Everyone has some body fat. Healthy levels of body fat actually improve a person’s health and appearance, but excess fat tends to increase the risk of poor health and is generally viewed as unattractive in most cultures. Excess fat accumulates in different areas from person to person, though some generalities can be made. Women tend to accumulate fat in the thighs and around the pelvis (hips, buttocks and the lower abdominal “pooch”); men are more likely to deposit body fat in their midsection, providing a visual cascade of fat over the restraints of stressed belts.1 This has given rise to the descriptive terms of apple- versus pear-shaped body types.
“Apples” can include both men and women, as is easily seen by taking a quick survey of the bodies shopping at any local mall.2 Often, central fat (another term used to describe abdominal fat, both visceral— surrounding the internal organs and subcutaneous— under the skin) accumulates due to a state described as glucose intolerance or insulin resistance.3 Glucose is the scientific term for sugar in its most common form. Glucose is in nearly every carbohydrate-containing food and is the main stimulus for insulin secretion. Most lean people are very efficient in dealing with glucose, using only the necessary amount of insulin to shuttle the sugar molecules into the muscle, liver or fat cells. Actually, nearly every cell in the body has receptors for insulin, but muscle, liver and fat cells are the main targets. However, some people become resistant to the insulin signal, so the pancreas releases more of the hormone into the bloodstream in order to dispose of the sugar influx from a meal. In some cases, insulin remains high, even when the person is fasting; others have normal fasting insulin but have to release a great deal more of the hormone when food is consumed. Fasting is the state of the body when one has not eaten for several hours. Most doctors look only at the fasting glucose level— some will check fasting insulin levels as well. Only recently has the importance of insulin release with a meal been realized. Yet, this is rarely checked, as it involves a more expensive and time-consuming process than a simple blood draw.

In order to measure insulin secretion after a meal, a patient has to undergo a glucose tolerance test (GTT). To perform a GTT, a patient must arrive in the fasted state, typically first thing in the morning. It is important that no food or caffeinated beverages have been consumed. Blood is drawn to measure insulin and glucose, and then a sugary drink containing exactly 75 grams of sugar is given. Insulin and glucose levels are checked at regular intervals and the lab values are plotted on a chart.4