In everyday usage, a vegetable is any part of a plant that is consumed by humans as food as part of a savory meal. The term vegetable is somewhat arbitrary, and largely defined through culinary and cultural tradition.
Before the advent of agriculture, humans were hunter-gatherers. They foraged for edible fruit, nuts, stems, leaves, corms and tubers, scavenged for dead animals and hunted living ones for food.
Vegetables play an important role in human nutrition. Most are low in fat and calories but are bulky and filling.They supply dietary fibre and are important sources of essential vitamins, minerals and trace elements.
Particularly important are the antioxidant vitamins A, C and E. When vegetables are included in the diet, there is found to be a reduction in the incidence of cancer, stroke, cardiovascular disease and other chronic ailments.