I usually get a bag of about ten grapefruits from Costco. As soon as I get home I cut them in half and slice all of the grapefruit out into a Tupperware container. This usually takes about an hour but lasts for two weeks. I really got into grapefruit whenever I would do a pre-race diet. The most effective diet for me was the Mayo clinic diet which always allowed me to lose twenty pounds in two weeks. Breakfast was always the same: a half grapefruit, slice of toast and a cup of coffee or tea. Breakfast was one of my favorite meals because of the grapefruit. The rest of the Mayo Clinic diet was good but really cut back on carbohydrates which made the grapefruit a very special treat. I had read that Grapefruit and Pineapple are great fruits for speeding up your metabolism and eating up fat from your diet as well.