Monday, November 30, 2009

Understanding Adipose tissue (body fat, depot fat)


Fat storage is A specialized function of adipose tissue, and it represents The major fuel depot of the body; it is as Essential to normal function as any other tissue. Body fat serves other important functions: It insulates The body against low environmental temperatures And serves as a shock absorber. Typically, fat Stored in adipose tissue represents 15 percent to 20 Percent of men’s weight and 20 percent to 25 percent Of women’s average weight. Women usually Have more fat than men because fat is an important Energy reserve during pregnancy and lactation. Adipose tissue synthesizes fat after a high carbohydrate Meal in response to the hormone INSULIN. During FASTING, STARVATION, or STRESS, a second Hormone EPINEPHRINE (adrenaline) signals ADIPOCYTES (fat cells) to break down stored fat into FATTY ACIDS, which are released into the bloodstream. They are rapidly absorbed and oxidized for energy By muscles. In contrast, the brain relies on blood Sugar to meet its energy needs.
The fact that an adult can consume approximately Two pounds of food a day (or 700 pounds of Food a year) with only small changes in body fat Indicates how well the body regulates weight when The calorie intake matches the total body requirements. Of course, common experience suggests that Body fat can increase. For example, fat accumulation Often accounts for the weight gain of middleaged Americans. Older people tend to EXERCISE less And the metabolic rate slows with aging. An individual’s Optimal body fat at any age depends upon Many factors, including inheritance, body build, Sex, and age. Standard HEIGHT/WEIGHT TABLES or the BODY MASS INDEX can be used to estimate an appropriate Body weight for an individual.
Excessive body fat is not healthy for many reasons.
OBESITY carries with it the increased risk of CARDIOVASCULAR DISEASE, HYPERTENSION, and some Forms of CANCER. It is interesting to note that the Distribution of body fat plays a role in defining the Risk for heart disease. Abdominal fat (the “spare Tire” profile) carries a greater risk for cardiovascular Disease than fat accumulated around hips and Thighs (the “pear” profile).
The general approach to losing fat stored in adipose Tissue is exercising and eating low-fat, highadipose Fiber meals, while decreasing caloric intake. Dieting Without exercise decreases muscle mass (not desirable) As well as the fat in adipose tissue, and the Weight regained after a crash diet is mostly fat (also Not desired). Cycles of dieting and not dieting also Cause loss of muscle mass. Muscle burns more ENERGY per pound than fat, so DIET cycling may Increase the difficulty of losing weight permanently. The number of fat cells in adipose tissue—
The storage bags themselves—cannot be lost by Dieting or exercise. The only way to lose fat cells of Adipose tissue is by LIPOSUCTION, a surgical procedure.

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