Dear Dr. Cutler,

I’m an overweight woman in my 60s and I’ve never had any luck in losing those unwanted pounds. I’ve always thought that all body fat was the same and that I’ve simply got too much of it. However, I recently heard there are many different types of body fat. If that’s true, would you please explain what they are?

—Mary Kate D.

Dear Mary Kate,

There are three types of human fat. Two kinds—structural and reserve—do not impact your weight even if your body has maximum amounts of them. It’s the storage fat that creates the unwanted pockets of fat, or obesity.

• Structural fat is like packing material because it surrounds your internal organs, gives support to arteries and makes your skin smooth and taut. It provides padding for the bones throughout your body, as well as under the bottoms of your feet.
• Reserve fat is found all over your body and is used only as “fuel.” Your body can draw on this fuel fat when the nutrients in your bloodstream fall below the needed level and your organs demand energy.
• Storage fat accumulates in specific unwanted spots such as the areas around your abdomen, hips, upper arms, buttocks, thighs and breasts. But unlike the normal reserve fat, this “problem” fat is not available to the body in a nutritional emergency. If you are obese and you attempt to lose weight by starving yourself, you will first lose reserve fat as fuel. When the reserve fuel is exhausted, you will start burning up structural fat. But your body will only give up storage fat as a last resort.

That’s why if you’re an obese person, you may feel weak and starved when you cut way back on calories. Although your face may look drawn, the problem areas—your belly, hips, buttocks, thighs and upper arms—show very little decrease in weight. Because you’re losing structural fat—the fat covering your bones—your skin wrinkles and you begin to look old and haggard.

So what causes your body to accumulate this hard-to-lose storage fat? The most prevalent culprit is the repeated and consistent ingesting of nutrient-poor, high-calorie food. Other reasons include a sedentary lifestyle or depression.

Depression often leads to watching too much television and eating unhealthy comfort foods. These comfort foods hit the pleasure centers of the brain, but are the least healthy and most obese-promoting foods available. And there are some cases of obese people who are psychologically attached to being fat. For example, someone who has been sexually or even emotionally abused may allow themselves to become overweight as a punishment and a way to avoid sexual intimacy.

Whatever the reason may be, identifying why you’re accumulating your storage fat is a big first step in controlling your weight instead of letting it control you.

All the best!
Michael Cutler, M.D.