no it wont work because cereal is a ton of carbohydrates and carbs make u fat. All u need to do is run keep exercising eat alot of fruits and veges and if that guy really lieks u then he wont care if u have a little chub n e ways ive lost 40 lbs in less than a month im sure u can lose 5 lbs in 3 weeks eating as much as u want and jsut exercising