A. No. But drinking alcohol or caffeine, which can disrupt sleep, might. Same goes for eating fatty or spicy foods before bed, which can cause indigestion, leading to fitful rest and possibly scary dreams. (We dont know why disrupted sleep can bring on nightmares.)
There is one connection between sugar and nightmares: Low blood sugar, or hypoglycemia, can trigger temporary brain-chemistry changes, which may cause strange dreams. If youre hypoglycemic (telltale signs include shakiness, sweating, or confusion), its actually important to eat a bedtime snack to maintain your blood sugar level through the night. Try some yogurt with granola or a graham cracker with peanut butter; both snacks contain carbs to boost your blood sugar, plus protein to keep it from crashing.