The possibility of an allergic reaction to peanuts might be a good point. I have not experienced any other side affects (that I'm aware of) from eating peanuts, with the exception of some intestinal discomfort/gas that I get when I eat 1/2 - 1 lb at a time. I have always liked nuts and have never noticed any physical reactions to any types.
The amount of sweating also slowed somewhat after the first few days though the food intake did not change. I stopped eating both peanuts and popcorn for a couple of weeks and the profuse sweating seemed to stop at that time. I have again started eating popcorn regularly, but no peanuts for weeks now--no unusual sweating. I will make a point to buy more peanuts and add them to my diet again and see what the affect is.
For the record, the peanuts are much saltier than the popcorn I buy. Nothing else in my diet has changed, though I have reduced my already low salt intake by making further reductions of it in what I cook--trying to compensate for the popcorn.
Also, I live in Phoenix, which is an arid environment most of the time. When it is humid (happens during monsoons), I still sweat just as much in the heat, it just doesn't evaporate quickly and I do a lot of wiping to eliminate buildup.