Unlike normal white fat that stores surplus energy, brown fat generates heat in response to cold or excess caloric intake. While some mammals such as rodents maintain this 'good' fat throughout life, humans are similar to lambs: brown fat is present in the newborn to act as an internal central heating system maintaining body temperature and preventing hypothermia, but rapidly disappears as brown fat is irreversibly replaced by normal white fat.
Now, researchers based at Imperial's Wye campus in Kent are determining the molecular switch in lambs that transforms brown fat into normal white fat, and investigations are underway to determine whether this conversion could be reversed and used as a new fat busting technique.
Professor Michael Lomax, head of Imperial's Animal Science Research section at Wye and leader of the project says:
"Obesity is fast becoming one of the biggest problems for the Western world. In the UK statistics suggest 20 per cent of us are overweight and in the USA the situation is even worse with more than 60 per cent of the population either overweight or clinically obese.
"While researchers continue to investigate how to increase the body's natural appetite suppressants most of us at some point will have resorted to some kind of diet to move those couple of extra stubborn pounds. But by reactivating natural brown fat we could lose weight without even trying.
"Each year between two to three million newborn lambs die of hypothermia at cost of up to 100 million to the industry. Farmers have even tried to put quilted jackets on vulnerable lambs to try and save them from hypothermia during cold, wet snaps but often it's difficult to reach lambs in time especially in remote areas. The ability
Contact: Tom Miller
Imperial College London