Calcium may be helpful. It's marketed toward women, but the truth is that most people have calcium deficiencies. I would see how much calcium is in your men's vitamins; usually, they don't contain a lot of calcium compared to women's vitamins. People who have enough calcium essentially "poop out" the fat that they consume. You can tell if you're getting enough calcium by whether or not your stool floats in the toilet. If it floats, it means that it is composed of fat. Fiber is also important and helpful in weight loss (or maintenance).

I would be careful about drinks and powerbar-type things, because although they have protein, they are also loaded with sugar or other sweeteners (for taste) and consequently, extra calories. If you have a store like a GNC nearby (vitamin store), try asking someone who works there.