COLUMBUS, Ohio — A new study finds maybe having a “dad bod” isn’t such a bad thing after all. Researchers from The Ohio State University say people who enter adulthood at a normal weight and start to pack on the pounds later in life actually live the longest.
Associate professor of sociology Hui Zheng and his team looked at two generations of Americans, following the residents of one city in Massachusetts and their children for nearly 70 years. Their findings reveal young adults with a healthy body mass index (BMI) who gradually become overweight — but never obese — have the greatest lifespans. These adults even lived longer that those who kept a normal BMI throughout their whole life.
On the other hand, the dangers of obesity remained constant throughout the study. Children who start adulthood already obese and continue to gain weight have the highest mortality rates, researchers say.
“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,” Hui Zheng says in a university 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.”
Younger generations less healthy than their parents?
The study examined the health histories of 4,576 people in the Framingham Heart Study and 3,753 of their children. This review began in 1948, following the parents until 2010. For the children, researchers followed them from 1971 through 2014. The OSU team notes most of the participants in the report are white.
While the weight gain trends were fairly similar across both generations, researchers say the younger group actually shows more worrying trends when it comes to becoming obese at earlier ages. In fact, the children in the study were more likely to die due to increasing obesity than adults in their parent’s generation.
Zheng says nearly all the adults in the original Framingham Heart Study had died by the end of the review. This gave researchers the ability to see how BMI evolves over time and provided an accurate estimate of how obesity affects the human lifespan.
Study authors examined the group’s health records from age 31 to 80; focusing mainly on BMI. This measurement is based on a person’s height and weight, which helps health professionals categorize patients as either underweight, normal, overweight, or obese.
The right weight path can lead to a longer life
The results reveal the older generation fell into seven distinct BMI trajectories (or paths) throughout their lives. The younger generation only followed six unique weight paths. Unlike their parents, the younger generation did not have a group with a downward weight trajectory — who lost weight throughout their lives.
After factoring out differences caused by smoking habits, gender, disease, marital status, and education, the team finds these BMI paths have unique connections to mortality risk.
For both generations of Americans, people starting adulthood at a normal BMI before moving into the overweight range later on had the best odds of living a long life. Those who kept a normal weight throughout their lives had the second-best odds of surviving the longest.
After those weight groups, overweight people who maintain their BMI come in next, followed by people with a lower (but still normal) level of BMI. For the older generation, people who were overweight at lost weight later on finished behind these groups.
Obesity and its link to an early death
Researchers say the worst groups to be in are two trajectories which see people start as obese and keep adding on weight. This trend, unfortunately, is more prevalent in younger generations.
“The higher BMI trajectories in the younger generation tend to shift upward at earlier ages relative to their parents,” Zheng reports.
The study finds the amount of participants with higher BMI paths increased among the younger group. Although people are more likely to survive the health complications obesity can cause today, study authors warn it’s still a problem when it comes to living a full and long life.
“Even though the mortality risks associated with obesity trajectories have decreased across the generations, their contributions to population deaths increased from 5.4% in the original cohort to 6.4% in the offspring cohort,” the OSU researcher adds. “That’s because more people are in the obesity trajectories in the offspring cohort.”
“Now, with this study, we know more about weight trends earlier in life and how they are related to mortality,” Zheng concludes.
The study appears in the journal Annals of Epidemiology.