For many adults, weight gain is slow and steady, but new research suggests that even a few extra pounds can boost your risk of chronic diseases such as type 2 diabetes and high blood pressure.
“People don’t become obese overnight,” said study lead author Dr. Frank Hu. He’s a professor in the departments of nutrition and epidemiology at Harvard T.H. Chan School of Public Health in Boston.
“On average, people gain about a half a pound to a pound per year. Most people gain weight all the way to 55 and up,” Hu said. “But once you cross the obesity threshold, it’s difficult to go back. This study provides very strong evidence that prevention of weight gain is very important.”
The researchers found that for every 11 pounds gained, the risk of diabetes went up 30 percent. The same weight gain was linked to a 14 percent increased risk of high blood pressure and an 8 percent higher risk of heart disease or stroke.
Each extra 11 pounds was also associated with a 6 percent increased risk of an obesity-related cancer, a 5 percent higher risk of dying prematurely, and a 17 percent decrease in the odds of healthy aging.
For those who gained significantly more weight, the researchers found dramatic rises in the risk of chronic illness. For example, for people who gained 44 pounds or more, the odds of type 2 diabetes spiked by 10-fold compared to those who kept their weight relatively stable over the years.
The risk of high blood pressure more than doubled, and the risk of developing heart disease or stroke was almost twice as high, according to the study. However, the research did not prove that weight gain caused these conditions.
The information came from two large-scale studies of health professionals in the United States. They included almost 93,000 women whose health was followed for 18 years, and more than 25,000 men whose health was followed for 15 years.
The women were asked to recall their weight at age 18. The men recalled their weight at age 21.
At age 55, the average weight gain for women was 28 pounds and for men it was 21 pounds.
The findings were published online July 18 in the Journal of the American Medical Association.
Dr. William Dietz is chair of the Global Center for Prevention and Wellness at George Washington University in Washington, D.C. He wrote an editorial accompanying the study.
“Virtually nothing is known about the factors that promote excess weight gain in adults,” Dietz said.
“I think one of the key periods for weight gain and weight retention is during pregnancy and the postpartum periods. There’s a significant disparity in the difference in excessive weight gain in women than men, and whether this explains that difference isn’t clear,” he said.
Dietz said it’s also unknown if changes in physical activity or nutrition from young adulthood to middle age are what’s behind the weight gain. But, more importantly, he said is that this time period represents a potential opportunity to intervene and prevent later obesity and the chronic illness that comes with it.
For example, if pregnancy is a time of significant weight gain, then obstetricians-gynecologists could play a role in obesity prevention.
“During pregnancy, gynecologists may provide weight counseling, but once a mother has delivered, she may not see the gynecologist for a while, and care shifts back to her primary care doctor, who may be uncomfortable raising the idea of obesity,” Dietz explained.
“But adult weight gain is not a benign condition. We need to help health care providers learn how to treat people with obesity,” he said.
On an individual level, both Hu and Dietz recommended monitoring your weight on a regular basis, especially during life transitions, such as getting married or becoming a parent. Step on the scale to see what you weigh, measure your waist circumference or pay attention to how your clothes fit. If you notice a change, get your weight in check sooner rather than later.
Although it’s never too late to gain health benefits from losing weight, it becomes much harder to take weight off and keep it off the heavier you get.
“If the dam is already open, the flood has already happened and it’s extremely difficult to rebuild the whole damn instead of repairing it,” Hu said.
“Prevention is much more important and much more effective. Health professionals should pay attention to even modest weight gain,” he said.
Learn more about preventing weight gain from the U.S. Centers for Disease Control and Prevention.