My goal is losing some belly weight. Is it good or is it bad to have fruits as snacks?
Although the sugar is not processed or added it is still sugar.
Weight Loss
It not so much about the food you consume. It about the quantity...
Calories In, Calories Out
Thus, the key to increasing or decreasing body weight is dependent upon being in a calorie surplus or deficit.
An excellent example is...
Twinkie diet helps nutrition professor lose 27 pounds - CNN.com
Mark Haub, a professor of human nutrition at Kansas State University illustrated "Calories In, Calories Out" was the fundamental principle to weight loss by consuming a "Low Calorie Junk Food Diet"; consuming Twinkies, Cookies, etc.
Haub lost 27 lbs by decreasing his calories.
Fruit
Fruit is composed of Sugar.
Sugar is composed of Glucose and Fructose.
Most fruit is fibrous. There aren't many calories in it, fiber slows down digestion, and fill you up. That means it hard to over eat; as pet and oscar noted.
Thus, having some fruit isn't a problem.
Take Home Message
Any deficit diet in which your burn more calories than you take in will decrease your body fat/body weight.
Mark Haub's "Twinkie Diet" make that clear.
Haub went to state that he does NOT recommend the "Twinkie Diet" or anything like it.
Kenny Croxdale