The best way to support your body before yoga is to not eat. This approach is very much unlike carb and protein fueling before high intensity workouts, which aim to improve athletic performance. The goal of asana is not physical achievement, but creating a healthy body. To eat and then practice asana would go against this objective by impairing digestion. Therefore, yogis advise against it.
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Almost all asanas in some way twist, stretch, invert, compress or expand the abdominal organs. The aim is to stimulate and balance the digestive process. But to do so on a full stomach would disrupt the natural downward flow of digestive action. The only asana that’s recommended after eating is vajrasana, in which the GI tract is vertically stacked as intended to ensure good digestion.
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Interestingly, the ideal time for yoga is in the early morning hours of Brahma muhurta: about 90 minutes before sunrise. It’s taught that the atmosphere is the most calm and peaceful at this time, as most of nature’s creatures are still sleeping. But there’s another reason why this time is recommended. At this hour, yogis will undoubtedly be able to practice asana before their breakfast, which is better for the body.
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When early morning yoga is not possible, it’s best to allow three hours in between a full meal and an asana practice. This gives the body plenty of time to digest. If this is not possible, make it two hours at least. Anything less and the meal should be very light. Fresh fruit, dried fruit, steamed vegetables or a little vegetable soup are all okay.
Even water has to be digested, so large quantities should not be consumed just before asana. Instead, sip warm water to quench thirst. Then during asana practice, avoid drinking water as much as possible. Never drink ice or cold water during a yoga session (and best to avoid these in general). Drinking fluids during asana can create digestive issues.
All in all, yogis should aim to eat meals at regular times and schedule their yoga practice accordingly. Early morning is best, with sometime around sunset being the runner up. (By this time lunch will mostly be digested.) Pre-workout meals simply don’t apply when it comes to yoga; asana should never be so intense that carb loading is needed.
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