Clearly that is not enough food.
The ashtanga vinyasa yoga practice is a reflexive one, meaning it reflects on, and in turn is reflected upon, other aspects of your life.
Some of the biggest gravitational bodies to exert larger tidal pulls are diet, sleep, relationships, work, and stress.
Are you getting your 9-to-11 hours of sleep a night? No?
If you are a bipedal primate belonging to the species Homo sapiens, you need your 9 hours every night. Especially if you're undertaking a physically demanding endeavor such as two hours of ashtanga vinyasa daily.
The question of what constitutes a supportive diet --- and in turn, the question of how our practice supports, effects and influences our diet --- is much trickier. As you're a bipedal primate of the species Homo sapiens, you are an omnivore, and can survive on wood chips or filtered cow's blood (i.e. milk).
Patanjali didn't concern himself so much with the specifics of what to eat, though his suggestions for the yamas and niyamas, one's personal and social ethical qualities, provide a framework in which to make one's dietary choices.
Pattabhi Jois wrote a bit about diet in Yoga Mala. The guy was nothing if not common-sense.
"If the mortal body is to be sustained, things like food are essential. After all, by sustaining the body, does one not attain divinity through following the righteous path? Thus the food we eat should be pure (sattvic), untainted (nirmala), and acquired by righteousness, and not be secured by cheating, deceit, persecution or other unjust means. Only taking as much food as we need to maintain our bodies, and not desiring things of enjoyment which are superfluous to the physical body, is aparigraha." (P.24)
Guruji also had some suggestions of what our food should — and should not — be comprised. I don't feel the need to talk about that, save to say that genetic, personal, and social context (your samskaras) should be taken into account.
In my experience with this particular system, many people tend to under-eat. That is, many people tend to not eat enough to support recovery and growth from the physical stress of ashtanga vinyasa practice, with its emphasis on 2-hours-plus practices of strength wedded to active flexibility.
I'm sorry I'm not sorry, but if you aren't sleeping right now, you need to be eating.