Hello!
The best way I have found to lose weight is to count calories-eating about 1500 calories a day. Losing weight is a simple matter of burning more calories than you take in each day. The low fat eating can be combined with this very easily-I try to make lower fat choices not for the weight loss part of it, but for it being healthier for your heart, etc. Regular exercise is extremely important as well-because you can lose weight and be THIN at 120 pounds, and still have flappy arms and saddlebags and jiggly inner thighs. I have seen many thin women with saggy rear ends because they don't do anything.

If you want a nicely shaped body as well as cardiovascular and bone health-you must exercise. If you don't use it, you'll lose it. This is why you see 120 pound women looking at their thighs and saying they are fat. THEY ARE! Not in size, but in composition.
You also have to give up the thought of going on a "diet." A diet means that you will lose weight, go back to your regular habits, and then gain it back-and then in a few months, go on another diet.
You have to commit to changing your eating and exercising habits for LIFE-if you want to keep it off for life.
Aphil