Thin people may actually be fat inside

Since 1994, Bell and his team have scanned nearly 800 people with MRI machines to create 8220;fat maps8221; showing where people store fat. According to the data, people who maintain their weight through diet rather than exercise, are likely to have major deposits of internal fat, even if they are otherwise slim. 8220;The whole concept of being fat needs to be redefined,8221; said Bell, whose research is funded by Britain8217;s Medical Research Council.

Without a clear warning signal 8212; like a rounder middle 8212; doctors worry that thin people may be lulled into false security, assuming that because they8217;re not overweight, they8217;re healthy.

8220;Just because someone is lean doesn8217;t make them immune to diabetes or other risk factors for heart disease,8221; said Dr Louis Teichholz, chief of cardiology at Hackensack Hospital in New Jersey, who was not involved in Bell8217;s research.

Even people with normal Body Mass Index scores 8212; a standard obesity measure that divides your weight by the square of your height 8212; can have surprising levels of fat deposits inside. Of the women scanned by Bell and his colleagues, as many as 45 per cent of those with normal BMI 20 to 25 actually had excessive levels of internal fat. Among men, the figure was nearly 60 per cent.

Relating the news to what Bell calls 8220;TOFIs8221; 8212; people who are 8220;thin outside, fat inside8221; 8212; is rarely uneventful. 8220;The thinner people are, the bigger the surprise,8221; he said, adding the researchers even found TOFIs among people who are professional models.

According to Bell, people who are fat on the inside are essentially on the threshold of being obese. They eat too many fatty, sugary foods 8212; and exercise too little to work it off 8212; but they are not eating enough to actually be fat. Doctors are unsure about the exact dangers of internal fat, but some suspect it contributes to the risk of heart disease and diabetes. The internal fat, they say, disrupts the body8217;s communication systems. The fat enveloping internal organs might be sending the body mistaken chemical signals to store fat inside organs like the liver or pancreas. This could ultimately lead to insulin resistance, type 2 diabetes, or heart disease.

Experts have long known that fat, active people can be healthier than their skinny, inactive counterparts. 8220;Normal-weight persons who are sedentary and unfit are at much higher risk for mortality than obese persons who are active,8221; said Dr Steven Blair, an obesity expert at the University of South Carolina. The good news is that internal fat can be easily burned off through exercise or even by improving diet. When it comes to being fit, experts say there is no short-cut. 8220;If you just want to look thin, then maybe dieting is enough,8221; Bell said. 8220;But if you want to be healthy, then exercise has to be an important component of your lifestyle.8221;