Approximately 70% of U.S. adults do not participate in the recommended 30 minutes of moderate physical activity per week 49 . Of this portion, 24% report no physical activity 49. Sedentary individuals can experience a decrease in risk of death and disease with physical activity 8. Further, exercise can help prevent obesity from hypokinesis (lack of regular physical activity).
To understand how exercise can prevent obesity, it is important to understand the concept of energy expenditure versus energy intake and how the sum of these two variables can affect weight. Additionally, it should be appreciated that physical activity is an important factor for determining energy expenditure.
Energy expenditure (i.e.- the amount of calories burned) is dictated by the metabolic demands of the body 33. Physical activity increases the body’s metabolic demands and is therefore a primary contributor to energy expenditure. Energy intake is determined by the amount of calories absorbed from food consumption 33. When the amount of calories an individual expends is equal to the amount they absorb from consuming food, they should maintain a steady weight 33. When an individual expends more calories than they absorb from food, weight loss may occur 33. Conversely, when an individual absorbs more calories then they expend, weight gain may occur.
Summary of energy expenditure and energy intake
Over the past thirty years, the prevalence of obesity in the U.S. has increased 23. Concurrently, physical activity levels have decreased. This along with wide-spread changes of diet may be key contributors to the obesity epidemic.
To prevent weight gain, energy expenditure should be greater than or equal to energy intake. A healthy lifestyle involving physical activity can contribute to increased energy expenditure, weight maintenance and physical fitness 33,62. To provide guidance for the public and health/fitness professionals, the American College of Sports Medicine (ACSM) has set up guidelines and recommendations for quantity and quality of exercise.
|Activities of Daily Living
Activities of daily living (ADL) refer to the basic tasks of everyday life 78. Some examples include walking around the house, performing regular household chores (washing the dishes, vacuuming, etc.), bathing, raking up leaves in the yard, etc. The sum of such activities throughout the day comprises an individual’s ADL level. Another factor that affects ADL is the mode an individual utilizes to complete a task.
Examples for Increasing ADL
Numerous activities that were once accomplished manually now are frequently completed via an automated alternative 47 . Many examples for increasing ADL, including those listed above involve replacing an automated task with a manual task whenever possible. Although some of the activities may burn more calories than others, the frequency and accumulation of ADL is important for gross energy expenditure.
Eating healthy can help reduce cholesterol levels, blood pressure, and excess body weight 39 . A diet that provides adequate macro and micronutrient balance as well the appropriate caloric intake can help prevent obesity 39.
AHA Eating Plan for Healthy Americans
Following this eating plan aids in the achievement and maintenance of a healthy eating pattern. Benefits of a healthy eating pattern include having a healthy body weight, desirable blood cholesterol level, and normal blood pressure. Every meal does not have to meet all of the guidelines. It is important to apply the guidelines to the overall eating pattern of several days. These guidelines may do more than improve heart health. They may reduce the risk for other chronic health problems including, type 2 diabetes, osteoporosis (bone loss), and some forms of cancer.