Why did Prophet Muhammad forbid eating onions?

[Śrī Anil asked: The Messenger of Allāh (ﷺ) forbade eating of onions and leek. When we were overpowered by a desire (to eat) we ate them. Upon this he (the Holy Prophet) said: He who eats of this offensive plant must not approach our mosque, for the angels are harmed by the same things as men. Why did Muhammad object to the eating of onions? How can angel get harmed by eating onions when angels are energetic beings? In Hinduism also, some sects do not eat onion and garlic. How can we explain this common practice in the two religions?]

Swāmi replied: Overeating of some substances is not good for health. When one’s health is spoiled, one’s spiritual effort also gets spoiled. When human beings become weak in the spiritual line, angels get discouraged because the weakness of humanity in spirituality leads to the disturbance of world peace. Here, the word ‘harming’ should not be taken in its direct sense, here. If we restrict something, people will consume it in a lesser quantity. If we do not restrict it at all, human beings will consume it in a larger quantity. This is the ‘(n-1) rule’, which is restricting something completely, so that it will be consumed in a moderate quantity. The taste of some foods makes one consume those foods in a larger quantity, but one’s consumption must be based on health and not on taste.