I really like the diet in Strong Women Stay Slim. I'd love to have an exchange for cake. I work at a place that frequently celebrates birthdays and has farewell parties - all seem to include cake.

Page 192 of Strong Women Stay Slim suggests an exchange of 1 Grain plus 4 Extras for a slice of chocolate layer cake. That's a useful average number. However, as you might guess, there's a lot of variation in cake equivalents, depending on both the type of cake and the portion size. A sliver of unfrosted angel food cake - which is a light, fat-free cake - might be the equivalent of 1 Grain plus 1 Extra. But the numbers could jump to 2 Grains and 5 or more Extras for a thick wedge of a dense fudge cake made with butter and whole eggs, which is filled and frosted with chocolate butter cream. Make your best guess and don't worry about getting the exchanges exactly right - sometimes you'll be a little too high and sometimes a little too low. So long as you don't consistently underestimate what you're consuming, it doesn't really matter. If you're maintaining a healthy weight, or losing half a pound to two pounds a week if you want to lose weight, then you know your estimates are on target.

A few suggestions about cake:

• Keep portions small - the first taste is usually the best anyway.
• Eat slowly; put your fork down between bites.
• Go light on frosting, which is usually the richest part of a cake (and often not the most delicious) - for instance, take an inner piece of a flat cake or the tip of a wedge of layer cake, to avoid the frosting on the side.
• Add fresh fruit to your plate if possible. If you're the hostess, garnish the cake with fruit rather than frosting.
• Enjoy! Festive food is one of the pleasures of life, something to savor in moderation.