You can eat before a workout, but the key is timing. If you eat a large meal right before exercising, your body slows digestion as energy is sent to your muscles for your workout. Sometimes the result is cramping and an upset stomach. An easy workout like a moderate walk will not have the same effect, so the easier the workout, the safer it is to eat a meal beforehand.
Waiting at least an hour after eating is best. If you are going to eat as little as an hour before you workout, make sure that it is a light snack such as a banana or an apple. A snack that has carbohydrates will give you an energy boost. If you are going to be doing a very intense workout like running a long distance or a high intensity weight workout, you should have a meal about two hours before you workout.
Allow Time to Digest
It generally takes 1-4 hours to digest a meal and everyone is different, so you should experiment to find out how you feel while working out. Glucose is the best source of energy for muscles as you are working out, you should consume a carbohydrate-based meal about two hours before your workout. Choose whole grain bread, pasta or cereal. If you are hungry right before you exercise, eat something light to starve off hunger pains while you are eating. The best way to avoid that though is to eat regular meals throughout the day and plan your larger meal a couple of hours before your workout.
Eating before a workout is important, but make sure that you give your body time to digest what you have eaten. The closer you get to your workout time, the lighter your meal or snack should be. Your body and muscles will find it easier to perform.