Just put them on a 2000 calory deficit diet during basic training, and double its duration.
That'll get rid of 80 pounds of excess fat, plus they won't have the strength to masturbate.
Sure, half of them will become casualties before they see action, but they can still pilot drones, do the funny or make coffee, while you can feed the other half into the front line grinder.
I'm not sure what you mean by that. If you're confused about the calories, 1 kcal (which is what people usually refer to when talking about food calories) is 1000 calories. A normal diet is a couple thousand kcal a day.