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50 pounds is 22,5 kg / 1kg bodyfat has about 7000 calories so that’s a 157.500 total calories to lose. Let’s say you burn total 3000 calories per day with existing and sport and eat 500 calories, you have a negative balance of 2500 calories per day. 157.500 / 2500 = 63 days
So in theory it can work, but the body is not a machine, it will adapt to your intake, tough to find a workaround, but no matter what, if you do that you will lose bodyfat for sure.
Maybe add a high calorie day per week to try to keep the body from adapting to the low calorie intake.