This is thriftygene.net
This is an explanation of why the Atkins diet leads to large weight loss for people with the “normal” gene and not so much for people with the “hunter” gene.
The body produces insulin to process protein.
(Unfortunately?) this also leads to the body turning sugar into fat.
This possibly leads to the body producing hormones to create insulin resistance to prevent very low blood sugar. In any case blood sugar becomes lower than the body is comfortable with. The liver changes fat into sugar.
The reaction sugar into fat and then fat into sugar is very energy intensive. You use a lot of energy and you lose weight.
People with the “hunter” gene are usually insulin resistant they do not turn sugar into fat.
It is true that protein is not stored as fat and only a limited quantity of protein can be used at one time by the body. So you can eat as much protein, but not fat, as you like and not gain weight.