Right now, cooking (which is a part of crafting) is considered to be “Moderate Exercise”. This means the player is spending as many calories boiling water as he does cutting down trees. In my opinion, it should be “No Exercise” or at most “Light Exercise”. (This is a one-line change in json).
I ran into this while trying to figure out why my character was losing weight. It turns out the cause of the weight loss was cooking pemmican.
It looked like a good idea since I had a lot of lard laying around, and pemmican was a way of making use of the calories in the lard. I will spare you the calculations, but with the current mechanics, I was close to burning more calories cooking the pemmican than I was gaining from incorporating the lard.
I needed to open the debug menu to figure it out. This must be very confusing for new players; it certainly was for me.