...and eat healthy. Why? I am a 20 y/o male. From January-May of this past year, I gained about 15 pounds, but I figured this was because I was at school, and I was not excersing regulary along with eating badly. So when I got home from school in late May, I began excersing regulary, running at least 1.5 miles four or more days a week, along with lifting weights. I also have been watching what I eat, cutting down on fatty foods. However, I just weighed myself the other day, and ive GAINED 10 pounds since I came home from school, despite all the excersise. Why is this?