It isn’t exactly news to say that obesity can shorten a person’s lifespan, but a new study in the Lancet suggests that obese men are dramatically more likely than women to die before age 70.
The study covered nearly four million individuals across the globe, both normal weight and obese. It was found that, among normal-weight individuals, the rate of dying before age 70 was 19% for men and 11% for women. Among obese individuals, the rate jumped up to 30% for men and 15% for women.
The research design wasn’t capable of making an assessment about why obesity seemed to shorten men’s lifespan more than women’s, but some theories were made based on past knowledge. Prior studies have found, for instance, that obese men are more insulin resistance, liver fat, and diabetes risk than women. The fact that obesity has a strong link to risks for heart disease, stroke, cancer, and other health ailments is also potentially involved, though how this presents across genders is not specified.
Since excessive weight gain poses a higher risk of early mortality for men, weight loss is theorized to improved longevity in men better than women. Losing about 10% of one’s body weight could improve a women’s chance of living to age 70 by 10%, but a man’s by 20%.
Although obesity has been linked to numerous health problems and risks of mortality, this link has not always been direct or potentially clear. The link between obesity and mortality is regularly challenged, in part due to some limitations of prior research. This new study, which is published in The Lancet, sought to overcome these limits by pooling data from 239 prior studies across Europe, North America, Australia and New Zealand, and elsewhere. The associations between weight gain, obesity, and shortened lifespan was consistent across each continent and supports the use of anti-obesity strategies across a wide number of populations.
“Body-mass index and all-cause mortality: individual-participant-data meta-analysis of 239 prospective studies in four continents,” The Lancet, 2016; http://dx.doi.org/10.1016/S0140-6736(16)30175-1.