,” said Dr William Dietz of George Washington University in Washington, DC, who wrote a commentary accompanying the study.
Dietz suggested turning toward workplaces to implement healthy living strategies and cut down on daytime snacking. Since most Americans spend their daytime hours at a workplace and since many workplaces bear the healthcare costs associated with absenteeism and lost productivity, corporations could make a big impact, he said. Targeting families could be another effective avenue, too, he added.
“The bottom line is that weight gain during adulthood is not benign,” Dietz said.
“With all of these adverse health consequences, we need to find ways to help adults prevent weight gain.”