350 Chapter 13 Nutrition Copyright Goodheart-Willcox Co., Inc. The basal metabolic rate (BMR) varies greatly from person to person. The BMR is higher while a person is growing. Thus, the BMR of children and teenagers is greater than that of adults. This is why people need to decrease the amount of food they eat when they get older. Older people do not need as many calories to sustain their body processes as younger people. Other factors, such as glandular secretions and body temperature, can affect your metabolic energy needs. For instance, when there is an undersecretion by the thyroid gland, basal metabolism is lower. When there is an oversecretion, basal metabolism is higher. The higher your body temperature is, the greater your metabolic needs are. Therefore, when you have a fever, your basal metabolism will be higher. Energy for Physical Activities Physical activity raises energy needs above basal requirements. Whenever you use your muscles, you use energy. The amount of energy you need is related to the amount of work you do. For instance, you need more energy to walk than to sit and rest. You need more energy to run than to walk. If your level of physical activity is light, you will need fewer calories to fulfi ll your energy needs. If you are very active, you will need more calories to meet your energy needs. Controlling Your Weight Weight management involves eating and physical activity. The foods you eat give your body energy, which is measured in calories. When you are active, you burn these calories. To control your weight, you need to compare the total calories eaten to the total calories used. How Much Should You Weigh? To set goals for weight management, you need to know what weight range is considered healthy for you. Health professionals determine this by using a calculation called body mass index (BMI). The BMI is very useful for measuring body fat. 13-16 Tomatoes, lettuce, and the other ingredients in this salad are high in water content and thus low in calories. Childhood Obesity Obesity rates among young children are rising. Children who are obese are more prone to problems in emotional and social development. They may show disruptive behavior or have trouble making friends. Mental Health Awareness