Lo-Fat vs. Lo-Carb

I've been to Weight Watchers meetings and listened to the propaganda about points and low-fat.... I've read Dr. Atkins's treatise on the benefits of Low-Carb. Dr. Phil is out there telling us all to "just use some common sense." At work, I've interviewed nutrition experts - each defending his or her camp. Is the USDA food pyramid really making us all fat?

What do you think?

Should humans be watching fat intake? Carb intake? Is the weight problem really a matter of physical fitness and not food? What have you tried? What worked? What abysmally failed?

A few years ago when I joined Weight Watchers, I actually GAINED 10 lbs. Although Atkins works for me, it doesn't seem to be the natural way to eat for life. And no matter how I eat, the key to maintaining a normal,healthy weight has been exercise.