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Why a little bit of fat matters. Prepare to be offended.

            In the past couple of posts I have argued that one cannot be fit and fat and that the research that appears to support the idea that excess body fat is not a detriment to longevity has serious flaws. Obesity is a markedly complex issue that can hardly be discussed in depth in a blog as brief as this one but some recent news helps to clarify at least one issue, the high mortality of SARS-CoV-2 in obese persons and how that might apply to other health matters.

            Some caveats, comments and concessions: (1) the terms “overweight” and “obese” are somewhat arbitrary but necessarily so in order to form baselines in research. (2) Body Mass Index (BMI) is of limited usefulness for reasons noted in earlier Carvings blogs. (3) All body fat is not the same; subcutaneous fat is not by itself associated with diseases such as coronary artery disease, stroke, cancer and type 2 diabetes but visceral fat, which is interspersed within the abdomen is. (4) Genetic factors play a large role in the interaction between fat stores and disease. (5) Skeletal size and body type blur the definition of “overweight,” which demographers generally consider to be ten pounds over the actuarial norm but that is somewhat arbitrary.

            In an article at www.medscape.com posted today, November 1, 2021, researchers from Stanford University analyzed autopsies of persons who died of COVID-19 and noted: “Infection of fat cells led to a marked inflammatory response, consistent with the type of immune response that is seen in severe cases of COVID-19.” The authors note that this may explain why obese persons do so poorly during infection with this virus.

            Perhaps this observation and a hypothetical illustration will explain why persons who have only a little more body fat than nature intends are not as healthy as they like to think they are.

            Let’s use the example of identical twin men (A and B) – which eliminates genetic influences — age 50 who live in adjoining homes. Both are engineers, work in the same company, have similar pastimes and physical activity and are married to twin sisters. Their diets are identical and the sisters are excellent cooks, follow the same recipes and like the same foods. However, Wife B has a talent for making her dishes look more appetizing so that Husband B eats just a little more than Husband A. Not much more, mind you, only about 7 or 8 calories per day more that he doesn’t burn off with exercise. (That’s a little less than a single bite of a banana or not even one-third of a teaspoon of sugar.) Unfortunately those few calories have allowed Husband B to gain a little less than one pound a year over 30 years so that he now weighs 20 pounds more than Husband A. (See below for the math.)

            What do those 20 pounds consist of? The answer is fat, most of which is (relatively harmless) subcutaneous fat but some is the nasty visceral type. That’s why Twin B, to his chagrin, has a waist size two inches or so bigger than Twin A. Hardly noticeable, right? But as noted above, visceral fat produces inflammatory chemicals that are associated with coronary artery disease, stroke, cancer and type 2 diabetes as well as several autoimmune diseases such as rheumatoid arthritis and multiple sclerosis.

The conclusion: Twin B is not as healthy as Twin A. Not by a lot, and if he exercises regularly, he might live to a ripe old age. Maybe.

I’m quite aware that there is a gradation between normal, overweight and obese. The latter two categories, though not precisely defined, comprise more than 75 percent of the U.S. population. Of the fifteen leading causes of death in the U.S., most are directly or indirectly linked to obesity.

Curious about the math? Seven calories per day for 365 days equals 2555 calories. Over 30 years that’s 76,650 calories, equivalent to 21.3 pounds of fat. Isn’t that a bummer!