strawberries and blueberries taste really good, are low in calories, and fill your stomach a lot more than most pre-processed high calorie snacks (i've been trying to lose more weight lately). whenever i get peckish now, i just get 200 grams of strawberries in a bowl, and it fills me up entirely, and that alone is only like 60 calories. you could also try other things like oranges and apples, but those are a bit higher in sugar.