Why, yes, I *am* fat, thank you for noticing. Did I mention that you smell funny?
New York Times medical writer and author Gina Kolata has just published a new book entitled “Rethinking Thin: The New Science of Weight Loss — and the Myths and Realities of Dieting”, and the NYT was so kind as to run this excerpt of her book today. The excerpt presents some of the research that makes the claim that genetics influence our ability to gain, lose and maintain weight to such an extent that it is almost impossible to control your weight through diet and exercise unless you do it constantly.
There is a reason that fat people cannot stay thin after they diet and that thin people cannot stay fat when they force themselves to gain weight. The body’s metabolism speeds up or slows down to keep weight within a narrow range. Gain weight and the metabolism can as much as double; lose weight and it can slow to half its original speed.
The scientists summarized it in their paper: “The two major findings of this study were that there was a clear relation between the body-mass index of biologic parents and the weight class of adoptees, suggesting that genetic influences are important determinants of body fatness; and that there was no relation between the body-mass index of adoptive parents and the weight class of adoptees, suggesting that childhood family environment alone has little or no effect.”
In other words, being fat was an inherited condition.
A new study conducted by Harvard Medical School finds that different kinds of body fat have different effects on a person’s overall health, according to this BBC story. Subcutaneous fat — the kind that Sir Mix-A-Lot loves — actually produces hormones called “adipokines” (literally, “fat movers”) that can increase metabolism and can aid in insulin receptivity, thus reducing the risk of diabetes. Visceral fat — the All-American Beer Belly — does not have any beneficial effect.
Another new study, this one conducted at the Karolinska Institute in Sweden, found that fat cells in the human body actually replace themselves over time, just like other cells. It was previously thought that this did not occur. (It has also recently been discovered that brain cells also replace themselves, which was thought to be impossible as well. Maybe that explains the large number of fat-heads in our society…but I digress…) Even in gastric-bypass patients, while the fat cells shrank, the number of fat cells in their bodies did not actually decrease. That ties in pretty well with the idea that your overall tendency toward obesity is genetic and your ability to maintain a lower weight (if you’re overweight like me) is hard to achieve.
At least, that’s my story and I’m sticking to it.
