With two in every three people in our world considered overweight or obese, it is no wonder why so much attention -and concern - is paid to our ever-expanding waistlines. But for the one-in-three people who fall into the `healthy weight' category, don't think you are automatically safe and healthy because you don't appear to be overweight.

New studies reveal that internal fat surrounding major vital organs like the heart, and liver - invisible to the naked eye - could be as dangerous as the more obvious external fat that bulges underneath the skin in overweight people. 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.

These much admired slim people have been found to be hiding fat inside their bodies and that unseen fat can be every bit as unhealthy and carry the same health risks as if it were bulging over their belts. Experts have long known that overweight, active people actually can be healthier than their skinny, inactive and sedentary counterparts.

It is now understood people can still be of 'normal' weight and do not eat enough overall to become overweight but their diets can be made up of too many high fat and high sugar foods. If they are not highly active or perform a regular exercise program they are not burning off the excess calories as energy so it can be stored inside the body becoming a ticking time bomb.

This type of fatness is dangerous because there is no outward indication that it is there so the health risks are not apparent. Unlike the ever-expanding waistline we can see, there is no barometer to signal you have too much internal fat. The clothes still fit okay; you can see your feet, you weight the same as you always have so it is easy to think you do not need to worry about your health. People who are slim and trim just assume they are healthy and that might not be so.

Slim people can also assume that the only benefit that can be achieved from exercise is weight loss which they don't need therefore it can be of no benefit to them. But this is not the case. Everyone regardless of age, body shape or weight needs to exercise to stay strong fit and healthy.

A proper exercise program that includes strength training exercise benefits extend to things like stress reduction, heart health, all over body muscle and bone strength, mental health and wellbeing, the stimulation of youthful hormones and a biggie - disease risk reduction. It makes no sense that a slim person wouldn't benefit from these things.

The good news is that internal fat can be easily burned off through proper exercise that speeds up your metabolism (your body's engine). This is the first type of fat to be burned up for energy so even though you can't see the improvement on the bathroom scales it will be happening on the inside reducing those health risks.

To further reduce this stored fat you also improve your eating plan to include 4-6 small meals spread throughout the day that each contains a protein source. These small meals will also be stoking up your metabolism to stop the likelihood of this internal fat being stored in the future.

So, there is more to being healthy than just being slim. To be truly healthy proper exercise has to be an important component of your lifestyle to help you achieve the ultimate in weight loss ? becoming 'skinny' on the inside.