You are right. There have been many recent studies on the effect of dairy products on fat loss. In fact, the American Dietetic Association (ADA) is now recommending 24 ouncesor three servingsof dairy per day.
Although these studies suggest that it may be the calcium that is causing the weight loss, studies using calcium supplements instead of dairy products have not produced the same results. This has led many to believe that calcium in combination with other nutrients in dairy products cause the weight loss. However, more research is continually being done in this area. Most studies to this point have been funded by the dairy council and very few studies (none conclusive) have looked at weight loss and soy milk.
If you look at calcium alone, soy milk has about one quarter the calcium of dairy milk (1 cup of soy milk has 80mg, 1 cup of skim milk has 316mg). Therefore, to get the same amount of calcium in soy milk as 24 oz. of dairy milk, you would have to drink about 95 oz,ounces or 12 cups. Many brands, however, are now fortifying their soy milk with calcium and have approximately the same amount of calcium as dairy milk. These are the brands to choose, but unfortunately, the fortified calcium is not absorbed as well as the naturally occurring calcium in dairy products.
Soy milk is an excellent alternative for those who are lactose intolerant because it is a good source of high-quality protein, B-vitamins, iron, and calcium. However, the jury is still out on its effect on weight loss. If you would like to try to incorporate some dairy into your diet, many people that are lactose intolerant can handle yogurt because of the probiotics. If you try this, be sure to try a brand with "live and active cultures."
Aside from the weight loss issue, consuming enough calcium is very important, especially for women, for total body health. Your body needs calcium to ensure proper muscle and nerve function, to help clot blood, for growth and reproduction of cells, and, of course, for bone health and the prevention of osteoporosis. Osteoporosis is much more common in women than in men. This is because women have less bone mass than men, tend to live longer and generally take in less calcium.
The best sources of calcium are dairy products such as milk, yogurt, and cheese. Dairy products also contain phosphorus and magnesium, and some are fortified with vitamin Dall of which aid in the absorption of calcium. Other good sources of calcium include green leafy vegetables, salmon, shellfish, almonds, brazil nuts, and dried beans. Some common food products, such as bread and orange juice, are often enriched with calcium.
Supplementing your diet with some of the aforementioned food products, on top of drinking soy milk, will provide the majority of the benefits you would see from cow's milk.