Each month iVillage poses a different question to our Dream Team of experts. Here's what we asked this month: What's a better choice for weight loss, dairy or soy?

Lynn Grieger, RD, CDE
Like it or not, losing weight comes down to calories. Most soy milk is fortified with calcium and vitamin D to make it nutritionally comparable to cow's milk. Everybody knows that nonfat cow's milk has less fat ‑- and therefore fewer calories ‑- than 1 percent, 2 percent, or whole milk (which is 3.25 percent fat, in case you wondered). A cup of nonfat cow's milk has 83 calories, compared to 102 calories in 1 percent milk, 122 calories in 2 percent milk, and 146 calories in whole milk. Drink the recommended three cups per day, and you'll end up with 189 additional calories if you choose whole instead of nonfat milk. That might not seem like much, but it adds up over time. If you drink three cups of milk each day, switching from whole to nonfat milk could help you lose almost 20 pounds in a year!

Soy milk comes in a variety of flavors, some with added sugar. Plain soy milk has 100 calories per cup, comparable to 1 percent milk. You can also purchase light soy milk, with almost half the fat of regular soy milk, at 70 calories per cup.