Welcome to the world of the little golden pineapple."" No relative of the Scarsdale Diet, the Beverly Hills Diet consists of large quantities of fruit plus a few other foods, its own jargon (maxi carbs, Mono Meals, the Resnick Open), and motivational lessons that echo The Little Engine That Could. Every bite counts, whether on the initial five-week diet (intended to detoxify your system) or later when your stomach can accommodate the enzymes from other foods. ""The idea of eating a 'balanced' meal is as absurd as wearing two skirts and two pairs of shoes at the same time,"" Mazel asserts. Eating one food at a time, in large quantities, is much more effective. (""Five pounds of grapes on a grape day is not excessive."") On the first day, eat all the pineapple you want, then two bananas in the evening. On day eight, half a pound each of prunes and raisins. The next two days, only grapes. (""If you have loose bowel movements, hooray! . . . The more time you spend on the toilet, the better."") Salt and cheese are frowned on, and if you eat chicken, you must eat the skin too. Restaurant eating is easy: just bring your own watermelon or order four potatoes, served one at a time. Bananas.