"The more we learn about genes and how people react differently to different foods the more intrigued I am by the idea of an "optimal" diet only being achieved

"The more we learn about genes and how people react differently to different foods the more intrigued I am by the idea of an "optimal" diet only being achieved on a person-by-person level." For me, it's implicit that optimizing diet can only be done on an individual basis. It's pretty obvious, at least to me, that taking maternal twins and having one be active while the other remains inactive for most of their lives leads to the need for different diets between the two.