Fat Genes - Is Obesity Genetic?
 My dad, who was obese, used to say that he didn't eat too much, he was just genetically and hormonally that way. The doctors laughed at him, but now that he's dead and gone, I'm reading that obesity is genetic. What do you think?
 Well, my dad tried the same line. We are not like orchids, getting fat on thin air and sunshine, are we? So, fat has to come from our food. The balance, though, is how much we utilize. Some folks are like Toyota Corollas and others are like Lincoln Navigators—not in their size, but in their metabolism. The Corolla goes farther on a gallon of gas. So, if you go farther on a donut than someone else, where do you think the excess "gas" is going to go? No it doesn't run out of your mouth B it sits on your seat or below your belt. Eating more than you use leaves the body nowhere to put the stuff than into fat.
But Dad was right in some ways. Studies on twins show that possibly up to 70 percent of a person's body mass may be genetically determined. This isn't a simple gene, but a complex interaction of many genes. The problem is that Americans on the whole are getting heavier, and our gene pool is not likely to blame for that. Exercise—or the lack thereof—is probably a major cause. The increased intake of high-fat, high-cholesterol fast foods is another. Metabolism does play a role in that a 60 year old male probably needs 950 calories per day less than he did when he was 20, yet he probably still eats—or wants to eat—like he did when younger. Muscle bulk decreases with age, and muscle is a major "fat-burner," so if you have less muscle, you will store more fat. Come on now — let's push some weights!
As for hormonal—yes, Dad was right, too, but his appetite still played a role. A hormone called leptin is believed to suppress appetite. Once body fat stores are enough, leptin levels are supposed to rise. Perhaps people with deficient leptin get fat? Sounds fantastic, but unfortunately it didn't pan out. Leptin deficiency is exceedingly rare. Perhaps people become leptin-resistant, like diabetics may be insulin-resistant, but no one knows for sure. No one is promising us pills containing leptin that will reduce weight any time soon.
So dear old Dad, I guess I've inherited your love of food and difficulty in pushing away from the table! (Nice try, wasn't it?!) |
