Fat is fat—right? Wrong!
Actually depending on colour and location, fat can either be good or bad.
Brown fat (good) is present more in infants, but some amount is present on the upper chest and neck in adults too. It has more mitochondria (the chemical factories inside our cells), capillaries, and iron content. It is thus more active --generating more oxygen and heat, and burning up more calories.
White fat (bad) on the contrary is a store house of harmful saturated fats.
Irisin is a protein hormone that in experiments on mice converted white fat into good brown fat.
People, who jog, play vigorous games and indulge in other aerobic activities, have higher levels of irisin and consequently more of brown fat. They resist weight gain even on a high fat diet and do not develop diabetes.
Visceral fat (bad)
Abdominal fat can be ‘visceral fat’ that surrounds the organs in the abdomen and found mainly in deprived races that have suffered famines in past (South East Asians, Africans and South Americans). An excess of visceral fat causes central obesity, or "apple shape”, in which the abdomen protrudes excessively.
Visceral fat secretes a group of hormones called adipokines that impairs insulin
action, thus raising blood sugar, causing obesity, heart disease, dementia and even
6 volunteers from Joslin Diabetes centre in USA had their visceral fat removed by major surgery and after 6 months there was a 60-80% increase in insulin sensitivity, which we know is a good thing to happen.
Diagnosing Visceral obesity
This can be done by---
Subcutaneous fat (good)
Subcutaneous fat is fat under the skin. It is more evenly distributed in the abdomen, hips and buttocks giving the abdomen a ‘pear shape’. It improves insulin sensitivity and protects us from diabetes, high blood pressure and heart attacks. People undergoing liposuction, (removal of fat from the abdomen) are actually creating trouble for themselves; because in striving for a trim figure, they are removing the good subcutaneous fat.
SUMO wrestlers have more of this kind of fat, so in spite of seeming morbidly obese, they are healthy.
There are 6660 genes in the body out of which 20 ‘good fat genes’ are in the subcutaneous tissue -- and 20 ‘bad fat genes’ in the visceral area.
What the future holds
We can change white fat to brown with exercise and Irisin injections, and remove bad visceral fat (surgically and by switching genes) to become ‘fat but fit!’