I know of 3 children, ages around 7, 9, 14 who had their gallbladders remove because of sandy material, in this case it was hereditary. The other child didn't but is eating only non fat foods and has a very healthy lifestyle, otherwise there would be troubles. I don't think age is an issue, although people over 40 probably do have stones. I'm not overweight, and never have been, I weight 155 lbs, but I have eaten tons of butter, chips, fries, bacon, so on, and no one else in my family have them. Plus I'm a guy, what gender are you? Females tend to get stones more than men for some reason, but its not a hard rule of thumb of course.