Some people who quit smoking gain weight even if they watch their diets because moderate smoking helps the body burn fat, according to a recent study. But researchers were quick to warn that smoking shouldn't be considered a substitute for dieting. "Smoking, from a health point of view, is much more risky than weighing those extra few pounds," said Marc K. Hellerstein, a University of California at Berkeley professor and lead author of the study. Previous studies have shown that smoking increases metabolism, the process that turns the calories in food into energy. But Thursday's study was the first to show that smoking directly stimulates a process called lipolysis that frees lipids, or fats, from cells and spills them into the bloodstream. Some of the lipids entering the bloodstream are burned by the higher metabolism, but many of them are converted by the liver into fatty substances called triglycerides that contribute to clogging of arteries. The study was published in the Journal of Clinical Investigation.
