Depends what you're trying to lose. Just 5 lbs? Incl water weight? or just 5 lbs of FAT?
5 lbs of water weight is easy to lose... take a diuretic, do some cardio to sweat and watch your sodium intake. However that's not a healthy solution as you're mostly just dehydrating yourself.
To lose 5 lbs of fat, it will take some major work. 1 lb of fat = 3,500 calories. So to gain a lb of fat you need to take in 3,500 more calories than your body uses and to lose 1lb of fat you need to burn off the equivalent of 3,500 more calories than you are taking in. 5lbs in a week might be pushing it too hard for some people resulting in muscle loss, immune system greatly weakened, and many other issues.
