Researchers have identified new genes linked to an increased risk for obesity.
Two studies published in the journal nature genetics identify gene variants that increase a person's appetite, and therefore their waistline.
Each variant had a minor contribution to weight gain, but when someone had multiple gene mutations it added up to 10 extra pounds.
Experts say this research shows appetite regulation plays an important role in obesity, in addition to how the body uses and stores fat.
Researchers say there are likely several more genes that increase the risk for obesity, and more studies are needed.