Eating fruits and vegetables at every meal (at least five, half-cup servings a day) helps you feel full without excess fat and sugar. Bite-for-bite, plant foods contain fewer calories than sugary snacks and many calorically dense, overly processed foods. Those kinds of heavily processed foods contribute to obesity and increase susceptibility for serious diseases, such as diabetes and cancer (Barclay et al., 2008).
Phytochemicals or phytonutrients are natural compounds in all plant foods that are believed to give the people who eat them protection from an array of diseases, such as various forms of cancer and cardiovascular disease (ADA, 2009) These compounds exist in plants to serve a function for the plant, such as UV protection or color. The benefits of consuming phytochemicals seem to be more prominent when consumed in whole foods, such as fruits, vegetables, and whole grains, rather than in supplement form, as phytochemicals appear to have synergistic effects (AND, 2013).
There are several classes of phytochemicals and the different compounds provide different benefits. For example, certain phytochemicals in the carotenoid group, lutein and zeaxanthin, are found in the retina of the eye and are believed to play a role in preventing macular degeneration as we age (Linus Pauling Institute, 2013). In addition, foods containing polyphenols offer antioxidant properties, which can provide UV protection and protect cells from damage that can lead to cancer (Dinkova-Kostova, 2008). It’s never too early to reap the benefits of phytonutrients in order to prevent degenerative disease later in life.
Eating plenty of vegetables, fruits, whole grains, and beans gives our bodies fiber, a nutrient known to protect against colon cancer. Getting enough fiber, along with adequate hydration, also promotes regular bowel movements and prevents uncomfortable, sometimes painful, constipation.
Fiber also promotes satiety, which can prevent overeating and weight gain. For example, fiber-rich whole grains, such as oats, whole-wheat, brown rice, millet, and quinoa, are digested more slowly than refined foods, so you will feel full longer. In contrast, quickly digestible and highly-processed foods, such as white bread, potato chips, and candy are easy to overeat. Choosing fiber-rich whole grains rather than refined grains helps maintain blood sugar levels and provides the brain with a steady fuel source. This promotes satiety, mental focus, and physical performance (Kanaerek et al., 2005). Choosing whole grains also provides vitamins and minerals that are lost in the refining process.
Here are the daily requirements of fiber for different age groups of young children (USDA, 2013):
All plant foods, from apples to walnuts, have different vitamins and minerals. Here are just a few examples of some key vitamins and minerals found in plant foods and some of their food sources (Linus Pauling Institute, 2013):