These foods—notably vegetables, fruits, legumes, and whole grains—should supply about 20 to 35 grams of dietary fiber a day, depending on your calorie needs. (Aim for 14 grams of fiber for every 1,000 calories, as advised by the Dietary Guidelines for Americans.) Fiber slows the absorption of carbohydrates, so they have less effect on insulin and blood sugar, and it provides other health benefits. Try to fill three-quarters of your plate with produce, legumes, and whole grains—leaving only one-quarter for meat, poultry, or other protein sources.
Your favorite childhood snack is good for your grown-up self, too. Because peanut butter is a great source of protein and healthy fats, it can curb hunger and keep you feeling full long after you're finished eating. Having small snacks during the day that include a lean protein such as peanut butter with complex carbs (like an apple or banana) can also help keep your metabolism running smoothly.