The moment when you are standing in front of a ruined dinner and a mess in your oven may not be the time to ask why you need to pierce potatoes before you bake them. From the time you were a child, you likely saw your parents pierce potatoes with a fork or knife before baking them for your dinner, but didn't know why.

Fruits and vegetables are the cornerstone of the Nutrisystem diet; you cannot do the diet without eating them. Consuming fruits and vegetables is associated with a lower incidence of diabetes, which is important for obese dieters who are at risk for diabetes.

Watermelon is a “vitamin” food. One serving per day provides a healthy dose of Vitamin A and C, a good helping of vitamin B6 and higher levels of the carotenoid lycopene than any other fruit or vegetable.

Capsaicin is a chemical compound found in varying amounts in chili peppers. When it comes in contact with your skin or mucous membranes it produces a burning sensation.

The United States produced more than 32 million pounds of tomatoes in 2009, according to the U.S. Department of Agriculture. Although the versatile tomato is horticulturally a fruit, most people use tomatoes as a vegetable in salads or Italian dishes.

Most fruits and vegetables are both pretty and nourishing. A plump tomato on the vine is an invitation — to make salsa, create a salad or liven up a sandwich. While it’s still on the vine, most people would undoubtedly think of that tomato as alive, but in fact, even after picking, fruits and vegetables remain alive.

Bell peppers are a staple in most grocery store produce sections. You may have had bell peppers roasted, steamed or added to a stir-fry. But you don't have to cook bell peppers to reap their health benefits and bright, slightly tangy flavor.

Malabar spinach has stiff, slightly spongy leaves reminiscent of chard. Because of its texture, it's best used cooked rather than in salads. Malabar spinach, also called Mong Toi, originates in India, where it readily grows on vines.

Celery contains certain toxins called psoralens with potentially carcinogenic effects and goitrogens with potentially anti-thyroid effects. Celery is also one of the vegetables highest in pesticide content, unless it is organically grown, and is vulnerable to a kind of mold called mycotoxins.

Spaghetti squash is easy to prepare and can be used as a pasta substitute for low-carbohydrate and gluten-free diets. This big, yellow, oval squash has flesh that comes out in long strings like spaghetti noodles when fully cooked.

Spinach is a dark green, leafy vegetable that is packed full of nutrition. It can be eaten raw or cooked and served as a side dish, but it has also found its way to the center of main dishes. Spinach is a versatile vegetable, needs very little seasoning and is low in calories.

Sweet potatoes are a good food choice for diabetics as they are high in fiber and have a low glycemic index. Foods with a low glycemic index have less of an immediate impact on blood glucose levels, and therefore can help diabetics control their blood sugar.