yep I do it quite often as I don't have the three slim fast snacks a day, I also have low calorie soup for lunch instead of a shake it shouldn't hurt as long as you don't go over.. I think you have to have at least 1200 otherwise your body doesn't go into keratosis but it shouldn't be damaging if you don't eat your full quota of calories either as several days this week I haven't eaten the 1280 my fitness pal has put me on x