Purely anecdotal and unscientific, but a few years ago I watched a documentary in which a TV team followed identical twins. One of them only ate pasta-based meals for a month, the other only ate potato-based meals (if I remember correctly, they made sure that both meals where basically the same, modulo potato/pasta). They checked blood results, BMI, etc. before and after the diet. The potato-eating twin gained a few kilos and had generally worse blood results than the pasta-eating twin, who kept her weight. Interestingly, the potato-eating twin hated potatoes after 4 weeks of eating them and had to force herself to touch them at the end, while the pasta-eating twin still liked pasta.