Answer to Question 1
A person's weight does not provide information about body compositioni.e., lean muscle mass, body fat, and body water. It would be particularly helpful to assess body composition, as it changes throughout the life cycle and is affected by health status, diet, and overall energy balance. It is possible for physically fit people to weigh more and appear overweight or obese when they are actually lean. Muscle is more dense than fat; thus, the more muscle mass a person has, the more dense he/she will be and the more he/she will weigh.
Answer to Question 2
Total energy expenditure (TEE) takes into account three components: (1) basal metabolism, (2) physical activity, and (3) thermic effect of food. As it is too difficult to measure basal metabolism because of the stringent conditions required, resting metabolic rate (RMR) is often used. RMR expressed over 24 hour period = resting energy expenditure (REE). The Harris-Benedict Equation can be used to calculate REE. The DRIs developed by Institute of Medicine include calculations for Estimated Energy Requirements (EERs) that take into account TEE and energy to support growth. EERs for adults are intended for weight maintenance. Adjustments in energy intake and physical activity can be made to support weight loss or gain.
Thorax Anterior view of human body
Body fluid compartments
Important Trace Elements in the Body
The dorsal-column medial-lemniscus system. The pathways from only one side of the body are shown.
Your Body Digests, Absorbs, and Synthesizes Protein
Heat Loss by the Body