Nutrition is the science of food and nutrients, and how they interact with the body. Diet is the nutrients that are ingested into the body; dieting is the act of purposely consuming or restricting types and/or amounts of food temporarily over a period of time. A diet that matches one's lifestyle can provide energy, help maintain weight, and prevent or reduce the risk of diseases and illnesses. Read more

Physical activity is any movement of the body that requires energy. An active lifestyle that includes aerobic activity, strength training, and stretching can benefit the heart, lungs, and muscles, and lower the risk of disease. Exercise and fitness can contribute to greater levels of physical health. Physical activity is directly connected to mental health by influencing mood and stress. Read more

Sleep is essential to the maintenance of overall physical health by boosting the immune system and regulating hormones. Proper sleep can influence the prevention or development of disease, high blood pressure, infection, obesity and weight gain, and stroke. Sleep is directly connected to the intellectual, mental, occupational, and social dimensions of health. Read more

Medical health is the science of medicine and the treatment of illness and injury to the physical body. The “medical model” of health focuses on diagnosing, monitoring, and treating disease through observation, testing, and data collection. Factors influencing medical health include drug use, environment, genetics, nutrition, hygiene, physical activity, sexual activity, sleep, smoking and other risky behaviors, and stress. Read more

The appearance of the human body refers mainly to observable surface attributes. Physical appearance includes genetic traits such as body size and shape, hygienic traits such as cleanliness, and elements of personal expression such as body language and style of clothing and other accessories. Other physical and behavioral factors impact appearance, which in turn can affect the mental, social, and occupational dimensions of health. Read more

Stress is the brain's response to a stimulus and can be caused by interactions with the environment. The reaction triggered is called the "fight or flight" response, and  can be caused by positive stress (eustress) or negative stress (distress). The effect of stress on the body depends upon the frequency, intensity, and duration of the stress. The long-term effects of prolonged and intense stress can cause serious health conditions, and can be potentially fatal. Read more