Fruits and vegetables are widely recommended for their health benefits, with the Dietary Guidelines for Americans 2010 suggesting that half of each plate should consist of these foods. They provide a diverse range of nutrients, including dietary fiber, vitamins, minerals, and phytochemicals, which have protective effects against chronic diseases. Fiber, in particular, is linked to lower risks of cardiovascular disease and obesity. This review summarizes existing dietary guidelines, attempts to classify fruits and vegetables based on chemical structures and functions, and details their nutrient composition. It also reviews epidemiological and clinical studies on the health benefits of fruits and vegetables, emphasizing the role of fiber in disease prevention. Fruits and vegetables vary in nutrient content, with some being high in fiber, others in starch, and some in carotenoids. Dietary fiber is essential for digestive health and is found in many fruits and vegetables, though its concentration varies. The classification of fruits and vegetables into color categories is not always aligned with their nutrient content. Fiber is generally divided into soluble and insoluble types, with soluble fiber having beneficial effects on serum lipids and insoluble fiber aiding in digestion. However, the scientific evidence supporting these distinctions is inconsistent. The Institute of Medicine recommends dietary fiber intake based on energy consumption, with higher recommendations for those consuming more energy. However, average fiber intake in the U.S. is far below these recommendations. Fiber sources include whole grains, legumes, and dried fruits, but many processed foods are low in fiber. The health benefits of fruits and vegetables are supported by their high fiber, vitamin, and mineral content, as well as their phytochemicals. However, the specific benefits of individual fruits and vegetables are not well established. Studies suggest that fruits and vegetables can affect satiety, with whole foods being more satiating than processed forms. Fiber in drinks may be less effective than in whole foods in enhancing satiety. Overall, fruits and vegetables are important for health due to their nutrient content and fiber, and their consumption should be encouraged to improve dietary quality and reduce chronic disease risk.Fruits and vegetables are widely recommended for their health benefits, with the Dietary Guidelines for Americans 2010 suggesting that half of each plate should consist of these foods. They provide a diverse range of nutrients, including dietary fiber, vitamins, minerals, and phytochemicals, which have protective effects against chronic diseases. Fiber, in particular, is linked to lower risks of cardiovascular disease and obesity. This review summarizes existing dietary guidelines, attempts to classify fruits and vegetables based on chemical structures and functions, and details their nutrient composition. It also reviews epidemiological and clinical studies on the health benefits of fruits and vegetables, emphasizing the role of fiber in disease prevention. Fruits and vegetables vary in nutrient content, with some being high in fiber, others in starch, and some in carotenoids. Dietary fiber is essential for digestive health and is found in many fruits and vegetables, though its concentration varies. The classification of fruits and vegetables into color categories is not always aligned with their nutrient content. Fiber is generally divided into soluble and insoluble types, with soluble fiber having beneficial effects on serum lipids and insoluble fiber aiding in digestion. However, the scientific evidence supporting these distinctions is inconsistent. The Institute of Medicine recommends dietary fiber intake based on energy consumption, with higher recommendations for those consuming more energy. However, average fiber intake in the U.S. is far below these recommendations. Fiber sources include whole grains, legumes, and dried fruits, but many processed foods are low in fiber. The health benefits of fruits and vegetables are supported by their high fiber, vitamin, and mineral content, as well as their phytochemicals. However, the specific benefits of individual fruits and vegetables are not well established. Studies suggest that fruits and vegetables can affect satiety, with whole foods being more satiating than processed forms. Fiber in drinks may be less effective than in whole foods in enhancing satiety. Overall, fruits and vegetables are important for health due to their nutrient content and fiber, and their consumption should be encouraged to improve dietary quality and reduce chronic disease risk.