By Barbara Florio GrahamFrom McCall's, June, 1983I read every diet I can get my hands on. I even follow their suggestions. But eventually, inevitably, I always get fat again. Now, at last, I've found The Answer. After living for almost 14 years with a man who never gains an ounce no matter what I serve him, I've found out what it is that keeps him thin: He thinks differently. The real difference between fat and thin people is that thin people:avoid eating popcorn in the movies because it gets their hands greasy;split a large combination pizza with three friends;think Oreo cookies are for kids;nibble cashews one at a time;think that doughnuts are indigestible;read books they have to hold with both hands;become so absorbed in a weekend project they forget to have lunch;fill the candy dish on their desks with paper clips;counteract the midafternoon slump with a nap instead of a cinnamon Danish;exchange the deep-fryer they received for Christmas for a clock-radio;lose their appetites when they're depressed;think chocolate Easter bunnies are for kids;save leftovers that are too skimpy to use for another meal in order to make interesting soups;throw out stale potato chips;will eat only Swiss or Dutch chocolate, which cannot be found except in a special store;think it's too much trouble to stop at a special store just to buy chocolate;don't celebrate with a hot-fudge sundae every time they lose a pound;warm up after skiing with black coffee instead of hot chocolate and whipped cream;try all the salads at the buffet, leaving room for only one dessert;find iced tea more refreshing than an ice-cream soda;get into such interesting conversations at cocktail parties that they never quite work their way over to the hors-d'oeuvre table;have no compulsion to keep the candy dish symmetrical by reducing the jelly beans to an equal number of each color;think that topping brownies with ice cream makes too rich a dessert;bring four cookies into the TV room instead of a box;think banana splits are for kids.