Snacks help suppress your appetite to avoid overeating during your meals. They also give you a boost of energy if it has been hours between meals and the glucose in your blood is dropping.  Snacks offer more nutrition if you have a poor appetite due to illness, especially if you choose fresh fruit and nuts. 

You may experience unwanted weight gain if you are frequently snacking.  This can be avoided by reading the labels on your packaging and determining how many calories are in one serving. If you are snacking on foods high in sugar, fat, or salt, this may lead to unwanted weight gain as well or high blood pressure.  Aim for snacks that do not have a lot of sugar, fat or salt. You should only eat enough to satisfy.  You don't want a snack to interfere with your appetite for a meal or add too many calories to your day.  Keep that in mind when reaching for packaged snacks.  Read the labels to determine the serving size. A good idea is to aim for about 150-250 calories per snack.  This is about the same as an apple with a tablespoon of peanut butter, or a string cheese with 6 whole grain crackers.