Energy Energy is needed to sustain body processes and for physical activity. Energy in food is measured in calories. Calories are supplied by fat, carbohydrate and protein. Vegetarians tend to consume fewer calories and are thinner than meat-eaters. This is because plant foods are bulky and low in calories.
Most vegetarians eat enough food to meet their energy needs.
Vegetarian children and adolescents will receive enough calories if their diets are well-planned. The less restricted the vegetarian diet, the easier it is to meet energy and nutrient needs. Protein Protein is needed for growth and maintenance of body tissues. It also is necessary for enzymes, hormones, antibodies and milk production in women who are breastfeeding. Plant sources of protein can provide adequate amounts of essential and nonessential amino acids, if they are reasonably varied and caloric intake is sufficient to meet energy needs.