Figure 3.

Duality of lipid metabolism in the infant subcutaneous adipose tissue. The adipose tissue in the infant has mitochondria-rich “beige” or “brown” adipocytes and fat storing “white” adipocytes. The beige or brown adipocytes actively break down neutral lipids, and oxidize fatty acids via mitochondrial β oxidation to produce ATP, or use fatty acids to generate heat from uncoupled terminal electron transport of the mitochondria. Moreover, they release free fatty acids (FFA) into the blood circulation, which are used by energy-demanding organs, such as the heart, the liver and the renal cortex to produce ATP. White adipocytes have lipogenic activity and build up lipid stores. Breast milk lipid signals sustain the differentiation of beige/brown adipocytes. When the amount of the beige/brown adipocytes decreases (for instance, due to insufficient breastfeeding or in response to obesogenic signals), childhood obesity develops.