Except it doesn't in the realm of weight gain/loss. People's metabolisms vary by a wide margin, we could both eat exactly the same and I could lose weight, while you gain.
Of course, top athletes can burn through 2-3 times what a desk-worker might burn through. And I think the small number I mentioned above also tells that you can slowly but steadily put on quite some weight, by eating every day just one slice of bread more than you need.
[1] https://examine.com/faq/does-metabolism-vary-between-two-peo...
I coach myself and other bodybuilders/figure athletes on the side, consider this anecdotal. Working with the extremes of muscle mass I've found that it can affect metabolism a great deal. Simply by the fact that you have so much more weight to carry around/maintain. For example, I maintain weight at 205lb @ 5'7" (relatively) lean at 3500 kcal, for a competition I have to be ~170lb, my maintenance intake at that weight is closer to 2000kcal. Note that exercise also increases closer to a competition, so that 2000kcal maintenance is with higher activity levels than offseason.
With this research, it's seems possible to make two persons to react the same to most food, by making their microbiotic flora the same.