From the time that you eat, there should be at least three hours gap prior to practicing yoga, whether you exercise in the morning or evening, as this will enable you to perform Yoga Asanas appropriately. Otherwise you might have stomach pains and risk the possibility of hurting your digestive areas when doing stomach, back or any exercises where you're required to do twist and turns, be it standing or sitting down.
Almost all Asanas require breathing and Pranayama requires deep breathing. So, exercising on a full stomach will affect your ability to breathe deeply as your stomach is already bloated with food. Plus, eating before you exercise will mean that your body will spend more time to digest and as a result, will burn less fat potential. However, eating lightly such as fruits will ensure that you obtain maximum benefit of physical and breathing Asanas performed, as your body will spend less time processing food.
Benefits of Exercising in the Evening