Wednesday, May 9, 2007

Gene Genies

Yo dog, check it out. (Sorry--too much American Idol and if you didn't recognize it, that was my Randy Jackson impression.)

There's a new book out within the past few days that I find quite interesting. It's called Rethinking Thin: The New Science of Weight Loss--and the Myths and Realities of Dieting, and is written by New York Times reporter Gina Kolata.

The New York Times ran an excerpt yesterday, and it's quite fascinating.

Basically it talks about some studies with which I was unfamiliar, and a few I'd heard of, studying the genetic link to obesity. I always knew it was strong--take one look at my family and that wouldn't be up for any debate. But it seems to be even stronger than I thought.

Now, I should have this caveat up front: I don't think genetics means losing weight is hopeless. It means losing weight will be harder for some people, and it means maintaining weight loss will be harder still. Study upon study has shown that most people who lose weight gain it back. Here's a big reason why.

Back in 1959, a Rockefeller University researcher named Jules Hirsch conducted a groundbreaking study on obese people. He wondered whether, when obese people lost a lot of weight, their fat cells shrunk or disappeared. He took eight people with lifelong obesity, put them on a 600-calorie liquid diet, had each of them lose on average 100 pounds, and then looked back at their fat cells. He was satisfied--the formerly obese folks' fat cells hadn't disappeared but they had shrunk to a "normal" size.

He sent them all on their merry ways, but then was horrified that they all regained the weight (duh, how many went back home to 600-calorie liquid diets). Anyway, they repeated the study and got the same results every time, but in subsequent studies also monitored diet, activity, psychiatric conditions, and metabolic rate.

Ding ding ding. Every obese person who lost weight measured metabolic rates comparable not with normally thin people but with people who were starving. They also had a psychiatric syndrome called "semi-starvation neurosis" that had been observed in people of normal weight who had been starved. Anxiety, depression, secreting of food, binging.

The excerpt in the Times notes other studies but the bottom line is this: there's an 80% chance that if your parents are obese you will be too. Is it impossible to lose weight? Of course not--there are so many of you out there who've lost lots of weight and have kept it off with a low-carb lifestyle, particularly.

But point is, you who have kept it off have also kept your weight on the front burner. As the book says, "there were a few who did not get fat again, but they made staying thin their life's work."

Which, I suppose, is one of the reasons we write blogs and read blogs and stay focused on weight and health issues. And because of the low carb diet's satiety factor, which is I think its biggest advantage of all, I wonder if that changes the equation any.

So many questions. What do you think?

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