Well there is a lot of logical explanations for that fact, the most simple, is that if your body has increased body fat that will contribute mainly to sweating that´s the most easy explanation.
But there are other things that may cause sweating and that is due to our genetics and psychology, sometimes sweating is something that your body produces without any metaphysic reason and it doesn't´t have to do with nothing in specific, but it can happen other times due to how we deal with life and how we are as persons if you are more apprehensive, nervous and uncomfortable your brain produces more sweating.