Did you know that overweight, active folks can actually be healthier than their thinner, inactive counterparts? And now, there is proof – magnetic resonance imaging, better known as an MRI – which create fat maps showing where people store fat. The whole concept of being fat needs to be redefined, says Dr. Jimmy Bell, professor of molecular imaging at Imperial College, London. Just because someone is lean doesn’t make them immune to diabetes or other risk factors for heart disease, says Dr. Louis Teichholz, chief of cardiology at Hackensack Hospital in New Jersey.

The key: exercise!

Perry is on the thin side, watching his diet to a degree, and his favorite activity is using the remote and a mouse. Occasionally he plays golf and walks the dog on sunny days. Maria is chubby, watches her diet to the same extent as Perry, but plays tennis three times a week, works out regularly, doing a combination of cardio and weights. According to the latest findings, Maria’s fat, unlike Perry’s, is stored primarily under her skin, and not concentrated around vital organs.

The theory is that internal fat disrupts the internal communication systems and that the fat surrounding the internal organs might be sending the body mistaken chemical signals to store fat inside organs such as the pancreas and liver which in turn, can lead to insulin resistance, type 2 diabetes or heart disease. Because of Maria’s activity, she stands a much better chance of burning off her internal, visceral fat. There is actually a term for people like Perry, who are thin outside and fat inside (TOFI’s). Researchers who scanned 800 patients with MRI machines that plotted internal fat maps found that as many as 45% of women and 60% of men with normal BMI scores (20 to 25) had excessive levels of internal fat! (BMI is a standard obesity measure that divides your weight by the square of your height) The worry is that being thin externally is not an indicator that you are not fat!

If you just want to look thin, then maybe dieting is enough, Bell says, but if you want to actually be healthy, then exercise has to be an important component of your lifestyle. So everyone! Listen up! Time to crank up your levels of regular activity regardless of weight or age! No more excuses! See you at the gym!

(Judit Rajhathy, Change of Pace Fitness Center, Ajijic Mexico & author of Canadian best seller Free to Fly: a journey toward wellness)