Want to live longer? Gradual weight gain — but not too much — could help, study says
A new study suggests that people who start adulthood with a body mass index (BMI) in the normal range, but then add pounds later in life and enter the “overweight” but not “obese” category, tend to live the longest.
These individuals even lived longer than those who remained in the normal weight range their entire lives, based on BMI levels determined by health officials, according to the study published Jan. 22 in the journal Annals of Epidemiology.
The Ohio State University researchers studied more than 8,000 people across two generations over the course of 66 years. They speculate that moderate weight gain through the years “may confer some survival benefits” that could protect against medical issues brought on by old age.
Meanwhile, people who started adulthood as obese and continued to gain weight had the highest mortality rate.
The researchers say their study adds to what we know about weight trends earlier in life and how they relate to mortality, potentially informing medical professionals on best practices for obesity-related treatments and plans.
“The impact of weight gain on mortality is complex. It depends on both the timing and the magnitude of weight gain and where BMI started,” study lead author Dr. Hui Zheng, an associate professor of sociology at The Ohio State University, said in a news release. “The main message is that for those who start at a normal weight in early adulthood, gaining a modest amount of weight throughout life and entering the overweight category in later adulthood can actually increase the probability of survival.”
The team analyzed data on 4,576 adults and 3,753 of their children from the Framingham Heart Study conducted in one Massachusetts town beginning in 1948. In both generations, the researchers studied and measured the adults’ BMI, which is based on height and weight, as well as medical histories over time.
They then used a model to control for other factors that can affect mortality, such as smoking status, gender, education, marital status and disease, and calculated how BMI was related to death rates. All participants were studied between age 31 and 80.
Among the adults and their children, those who started off at a normal weight, but became overweight — never obese — later on were the most likely to live a longer life. Adults who stayed in the normal weight range were the second most likely to survive, according to the study.
Next, were people who remained in a stable overweight range, followed by adults who leaned toward the lower level of normal weight. Only in the parent generation did those who were overweight and then lost some pounds come next on the survivability list.
Younger generations are becoming obese earlier in life
Although both generations generally showed the same results, the researchers found that the younger cohort faced some worrying realities.
People are becoming obese earlier in life compared to their parents, partly because medical advances are allowing more people to survive with obesity now than in the past.
Yet, those who are obese have contributed more to population deaths across generations — 5.4% in the parent cohort and 6.4% in the child cohort. That’s because more people are considered obese now.
The researchers say extra body weight gain in lean tissue and fat mass into adulthood may protect against nutritional and energy deficiencies, metabolic stresses, and loss of muscle and bone density due to chronic diseases such as heart failure. However, they admit more research is needed to fully understand the reasons behind their finding that moderate weight gain increases survivability.
The team also says more study should be done on people of different racial and ethnic backgrounds, as well as on individuals living in separate regions of the country. Their research included mostly white people in one Massachusetts town.
This story was originally published February 3, 2021 at 2:14 PM with the headline "Want to live longer? Gradual weight gain — but not too much — could help, study says."
