Thrifty gene 1-1

natural selection in humans evolved an efficient food storage system with optimum utilisation. Ancient humans went through cycles of feast and famine so their bodies were suited to fuel storage and optimum utilisation. But 800 with agricultural transition and food security with limited physical activity people perceptible to obesity and diabetes.

Minster et al 2016 found evidence for thrifty gene among Samoans. That provided security during famine by promoting obesity. 

Criticism. 

But studies show that it is in fact influenced by diet and exercise.