Yes, certainly. But those do not account for a significant change in the baseline consumption of calories. The baseline need remains significant, despite the body's attempt to cut corners. It's not a question of whether the body tries, it's a question of how effective it is -- and it's not very.

Those effects I believe are also correlated with extremely low bodyfat moreso than a calorie deficit diet. In most cases a healthy person's body will simply consume fat to account for a deficit in the diet.

We unfortunately have a lot of data about starvation. The effects on the body are very clear. Body fat will go first. Most americans are in absolutely no danger.