In general, healthy eating ingredients are found around the outer edges of most grocery stores, while the center aisles are filled with processed and packaged foods that aren’t good for you. Shop the perimeter of the store for most of your groceries (fresh fruits and vegetables, fish and poultry, whole grain breads and dairy products), add a few things from the freezer section (frozen fruits and vegetables), and visit the aisles for spices, oils, and whole grains (like rolled oats, brown rice, whole wheat pasta).
Fiber is an important part of an overall healthy eating plan. Good sources of fiber include fortified cereal, many whole-grain breads, beans, fruits (especially berries), dark green leafy vegetables, all types of squash, and nuts. Look on the Nutrition Facts label for fiber content in processed foods like cereals and breads. Use the search tool on this USDA page to find the amount of fiber in whole foods like fruits and vegetables.