How booze builds a beer belly's bulk
BOSTON (AP) -- At last, science has found an explanation for one of the obvious effects of drinking too much -- the beer belly.
Swiss researchers report that when people drink alcohol, their bodies burn up fat much more slowly than usual. And any fat that isn't burned is stored in the paunch, the thighs or other places where people tend to put on weight.
The study suggests it isn't just the calories in alcohol that make it fattening. It's the way alcohol throws off the body's normal disposal of fat in the diet.
"This is one good explanation of why people get fat drinking alcohol," commented Dr. Clifton Bogardus of the National Institutes of Health.
The study was based on an experiment in which people were put on a diet that included about 3 ounces of pure alcohol a day. This much alcohol -- about six shots of whiskey or six beers -- reduced their bodies' burning of fat by about one-third.
The study, directed by Dr. Paolo M. Suter of the University of Zurich, was being published in Thursday's New England Journal of Medicine.
The research is one more piece of a larger idea to emerge from recent investigation of how people get fat or stay thin. It seems that fat is what makes people fat.
When people eat extra carbohydrates -- sugar or starch -- they tend to burn most of it, adding little to their girth. But the body burns extra fat sparingly and instead saves it away.
Of course, not everyone who drinks gets a spare tire. It depends on what they eat. Beer guzzlers and whiskey drinkers who subsist on hamburgers and potato chips will almost certainly put on pounds, while vegetarian wine sippers do not.
The Swiss study found that alcohol suppresses the body's already-stingy disposal of fat. Just why this happens is unclear. The body may simply prefer to burn alcohol first, or alcohol may have some other effect on metabolic processes in the liver.
The finding "points to the fact that energy balance over the long term has a lot more to do with fat balance than anything else we eat," said Bogardus. "The main way to stay thin is not to eat fat."
The study was conducted on eight healthy men during two sessions. In one, alcohol made up 25 percent of their calories, but their total daily calories did not change. In the other, they drank enough alcohol to increase their daily calories by 25 percent.
On both diets, the men's bodies burned about one-third fewer fat calories when they drank alcohol.
The study reached one modestly positive conclusion: People who substituted alcohol for other food but did not increase their daily calories actually burned up slightly more calories over all than when not drinking. The reason appears to be that alcohol boosts the metabolism.
This finding provides a strategy for drinking without putting on flab.
"If somebody wants to drink socially and avoid gaining weight, he should have a substitution strategy -- substitute fat calories for alcohol," said Suter.
However, this is hard to do. And Bogardus noted that people doing this might still put on extra fat, even if they actually weigh less.
"You'd end up with a slightly different body composition," he said.
The study found that while on the alcohol substitution diet, people burned up 875 fat calories, instead of their normal 1,291 fat calories. They also burned slightly less carbohydrate, a bit more protein and all of the 680 alcohol calories they consumed each day.
AP photo BEER BELLY BLUES: A beer drinker displays the visible effects of longtime indulgence as he poses in Boston Wednesday. Science has found an explanation for the beer belly.