Many of us view fat (also known as adipose tissue) as the body’s storage system for extra calories, like a pantry we can tap into during times of need or when we’re out on a long hike without snacks. While this is partially true, there are different types of body fat that play diverse roles.
If you’re focused on reducing body fat or maintaining a low percentage, you may unintentionally disrupt some of your body’s essential functions, such as blood circulation and cell repair and growth.
“Fat is a crucial component of a living, functioning individual,” explains Dr. Gillian Goddard, M.D., a general endocrinologist and adjunct assistant professor of medicine at NYU Langone Hospital. “Fat is not just a passive storage for excess energy or calories.”
Discover the significance of body fat and the distinctions between its various types.
1. White Fat
“White fat cells are large structures with a central lipid droplet surrounded by cellular components,” Goddard clarifies. White fat mainly serves as storage for excess energy.
There are two familiar forms of white fat: subcutaneous and visceral.
Subcutaneous fat
For most individuals, subcutaneous fat consists mainly of white fat cells and is the layer of adipose tissue just beneath the skin. It is commonly found in the arms, legs, and abdomen, storing excess calories and providing insulation to maintain body temperature.
“When you maintain a healthy weight, subcutaneous fat typically does not pose metabolic risks or contribute to insulin resistance,” notes Goddard. Embracing body positivity, it is possible to have curves and still be healthy.
However, if you’ve ever hesitated to share a photo due to dimpled skin on your legs (cellulite), subcutaneous fat is the culprit. Cellulite occurs when fat protrudes through the connective tissue under the skin.
Visceral fat
If there is one type of fat to label as “bad fat,” visceral fat, or deep fat, fits the bill. Comprised entirely of white fat cells, visceral fat forms in the abdomen and around organs. While some visceral fat is normal, excessive amounts can elevate the risk of diabetes and other serious conditions, like liver dysfunction.
“Visceral fat significantly contributes to health issues associated with excess body fat,” states Goddard.
An obvious sign of excess visceral fat is a firm “beer belly,” but it’s also important to monitor waist size. Women with a waist circumference over 35 inches or men over 40 inches likely have enough visceral fat to impact their health negatively.
2. Brown Fat
One of the significant shifts in understanding body fat types in recent years has been the recognition of a new category: brown fat.
Unlike white fat, brown fat cells contain a small lipid droplet and dense cellular components, giving them a brown appearance. These components include mitochondria, where fats and glucose are burned to produce heat.
Contrary to the notion of idle fat cells, brown fat is metabolically active and is currently being investigated for its potential in treating obesity.
In adults, brown fat is located in areas like the neck, collarbone, and spine. The amount varies among individuals. While brown fat burns calories, accumulating it is challenging and doesn’t involve indulging in ice cream. “Studies suggest that exposure to cold temperatures can stimulate its development,” notes Goddard. However, it’s not as simple as going for a cold morning run in shorts or standing in a freezer aisle deciding on ice cream flavors. Some research indicates that prolonged exposure to temperatures at 60 degrees or lower can trigger brown fat production. Beige fat falls into a gray area within the spectrum of adipose tissue. Studies suggest that mice can convert white fat cells into beige fat, a process known as “browning,” which may also occur in humans. Typically found in small deposits near the collarbone and spine, beige fat, like brown fat, burns calories and generates heat. However, beige fat is a recent discovery, and much about it remains unknown, according to Goddard.
3. Beige Fat
