Marcia,
Kim wrote some good stuff on weight loss in teh backpacking thread on general discussions, you might want to read that. Red bull has about 27 G of carbohydrate, mostly sugar and that seems like alot, but there are only 110 cal in each one. It shouldn't be that much of a problem. It has about the same amount of caffeine as a cup of coffee.
I don't know what your diet is like. Do you know what your body composition is, it maybe that 20 lbs is too much. I am your age and thought my BF was too high, it measured 34% on my scale. I had it measured through calipers and it was 21%.
Are you taking any supplements? Do you eat processed food, sliced meats, frozen dinners, canned soups - they contain alot of salt.
If you want turn your sharing on.
Terry