Want to live longer? Start at normal weight and gradually add on the pounds

People who enter adulthood with a body mass index (BMI) in the normal range and move later in life to being overweight, but never obese, tend to live the longest, says a new study.

By: Jahnavi Sarma | | Published: February 5, 2021 10:40 am

The least likely to survive were two trajectories involving those who started as obese and continued to gain weight.

Weight is always an issue with most people. Many with perfectly normal weight often fret about being on the heavier side. Even a kilo more on the weighing scale is enough to send them over the edge. Crash diets, excessive exercises follow, and you heave a sigh of relief only when you reach the weight you decided you should be at. But, if experts are to be believed, gradual weight gain may actually help you live longer. According to researchers from The Ohio State University, people who start adulthood with a body mass index (BMI) in the normal range and move later in life to being overweight – but never obese – tend to live the longest. The most surprising find of this study was that adults in this category lived longer than even those whose BMI stayed in the normal range throughout their life. Those who started adulthood as obese and continued to add weight had the highest mortality rate. The study was published recently online in the journal Annals of Epidemiology. Also Read - 5 exercises that curb your hunger and help you lose weight

Weight gain and mortality share a complex relationship

According to researchers, the impact of weight gain on mortality is very complex. It depends on the timing as well as the magnitude of weight gain and where BMI started. The main message that comes from this study is that people who start at a normal weight in early adulthood and gain a modest amount of weight throughout life and enter the overweight category in later adulthood can actually increase the probability of survival. Similar results were found in two generations of mostly white participants in the Framingham Heart Study, which followed the medical histories of residents of one city in Massachusetts and their children for decades. Also Read - Media multitasking can lead to obesity

But obesity can raise the risk of early death

But the scenario for the younger generation is worrying. This generation is becoming overweight and obese sooner in their lives as compared to their parents. They are also more likely to have obesity-related deaths. Also Read - Low body weight can increase the risk of developing anorexia nervosa in kids, reveals study

BMI trajectory reveals risk

The researchers used data on 4,576 people in the original cohort of the Framingham Heart Study, and 3,753 of their children. The heart study started in 1948 and followed participants through 2010. Their children were followed from 1971 to 2014. The members of the original cohort had almost all died by the end of the study, so the results can uncover how body mass index (BMI) evolves over all of adulthood and provide a more accurate estimate than previous studies of how obesity is linked to mortality. In both generations, the researchers looked at data from those aged 31 to 80. The main measure was BMI, which is based on a person’s height and weight and is used as a thumb rule to categorize a person as underweight, normal weight, overweight or obese.

After analyzing data on how the participants’ BMI change over the years, the researchers found that the older generation generally followed one of seven BMI trajectories throughout their lives whereas the younger generation had six trajectories. But there were not enough people in the younger generation who lost weight through their lives to have a downward weight trajectory as was present in their parents’ generation.

Being obese and still gaining weight is dangerous

After controlling for a variety of factors that have been found to influence mortality, including smoking, gender, education, marital status and disease, the researchers calculated how each BMI trajectory was related to mortality rates. In both generations, those who started at normal weight and moved to being overweight later in life — but never obese — were the most likely to survive. Those who stayed at normal weight throughout life were the next most likely to survive, followed by those who were overweight but stayed stable and then those who were at the lower level of normal weight. In the older generation, those who were overweight and lost weight came next. The least likely to survive were two trajectories involving those who started as obese and continued to gain weight.

BMI trajectory in younger generation worrying

While both generations showed the same basic results, the researchers discovered some worrying trends in the younger cohort. The higher BMI trajectories in the younger generation tend to shift upward at earlier ages relative to their parents. Moreover, the proportion of the sample in higher BMI trajectories systematically increased from the parental generation to their children. But fortunately, medical advances made through the years mean that people are more likely to survive with obesity now than in the past

Even though the mortality risks associated with obesity trajectories have decreased across the generations, their contributions to population deaths increased from 5.4 per cent in the original cohort to 6.4 per cent in the offspring cohort. That’s because more people are in the obesity trajectories in the offspring cohort.

(With inputs from Agencies)

Published : February 5, 2021 10:40 am

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