Food before doing Ashtanga Asanas

Many practitioners do not eat or simply just have a drink of coffee or hot chocolate before doing Asanas in the morning, so that they can do uddiyana bandha. However, I beg to differ and believe this is not the optimum method.
In Ashtanga, Asanas are meant to be comfortable in doing them. However, in doing Asanas, we strive to improve our body, either the body posture or internal organs through twisting, inversions, etc. The comfortable Asanas are probably for very accomplished Astanga Asanas practitioners; which begs the question: do Asanas benefit these very accomplished practitioners?
Therefore, for the average Ashtanga Asanas practitioners (who are still struggling with the primary, intermediate or the fourth, fifth or sixth series), what should we eat before doing Ashtanga Asanas?
During the process of struggling during Asanas, calories are burnt, water and electrolytes are lost, and muscle tissues are being torn and rebuilt. One of the electrolytes, Calcium which is not easily absorbed by the body, is needed to prevent muscle cramps.
Some of them practiced Armoli, which can provide some water and electrolytes, but it is not sufficient. The practitioners that do not consume food before doing Asanas try to compensate by eating after the practice; this is not optimum as food takes time to digest. Others get round this problem by drinking isotonic drinks and protein powder, but are there any undesirable side effects to these products?
For me, I take a light breakfast about 90 minutes before starting warm up for the Asanas. My breakfast consists of a cup of Milo as quick energy to kick start the body system, two half boiled eggs (for protein), a slice of cheese for Calcium and protein and a slice of wholegrain bread for vitamins and calories needed.
So, do you just take a cup of beverage and do the Asanas, do it on an empty stomach, or eat on that day’s wimps?