If you’re looking for a serious answer, not at all. Snacking all day is the opposite of fasting. Just because it’s small doesn’t mean it’s not food.
If he actually didn’t eat all day and then had a huge meal at night, that would be it. That would also be called OMAD (one meal a day), which is a type of intermittent fasting.
The whole body doesn’t match. Those must be some stupid-ass aliens.