The main reason why people lose weight when they stop drinking pop, or switch to diet is because of the way the body processes HFCS (High Fructose Corn Syrup. HFCS is not recognized by the body as a usable sugar and it is IMMEDIATELy processed by the liver and STORED as FAT. Check labels and steer clear of anything that has high fructose corn syrup. You are much better off brewing up a pitcher of iced tea and sweetening it with regular table sugar or honey.
My green tea iced tea recipe:
5 Lipton Green tea bags
Juice of 1 orange
Juice of 1 lemon
1/4 cup of sugar
1/4 cup of honey
Another drawback to drinking pop is the carbonation. The CO2 is absorbed into the blood and actually makes respiration harder. The lungs have to work harder to clear the extra CO2 from the blood.