The United States Food and Drug Administration recommends that adults and teenagers get three and a half to six and a half servings of fruits or vegetables per day. Children age five to 12 need 2.5 to 5 cups per day. These ranges are based on sedentary to active lifestyles. Dried fruit contain fiber, and the USDA recommends adults consume at least 25 g per day. One ounce of walnuts meets the RDI for omega-3 fatty acids. According to "The Wall Street Journal: Health," eating 1.5 oz. of nuts per day reduces risk of heart disease, but 2.5 oz. significantly lowers triglycerides and cholesterol levels.