Does diet have an effect on gains? If we get all our protein and nutritional requirements but we eat icecream and junk food at night will this effect gains?
What a bad diet like that will do is mess up your heart because it can start to clog your arteries restricting blood flow. And if blood is being restricted to your heart it is also being restricted to your cock. The best diet for your cock is a heart healthy diet.
The primary goal of PE should be to make your penis as healthy as possible in both form and function. If you do that, increased size will follow.
Getting fat makes your dick look smaller, and it also makes you unattractive to women.