Not a gimmick...........a friend of mine.
Just eat thin air as opposed to thick air and the 16 pound loss can be achieved! 
Ah, ok. I still say it's a goofy exercise in dehydration tho with nothing but downsides and possible health consequences.
What's 16 lbs, near 15% of your body weight? Any coach who insists on this is no coach at all. You might consider telling him to go suck an egg.