Fat comes in different colors, and the color can give clues about whether it is healthy or unhealthy. The main types of fat in our bodies are white fat and brown fat. White fat stores energy while brown fat burns energy and generates heat. The color of fat depends on the amount of blood vessels and mitochondria it contains.
What Gives Fat Its Color?
The main factor that affects fat color is the amount of blood vessels and mitochondria present:
- White fat has fewer blood vessels and mitochondria, giving it a white color.
- Brown fat is packed with blood vessels and mitochondria, giving it a brownish/red color.
Mitochondria are the parts of cells that burn nutrients to produce energy and heat. More mitochondria means more fat burning potential.
White Fat
White fat, also called subcutaneous fat, is the most common type in the body. It exists right under the skin (subcutaneous layer) and surrounds organs and muscles. White fat contains a single large fat droplet that pushes the nucleus to the edge of the cell. It has fewer blood vessels and mitochondria than brown fat.
The main roles of white fat are to:
- Store excess energy as triglycerides
- Insulate the body and protect organs
- Secrete hormones like leptin and adiponectin
Having some white fat is normal and healthy. But having too much, especially around the stomach, can increase disease risk.
Brown Fat
Brown fat exists mainly in small deposits around the shoulders, neck and along the spine in humans. It is densely packed with blood vessels and mitochondria. This gives it a brownish/red hue. Rather than one large fat droplet, brown fat cells contain many tiny droplets around a central nucleus.
The main role of brown fat is to burn calories to generate heat through a process called thermogenesis. It helps protect against hypothermia in infants. Some evidence also suggests it may help regulate body weight by increasing calorie expenditure.
Which Color Fat is Healthier?
Brown fat is considered the healthier fat for a few key reasons:
- Brown fat burns calories and generates heat via thermogenesis, while white fat solely stores calories.
- Higher brown fat levels are linked to lower body mass index (BMI) and body fat percentage in adults.
- People with obesity have been shown to have less active brown fat.
So while white fat serves important functions, brown fat appears to be more metabolically active and may provide health benefits by burning extra calories.
Increasing Brown Fat
Research is ongoing into ways to increase brown fat activity and levels. Some strategies include:
- Exposing yourself to colder temperatures.
- Exercise training, especially high-intensity interval training.
- Certain foods like capsaicin, green tea and retinoic acid may also help.
What About Beige Fat?
There is a third type of fat called beige or brite fat. This refers to pockets of brown-like fat that can develop within white fat tissue. Beige fat can start to take on properties of brown fat like burning calories and generating heat in response to certain stimuli like cold exposure.
Some research shows adult humans may have more beige fat than brown fat. Exercise and cold exposure may help convert more white fat to beige fat.
Conclusion
Brown and beige fat contain more blood vessels and mitochondria than white fat, giving them a browner color. They are more metabolically active and may provide health benefits through thermogenesis and calorie burning. Increasing your amount of brown or beige fat may support weight management. Exposure to cold temperatures and exercise are two ways to potentially do this.