If adipose tissue had a hierarchy, then brown fat would definitely be on top!
Brown adipose tissue (BAT), also known as brown fat, is found in much smaller amounts compared to our standard white fat, located deep within the torso and neck. As we know, the role of white fat is to store excess energy which can then be used at a later point. Contrastingly, the job of brown fat is to produce heat when our body is cold, therefore expending energy. Surely then, if we have more brown fat, we can lose more weight?
Unfortunately, it is not that simple. Brown fat is only found in small quantities and burns very little energy unless it is ‘activated’. For example, cold showers have been promoted as a means to activate BAT, although they are neither cold or long enough to have a meaningful effect. Even certain foods such as green tea and chillies have been popularised by their proposed effect on brown fat. However, we have to remember that BAT is around as a survival mechanism, and therefore requires cold exposure of several hours per day! Even if you are determined enough to shiver for a good chunk of your day, the upregulation in appetite from cold exposure is likely to negate the positive effects from brown fat.
Our consensus – brown fat is certainly an interesting and novel part of our physiology, although we would recommend sticking to the basics of an energy deficit if your goal is weight loss.