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Read “Survival Genes and You” an AAOS Ortho-pinon by Dr. Reznik

Read “Survival Genes and You” an AAOS Ortho-pinon by Dr. Reznik
Monday, October 15, 2018

In 2016, the New York Times published a review of scientist Dr. Kevin Hall’s six-year follow up study on the winners of “The Biggest Loser” TV show:

“It is frightening and amazing,” said Dr. Hall, an expert on metabolism at the National Institute of Diabetes and Digestive and Kidney Diseases, which is part of the National Institutes of Health. “I am just blown away,” he said about the resting calorie burn of these overweight individuals. “When it (the contest) ended, their metabolisms had slowed radically and their bodies were not burning enough calories to maintain their thinner sizes.”

As years went by after the conclusion of the show, the numbers on the scale climbed and the contestants’ metabolisms did not recover. They became even slower, and the pounds kept piling on.

“Mr. Cahill (winner of season 8 of NBC’s the biggest loser) was one of the worst off. As he regained more than 100 pounds, his metabolism slowed so much that, just to maintain his current weight of 295 pounds, he now has to eat 800 calories a day less than a typical man his size. Anything more turns to fat,” according to Dr. Hall.

These extreme cases seem to indicate that some people have an ability to cut their metabolism down to a minimum. The calculations are both shocking and simple. If the rate of calorie use is cut by only 500 calories per day, that translates to gaining one pound of fat per week, 52 pounds per year and 104 pounds in two years. Hence, these people may indeed have ‘superior’ metabolic control during perceived starvation.

Understanding the function of these ‘survival genes’ for calorie use and retention may be the new holy grail of the weight gain/loss problem for people in general. From this data, it is no wonder why people can rebound and regain their weight so fast after a harsh diet. Our ancestors’ calories required hard work, tracking animals for days, and a big meal may have only come once a month instead of every night. There were no big holiday parties, ice cream cakes, tailgating or mini-series to watch, never mind the classic all day 6,000-calorie feast of Thanksgiving. It seems to follow that our ancestors, the starving cavemen, had to be able to cut their metabolic rate during starvation just to survive.

For the over-weight person, diets that force severe starvation for fast weight loss almost always lead to a return of more weight once their metabolism drops and the diet stops. It may be a natural protective mechanism. This could be why some people’s weight seems to ‘yo-yo’ down then up, and most of the time to a new even higher weight. The gimmicky diets of liquids and one meal a day most likely do the same thing. On an extreme diet, our caveman ‘survival genes’ are called into action. Our metabolism drops, and we are ‘saved’ from starving to death.

One opinion is that diets of small frequent meals may, in theory, counteract this problem. Many of my patients tell me that when they start that type of program, they feel that they cannot eat as much food as the diet allows. It surprises them! Upping the food amount at first, in the slow, steady diets with frequent small meals, may well trick the body into believing it’s not starving. As many nutritionists may tell you, always start a diet with calorie level based on your current weight, not your final goal weight.

All of this leads to one more issue for those of us with ‘survival genes.’ Others judge many of us by our weight. Not understanding the metabolic gene issue makes this even more difficult. If the person with a weight issue has a far better metabolic design, a more efficient body and could survive extreme conditions far better than the rest of us, the weight problem may not be their ‘fault.’ They just don’t see the caveman starvation challenges in the modern world. It may well be that the combination of ‘smarter genes’ and drive through windows, oversized meals at restaurants, sugary drinks and addicting TV series are to blame. (Yes, worse yet, measured metabolic rates for TV watching can be lower than sleeping hence more weight gain in TV watchers.) These could be the best arguments for avoiding fad diets, having calorie counts on menus, taxing sugary drinks and promoting outdoor exercises.

The problem, as I see it, is cavemen with those survival genes never drove a car to the supermarket. They did not buy processed sugar products, eat dessert after each meal, or have 64 ounce sugary drinks along with a bag of potato chips while sitting perfectly still in a two hour movie. And, moreover, they never sat perfectly still for 6 hours binge watching Game of Thrones, The West Wing or The Real Housewives of New Jersey.