Depends on what you eat. Theres also stimuli to help stop nightmares. For me I can't eat oranges or anything sour before bed. My stimulus that help keep nightmares off my mind is a dream catcher. No it doesnt really catch your dreams, but it makes you think it does, thats what makes it a good stimulus for me.
Not necessarily, it may be that you just have a lot of nightmares. But eating after 7:00pm isn't good, it sits and your stomach and turns into all this fat. If you are hungry, try eating fruit, veggies, protein. STAY AWAY FROM THE CARBS. Such as bread, pasta, potatoes etc.