I've been sick too. Best advice for me is pushing fluids. Assuming you're not diabetic, Powerade and Gatorade are good for hydrating (especially if you've had vomiting, diarrhea, and/or fever). I've been trying to drink two 32 oz Powerades per day. I am also drinking Airborne three times a day. I fill up a 16 oz cup with water and drink about 10 oz plain, then I dissolve the tablet and drink the last 6 oz. Chicken soup doesn't have a lot of calories (a can of Progresso has two 100 calorie servings) and of course...drink the broth too!