Does eating a large or main meal late at night have any negative health or nutrition effects?

That's a great question! A similar question was answered here on tips for late night meals. 

In addition to what is answered on the above link, eating late at night right before bed can lead to some health concerns. Most people aren't as active at night as they are during the day. Your body rests in bed and does not use food as energy like it does during the day when you are more active. Those extra calories can be stored in fat cells, which can lead to weight gain or lead to poor digestion. To help digestion, try going on a walk after dinner or sitting up and reading a book.

Best of luck!