Carvings October 15, 2021
In the news
Fit and fat – missing the point – again!
Two weeks ago we wrote about about the misleading claim that one can be overweight or obese and be fit at the same time. Although carrying extra weight does not preclude the possibility of being free from the immediate risk of heart attack or stroke, or not having the markers of type 2 diabetes, longer follow-up studies uncover the dangers of extra weight in later years.
In just the past few days, on October 12th, another such misleading article appeared in the San Diego Tribune, a reprint of an item that was published in the New York Times. I am no expert in human metabolism, obesity or type 2 diabetes but some of the errors made in these articles should be obvious to anyone with a minimal education in these areas.
I remain puzzled about the overwhelming reference to the BMI (Body Mass Index) in so many studies. The BMI was devised more than 150 years ago by a French demographer who applied this tool in the analysis of populations. The BMI was never intended to be applied to individuals and I explained why, in detail, in the October 1st post.
Of the several articles that I have reviewed, the concept of Normal Weight Obese has not been addressed. Simply stated, a person whose weight is normal according to standard actuarial tables but whose level of body fat exceeds normal is considered NWO. In a study from a major medical center, twenty percent of women whose weight was normal by the usual standards were carrying extra body fat. The scale says that they are normal but the tape measure does not; they almost always have large waists, indicating the presence of visceral fat. A personal anecdote illustrates the problem. At a book signing at my alma mater – my 50th college reunion – a classmate came by and said “Phil, life just isn’t fair. I weigh the same as I did when you and I graduated 50 years ago but I have diabetes.” I had to bite my lip to keep from saying “You might weigh the same, but you’re not shaped the same.” In that half-century he lost muscle mass but replaced it with fat. Since fat takes up more space than muscle does, he needed a bigger belt. Further, muscle burns sugar but fat does not.
The article that argued that being overweight or obese can allow a person to remain healthy cited a grossly misleading reference. Persons undergoing liposuction with the removal of several pounds of fat had no improvement in their markers of heart disease. Of course not! Subcutaneous fat is not associated with heart disease and stroke but visceral fat – that which accumulates around the loops of intestine and that is overwhelmingly associated with cardiovascular disease, is left in place during fat removal.
The authors of that misleading study gave another example that they claimed “underscored the futility of workouts for weight loss.” Among women who walked 30 minutes a day three times a week: “After 12 weeks a few of them had shed some body fat, but 55 percent of them had gained weight.” Ninety minutes of walking in a week is a paltry figure; hunter-gatherer women are documented to walk an average of nine miles a day, often carrying an infant as well as the day’s harvest. Please!!
Also cited was the claim that losing weight does not lower the risk of heart disease, stroke or early death. Examples included the loss of up to 5 percent of body weight among exercisers. Unnoticed is the fact that a 250-pound person who loses even 25 pounds – ten percent, not five – is still grossly overweight and likely to have type 2 diabetes and heart disease.
In summary, carrying excess weight is detrimental to health and there are hundreds of well-conducted studies that show that this is so. It’s correct that exercise by itself leads to little weight loss but it does increase muscle mass, helps to control blood sugar levels and reduces the risk of heart disease and stroke.
You probably already know the difference between aerobic and resistance exercise, but most people that I talk to don’t do both! That’s unfortunate because nature has programmed our bodies to have both – every day. Luckily, we can get by very well by exercising about 4 or 5 days a week, provided that it’s varied and that each session lasts 30 minutes or more.
There are plenty of forms of aerobic exercise. Heck, even pushing around a vacuum cleaner for 45 minutes counts! So does yard work – which might also involve some resistance exercise. Walking, biking, swimming and tennis are great. (Sorry – golf is just so-so!) The important point is that we need to do aerobic exercise to keep our heart and lungs in good shape, and resistance exercise that will work every muscle group at least a couple of times a week to maintain balance and bone strength, as well as give both our immune system and our brain a boost.