Body fat - we all need it in the right amount
By: Dan Palmquist, M.D.
Body fat isn’t a favorite phrase or topic for many who struggle with weight gain and weight loss. But, while body fat may have a bad reputation, it is one of the basic components that make up the structure of the body. It serves a number of important purposes and none of us could get along without it.
The technical term for body fat is adipose tissue and there are two types of it in the body: white fat (which includes subcutaneous and visceral fat) and brown fat.
A certain amount of white fat is essential for normal, healthy functioning. In men, essential fat is equals about three percent of body weight, while women have a higher level – about 12 percent. We all need the essential amount of body fat and then some. Having less is unhealthy and can lead to illness or chronic fatigue.
Beyond essential fat, it is also desirable to have some extra “storage” fat. For men, healthy levels of white (essential and storage) fat range from eight to 24 percent, depending on age. For women the range is 21 to 35 percent. Too much storage fat equals being overweight or obese.
White fat is much more plentiful than brown fat. A 150 pound person might have 20 or 30 pounds of white fat as compared to two or three ounces of brown fat. White fat stores excess calories (energy) so they can be used when needed and it releases hormones that control metabolism. It also cushions and insulates the body and organs.
Subcutaneous fat is located directly under the skin and compromises about 80 percent of your total body fat. It can be measured with a skin-fold calipers to estimate total body fat. Common spots for subcutaneous fat accumulation are on the hips, thighs and stomach. It builds up slowly over time and can be difficult to shed once it is stored.
Visceral fat surrounds internal organs inside your abdomen. If visceral fat accumulates it can interrupt the regular function of your organs. From a health perspective, it is more dangerous than subcutaneous fat. Along with subcutaneous fat, it can contribute to a widening midsection often described as belly fat. Abdominal fat is viewed as a bigger health risk than hip or thigh fat. In general, women with a waist circumference more than 35 inches and men with more than 40 inches are carrying too much visceral fat, putting them at increased risk for insulin resistance, type 2 diabetes, heart disease, stroke, certain cancers and dementia.
Brown fat, which is sometimes called the “good” fat, gets its color from high-density iron-containing mitochondria in its cells. Brown fat helps generate body heat and is more concentrated in infants, making up about five percent of an infant’s body weight as compared to adults where it makes up much less than that.
It used to be thought that brown fat disappeared completely by adulthood, but that’s not always the case. Some adults have brown fat in small amounts in the upper back, side of the neck, the dip between the collarbone and the shoulder and along the spine. Younger adults tend to have more than older adults; lean adults tend to have more than those who are overweight or obese and some adults have none.
When activated, brown fat keeps the body warm by burning calories. This has the potential to be helpful in fighting health issues such as diabetes and being overweight. More research is needed before brown fat can be used in this way.
When it comes to losing fat, claims of spot reduction – for instance losing fat just from the belly – are largely incorrect. Fat accumulates gradually throughout the body and it is reduced in much the same way. Rather than disappearing from a particular spot, it comes off layer by layer and fat loss tends to happen first from the most recent place it appeared.
There are four keys to successful fat loss plan. The first is exercise. Get 30 minutes of moderate exercise at least five days a week. The second is diet. Eat your veggies, lean meat and fiber. Drink plenty of water to stay hydrated. Third, make sleep a priority. Most people need at least six to seven hours each night. Fourth, learn to handle your stress. You may not be able to eliminate stress in your life, but how you deal with it matters.
White fat, brown fat, visceral, subcutaneous – not all fat is created equal. And, while a certain amount of fat is essential for healthy body function, too much or too little can lead to problems and chronic health concerns. If you are concerned that you might be carrying around excess fat, talk to your doctor about a weight loss and exercise plan that will work for you.
Dr. Palmquist is a board certified family practice physician at Raiter Clinic in Cloquet.