When you’re hungry and in a rush, a bagel, protein bar or handful of cereal might be convenient, but it's a short-term fix. “If you eat these foods when you are hungry, you may have a burst of energy at first, but after the sugar high, your blood sugar will plummet and send you looking for another snack.” says Bridget Swinney, a Texas-based registered dietitian and the author of Eating Expectantly: The Practical and Tasty Guide to Prenatal Nutrition. From pasta and microwave meals, to chips and juice, find out which foods are the worst for appetite control.