Or at least, the vast majority of us are, according to a recent re-definition:
Obesity rates in the United States may increase dramatically under a new definition introduced earlier this year by the Lancet Diabetes and Endocrinology Commission.
Researchers at Mass General Brigham discovered that applying the updated criteria—which expands beyond the traditional body mass index (BMI) to include measurements of body fat distribution—raised obesity prevalence from around 40 percent to approximately 70 percent among more than 300,000 participants. The increase was especially notable among older adults. The study also revealed that many of the newly classified individuals faced a greater likelihood of negative health outcomes.
Who’s celebrating? The makers of diet drugs and the purveyors of diet programs.
It’s all very odd – particularly since there’s also been evidence that being somewhat overweight – even by the old definition – is somewhat beneficial for the elderly:
In fact, the nationwide study found that people who were slightly overweight in their 50s but kept their weight relatively stable were the most likely to survive over the next 16 years.
They had better survival rates than even normal-weight individuals whose weight increased slightly, but stayed within the normal range.
There are other studies that say something similar:
… [N]umerous studies suggest that carrying some extra weight can sometimes be protective in later life. For people who fall, fat can serve as padding, guarding against fractures. And for people who become seriously ill with conditions such as cancer or advanced kidney disease, that padding can be a source of energy, helping them tolerate demanding therapies. …
Experts are more concerned about a lack of activity in older adults who are overweight or mildly obese (a body mass index in the low 30s) than about weight loss. With minimal or no activity, muscle mass deteriorates and strength decreases, which “raises the risk of developing a disability or a functional impairment” that can interfere with independence, said John Batsis, an obesity researcher and associate professor of medicine at the University of North Carolina School of Medicine in Chapel Hill.
Weight loss contributes to inadequate muscle mass insofar as muscle is lost along with fat. For every pound shed, 25% comes from muscle and 75% from fat, on average.
Since older adults have less muscle to begin with, “if they want to lose weight, they need to be willing at the same time to increase physical activity.” said Anne Newman, director of the Center for Aging and Population Health at the University of Pittsburgh School of Public Health.
Ideal body weight may be higher. Epidemiologic research suggests that the ideal body mass index (BMI) might be higher for older adults than younger adults. (BMI is a measure of a person’s weight, in kilograms or pounds, divided by the square of their height, in meters or feet.)
One large, well-regarded study found that older adults at either end of the BMI spectrum — those with low BMIs (under 22) and those with high BMIs (over 33) — were at greater risk of dying earlier than those with BMIs in the middle range (22 to 32.9).
Older adults with the lowest risk of earlier deaths had BMIs of 27 to 27.9. According to World Health Organization standards, this falls in the “overweight” range …
And then, to top it all off, there’s this seeming paradox:
Deficiency of the gene melanocortin 4 receptor (MC4R) is linked with obesity among adults. A recent study has found that the same deficiency also leads to surprising outcomes such as reduced risk of heart disease, lower cholesterol, and triglycerides. These results contradict the well-established correlation between obesity and cardiovascular diseases.
The researchers scanned the genetic profiles of 7,719 children from the Genetics of Obesity Study (GOOS) cohort. They identified 316 probands—first person in a family to draw medical attention to a genetic disorder—and 144 adult family members with obesity due to loss-of-function (LoF) MC4R mutations.
Even after adjusting for weight, these individuals showed better blood pressure profiles and cardiovascular health when compared to 336,728 controls from the UK Biobank.
The gene defect ordinarily causes severe obesity, and I don’t think it’s all that common even in that population. So unless you’re very obese I don’t think there’s any chance you have it.
I think the issue of weight and health is quite poorly understood – and that includes why some people can eat a lot and be thin, and vice versa. Except for the new weight-loss drugs – and who knows how they affect health long-term – it’s very hard for most people to lose weight and keep it off.

