胖瘦不在身材，节食还是锻炼？

    "Being thin doesn't automatically mean you're not fat," an AP report Thursday quoted Dr. Jimmy Bell, a professor of molecular imaging at Imperial College, London, as saying.

    Bell's team has scanned nearly 800 people with MRI machines since 1994 to find out where fat is stored in their bodies.

    Data show people who keep slim through diet rather than physical exercise are likely to have major deposits of internal fat.

    Doctors worry that thin people, without a clear warning signal, may falsely assume that they're healthy just because they're not overweight.

    "Just because someone is lean doesn't make them immune to diabetes or other risk factors for heart disease," said Dr. Louis Teichholz, chief of cardiology at Hackensack Hospital in New Jersey.

    Even normal Body Mass Index (BMI) scores cannot assure healthy levels of fat deposits inside.

    Of the women scanned by Bell and his colleagues, as many as 45 percent of those with normal BMI scores (20 to 25) actually had excessive levels of internal fat. Among men, the percentage was nearly 60 percent.

    Experts say there is no short-cut when it comes to being fit. "If you just want to look thin, then maybe dieting is enough," Bell said. "But if you want to actually be healthy, then exercise has to be an important component of your lifestyle."