BTW, could you refer to some of these animal studies that show that reducing calories does not impact the weight? I hope the animals in question are not for example ants but more like primates or something resembling humans.

Got it. I've heard that theory before but never have I seen any substantial evidence. I accept that the food I eat might have some effect on my "hunger" and "energy level". Which in turn could make me eat more or exercise less. That doesn't really have anything to do with calories per se. Many other causes have the same effect, e.g. psychological or hormonal situations. However, the real argument seems to be that what one eats impacts one's "fat storage or metabolic rates". That's hard to believe. It would be interesting to see some hard evidence to support that claim. The present study tries to give some results, but I think the sample rate is insufficient. I've seen much evidence to the contrary.