Sugar, Starch, and Beer Belly

Does overeating make us fat?  No.  Fat makes us overeat.

This is a key theme in Gary Taubes book, "Why we Get Fat".  The cycle of being overweight starts with hormones.  Hormones set the body's target level of fat.  Not just for a few people with diabetes or other upsets.  Hormones set the fat target for every person or animal at any point in their lives.

Once the target for fat is set, if the target is set high--if the body decides to have a lot of fat--the body will feel hungry until we eat enough to maintain that fat.  Fat, then, causes overeating.  This defies the conventional wisdom that overeating causes fat.  Quite the opposite.

What if we ignore the root cause of fat--hormonal imbalance--and try to "burn" the fat with exercise?  According to Taubes, research shows this almost never works.  The exercise literally causes us to "work up an appetite".  The hormones are still calling the shots, ensuring that we eat again to return the fat to target.  We either eat more or get lethargic to conserve whatever calories come in so that they can be redirected to the body's goal of staying fat.

Taubes cites many studies, but the ones I found most compelling involved laboratory rats.  If their hormones were manipulated to set a high target for body fat, they did whatever was needed to build up this fat.  If their calories were restricted, first they would get more and more sedentary so that calories would go to building fat.  Further calorie restrictions would cause the rats to preserve fat at the expens of  weak muscles and bones, smaller brains, and weaker hearts.  In a few experiments in which they were starved, they DIED fat.  Hopefully these cruel experiments are never repeated, but they do make a point.

So what to do about this?  The most important hormone to control, by keeping it at the lowest level possible, is insulin.  The only way to minimize insulin it to eat fewer carbohydrates.  The author shows tremendous research supporting the idea that low carb diets are by far the most effective way to reduce fat with a variety of health benefits.

Taubes book is a big part of the reason I started a low carb diet yesterday.