| Everyone eats food differently too. Like when I eat pistachios I usually have 5-6 at a time, as I like them, but I was never a nut person, and mostly just eat them now as they're a good carb-free snack. Other people I know though are liable to have 20-30 when they dig in. So it definitely depends on the person. I know for me with grapes I don't usually have more then about 8-10 just because that is my preference. (other foods like pizza I know I have far worse tendencies then the average person!) Test and see is probably the best advice. | 
