Many people view fat, also known as adipose tissue, as akin to a kitchen cabinet in the body — a system for storing surplus calories that we can utilize during times of need, such as on a long hike without snacks. While this perspective holds some truth, it is essential to recognize that different types of body fat fulfill distinct roles.
If your primary objective is to shed body fat or to maintain a low body fat percentage, you may inadvertently interfere with several vital bodily functions, including blood circulation and the repair and generation of new cells.
“Fat constitutes one of the fundamental components of a living, functioning individual,” states Dr. Gillian Goddard, M.D., a general endocrinologist and adjunct assistant professor of medicine at NYU Langone Hospital. “Fat is certainly not just a passive storage for surplus energy or calories.”
Discover the significance of body fat and the differences among its various types.
1. White Fat
“White fat cells resemble large blobs with a substantial lipid (fat) droplet at the center and a thin rim of cellular machinery,” explains Goddard. White fat primarily serves as a reservoir for excess energy.
You are likely familiar with two types of white fat: subcutaneous and visceral.
Subcutaneous Fat
For the majority of individuals, subcutaneous fat primarily consists of white fat cells and is the layer of adipose tissue located just beneath the skin. This type of fat is predominantly found in the arms, legs, and abdomen, where it stores surplus calories and provides insulation, acting as a natural protective layer.
“When you sustain a healthy body weight, subcutaneous fat generally does not lead to metabolic issues or insulin resistance,” notes Goddard. In the spirit of the body positivity movement, it is entirely feasible to possess curves and still be fit.
However, if you have ever hesitated to share a photo of yourself due to the appearance of dimpled skin on your legs (commonly referred to as cellulite), subcutaneous fat is the culprit. Cellulite develops when fat protrudes through the connective tissue beneath the skin.
Visceral Fat
If there were to be a type of fat labeled as “bad fat,” it would likely be visceral fat, also known as deep fat. This type consists solely of white fat cells and accumulates in the abdominal region and around internal organs. While having some visceral fat is normal, excessive amounts can heighten your risk of serious health issues, including diabetes and liver dysfunction.
“Visceral fat is one of the most significant contributors to health complications associated with excess body fat,” states Goddard.
A prominent sign of excessive visceral fat is the presence of a firm “beer belly,” but it’s also important to monitor your waist size. Women with a waist circumference exceeding 35 inches and men with a waist circumference surpassing 40 inches likely have enough visceral fat to adversely affect their health.
2. Brown Fat
One of the most significant advancements in understanding the types of body fat in recent years — and perhaps the most perplexing — has been the recognition of a new category: brown fat.
In contrast to white fat, brown fat cells possess smaller lipid droplets and denser cellular components, which gives them their brown appearance. These components include mitochondria, where fatty acids and glucose (sugar) are metabolized, generating heat.
Contrary to traditional beliefs about inactive fat cells, this type of fat is metabolically active and is currently being researched for its potential applications in obesity treatment.
“Previously, it was thought that only infants had brown fat,” Goddard explains. “However, adults also possess brown fat.” This type of fat assists in regulating body temperature, which is why infants have a higher concentration of it. As individuals develop muscle to retain warmth, they lose most of this “baby fat.”
In adults, brown fat is located in areas where the neck meets the torso, above the collarbone, and along the spine. The quantity varies from person to person.
Although this fat type helps burn calories, gaining it is not straightforward. Unfortunately, it doesn’t involve indulging in ice cream.
“Researchers have discovered that exposing oneself to cold temperatures can promote its development,” states Goddard. However, it’s not merely a matter of going for a jog in chilly weather or standing in the frozen food aisle pondering ice cream choices. Some studies indicate that prolonged exposure to temperatures of 60 degrees Fahrenheit or lower can stimulate its production.
3. Beige Fat
Beige fat occupies a somewhat ambiguous position in the spectrum of adipose tissue. Research indicates that mice can convert white fat cells into beige fat, and this “browning” of white fat cells may also occur in humans.
Typically found in small deposits near the collarbone and spine, beige fat shares similarities with brown fat in that it helps burn calories and generates heat. However, like brown fat, beige fat is a relatively new discovery, and much about it remains to be understood, according to Goddard.
