What you eat has a huge impact on your yoga practice, more than anything else that you do off the mat (or cushion).
Most classical Hatha Yoga texts offer advice on diet, some of it isn't very practical.
Generally, however, a light vegetarian diet is the only one suitable for serious practitioners.
The Yoga Yajnavalkia lists Mitahara (moderation in diet) as one of the basic yogic disciplines (yamas),
and the Hatha Yoga Pradipika states that overeating "destroys yoga" (HYP 1,15).
The Buddha also recommended eating a moderate diet as this helps to abandon two of the five hindrances to practice: craving for sense pleasures and laziness
Indeed, overeating dulls the mind and weight down the body, ruining any chance of progress in yoga practice.
The advice generally given by classic texts it to fill half of the stomach with satvic (pure and light) food, drink pure water to fill half of the remaining volume, and leave the last quarter of the stomach empty. It is also interesting that both Yoga and Buddhism have as training rules for serious practitioners not to eat more than two meals a day (and in the case of Buddhist monks, only one meal a day).
Snacking between meals, which mixes undigested and partly digested food in the stomach, ruins digestion and is also a no-no.
If you are not there already, it is best to adapt your diet progressively over time.