After dinner snack that would not break your diet.
Popcorn has a good glycemic index (GI) of 55.  It contains no cholesterol, it is virtually fat-free (only 0.1 g per cup) and contains only 100 to 150 calories in a serving of five popped cups. Popcorn also has a number of essential vitamins including: folate, niacin, riboflavin, thiamin, pantothenic acid and vitamins B6, A, E and K.  A serving of popcorn contributes about 8-percent of the daily value of iron, with lesser amounts of calcium, copper, magnesium, manganese, phosphorus, potassium and zinc.
Popcorn is a good snack for diabetics as it does not impact blood sugar levels.  Additionally, the USDA Agricultural Research Service says “low GI diets have proven health benefits. They improve both glucose and lipid levels in people with type 1, as well as type 2, diabetes. Because they are slowly absorbed, they help in weight control because they help control appetite and delay hunger. Fiber is good for diabetics because research suggests that it helps to control blood sugar levels by slowing gastric emptying.”