Reducing the waistline is a common goal, even among those who watch their diet and exercise.

Sometimes, regardless of weight loss amount, the midsection still doesn’t appear toned and flat.

Frustrating? Yes.

Logical? Unfortunately, also yes.

It all has to do with the different types of fat.

First, there’s subcutaneous fat, the fat that you can pinch. It sits just under the skin. Examples are the “love handles” on the sides of the waist, or the “pooch” that so many women describe in the lower abdominal area.

A sumo wrestler is a good illustration of subcutaneous fat. These athletes have very high amounts of subcutaneous fat (easily seen) and very little deeper internal abdominal fat. Subcutaneous fat accumulates slowly over time and can be very hard to get rid of once it is stored.

This second type of fat is visceral fat. It lies deeper within, wrapping around the internal organs. An illustration of visceral fat is the “potbelly,” which is round, hard to the touch and typically quite large in relation to the rest of the body. Here the abdominal muscles are actually being stretched tightly over the deeper layer of fat as it pushes the organs outward. Visceral fat is very easily stored, but also easily released.

Numerous studies have shown that subcutaneous fat presents substantially less health risk than visceral abdominal fat. When visceral fat is released into the bloodstream, it often ends up clogging coronary arteries and can lead to high blood pressure, elevated cholesterol, diabetes and other problems.

Excess fat is deposited differently from person to person depending on factors such as heredity, gender and age.

Women, for example, may have a body type whereby they store most fat in the hips, thighs and buttocks. Others store the majority of fat around the middle, with less in the upper and lower limbs.

Men tend to have greater visceral fat than women, and women with higher amounts of the stress hormone cortisol tend to have higher amounts. Visceral fat increases with age in men and women, and in lean and overweight individuals, but the percentage of the increase varies.

Sometimes, belly fat is confused with bloating, which can make an otherwise normal-looking waistline look distended. It’s often triggered by what we eat and drink, including sugar, high-sodium foods, refined carbs, processed meats, carbonated drinks, soda and alcohol.

One of the best ways to keep track of body fat levels is by measuring your waistline. Use a cloth tape measure and put it around the widest part of your waist (typically at or just below the navel). Record your number and re-measure every month. A waist size of 40 inches or more for men and 35 inches or more for women is considered high-risk.