So if im 6'3 217lbs what calorie intake should I be under to lose 20lbs in a 4 wk span. Buddy of mine who fought in the last UFC went to a 1000 cal a day for two weeks due to be told late that he was fighting. He pulled it off but 1000 cals is very low. I know i can do it but what are health risks and if I can spread out to 4 wks i would rather do that. any suggestions? obviously after the 4 wks I would go back to my normal 4500 a day due to wanting to cut the fat. By mid summer I would go to lean bulk routine.