Men are generally at higher risk for cardiovascular disease than women, and one of the reasons may be their higher percentage of abdominal fat. The recommendation for a healthy body circumference measured around the belly button is less than 40 inches for men and less than 35 inches for women. If your abdomen is larger than that, your risk for cardiovascular disease and other conditions increases.
Where does fat come from?
Fat comes from foods we eat, particularly animal and dairy products. Every time you eat a food with fat, the fat gets digested by bile and pancreatic enzymes in the small intestine. The resulting fatty acids are then absorbed and transported to the liver, where essential nutrients are removed. Then the rest is wrapped up and packaged together with proteins to form chylomicrons, so that it can travel through the bloodstream to all the organs and cells that need it.
If you eat more fat than your body needs, it either gets stored in the arteries of your heart (which is not a good thing), in your liver (which can give you a fatty liver and is also not a good thing), or in the adipocytes on your hips, thighs, buttocks, or abdomen (another not-so-good thing). Adipocytes love to store fat. They gobble it up like there’s no tomorrow, and with the ample amount of inexpensive, fatty foods available in our society and the copious amounts many of us eat, most adipocytes in the United States are well-fed, happy buckaroos.
When you fill an adipocyte with fat, it gets larger, just as a balloon gets larger when you fill it with air. Contrary to popular belief, however, when adipocytes get too big, they do not divide and multiply to form more adipocytes. Instead, the adipocyte grows like an overinflated balloon until it reaches a maximum diameter of approximately 15–20 microns, then it sends a biochemical signal to adjacent, immature preadipocytes in the body to begin storing the extra fat. These preadipocytes then grow larger, too, and when they become fully mature, plump adipocytes, you gain more body fat. The larger your adipocytes become, the higher your percent body fat will be.
During childhood and into puberty, both the number of mature adipocytes and the size of the adipocytes increases. It is believed by many scientists that the number of adipocytes stays fairly stable after adolescence and that instead of an increase in the number of adipocytes during adulthood, the mature adipocytes enlarge in size, stimulating the preadipocytes to get bigger too. There is some recent evidence to suggest that the number of adipocytes can also increase during adulthood, but whether we increase our body fat through increases in the number or the size of the adipocytes, one thing is certain: Excess fat intake leads to increases in body fat.
It’s not just fatty foods that make us fat, however. Whenever we eat excess calories, we stand a good chance of gaining fat. Excess carbohydrate that isn’t used by the body may be converted to fat, and then it too gets stored in the adipocytes. However, some very interesting research has recently suggested that not as much carbohydrate as was once thought gets converted to fat. Scientists are looking carefully at the role of carbohydrate and its role in making people gain excess fat, but for now, it’s believed that excess calories in any form causes fat gain.
Remember that fat cells are active glands. Not only do they secrete important proteins, enzymes, and hormones, but they also secrete fat. They secrete it because it’s a valuable fuel for muscles. It’s packed with energy, providing nine calories per gram, whereas a gram of glucose contains only four calories. A calorie is a unit of energy contained in our food that provides fuel for our muscles, just like gasoline provides fuel for an automobile. Think of muscle as the engine in your body, and think of fat as high-test fuel, providing more than twice the amount of calories or energy as a gram of glucose. This means that you can go more than twice as far on a gram of fat as you can on a gram of carbohydrate. The catch is learning how to get the fat to the muscle so that it can be burned for energy.