Doctors agree that onions are healthy, but eating them at night can affect sleep differently from person to person. For some, they may trigger reflux and restlessness. For others, especially when cooked, onions may have no negative effect—or may even support relaxation.
The key is listening to your body. If onions disrupt your sleep, move them to
lunchtime. If you tolerate them well there’s no need to eliminate them entirely.
As with many foods, timing and preparation matter just as much as nutrition.