Can I still lose weight if I drink diet coke every day?

Yes. Diet drinks generally have no calories, so drinking them will not increase the number of calories you take in. Make sure you're eating a balanced diet with plenty of fruits, vegetables, whole grains, and protein. For more info on weight loss go to http://www.Choosemyplate.Gov/ or http://www.Hsph.Harvard.Edu/nutritionsource/index.Html.