Understanding Nutrition. Chapter 8 - Energy Balance and Body Composition By A. Fellah, Ph.D. Energy Balance. When energy in balances with energy out, a person’s body weight is stable. For each 3500 kcal eaten in excess, a lb of body fat is stored.
Chapter 8 - Energy Balance and Body Composition
A. Fellah, Ph.D.
When energy in balances with energy out, a person’s body weight is stable.
For each 3500 kcal eaten in excess, a lb of body fat is stored.
The rate of wt. loss for overweight people is 0.5-2 lbs a week or 10% of body weight over 6 months.
A cascade of regulation: hunger, appetite, satiation, and satiety
Physiological influences, sensory influences, and cognitive influences.
Postingestive influences and postabsorptive influences.
Satiety Scores of Foods
For the same size serving, peanuts deliver more than 15 times the kcalories and 20 times the fat of popcorn.
Popcorn offers twice the satiety of peanuts. For the same number of kcalories, a person can have a few high-fat peanuts or almost 2 cups of high-fiber popcorn. (This comparison used oil-based popcorn; using air-popped popcorn would double the amount of popcorn in this example.)
Components of Energy Expenditure:
The energy needed to maintain life when a body is at complete digestive, physical, and emotional rest.
3. Thermic Effect of Food: (TEF)
4. Adaptive Thermogenesis:
Components of Energy Expenditure
Each of these structures is made of 8 blocks. They weigh the same, but they are arranged differently. If you were to count the sides of these structures, you would find that the short, wide one has 24 sides and the tall, thin one has 34.
Because the tall, thin structure has a greater surface area, it will lose more heat (expend more energy) than the short, wide one.
Similarly, two people of different heights might weigh the same, but the taller, thin one will have a higher BMR (expending more energy) because of the greater skin surface.
Body weight = fat + lean tissue (including water).
BMI = weight (kg)
BMI values and health risks
The Effects of Body Weight and Smoking
Both underweight and overweight present risks of a premature death. This J-shaped curve describes the relationship between body mass index (BMI) and mortality and shows that optimal BMI is between 21 and 25 (some researchers extend this range from 19 to 27).
The assessor measures body fat by using a caliper to gauge the thickness of a fold of skin on the back of the arm (over the triceps), below the shoulder blade, and in other places (including lower body sites) and then compares with standards.
The assessor measures body density by weighing the person first on land and then again while submerged in water.
The difference between provides a measure of the body’s volume.
A mathematical equation using the two measurements allows to calculate body density’ from which the percentage of body fat can be estimated
The assessor measures body fat by using a low-intensity electrical current. Because electrolyte-containing fluids, which readily conduct an electrical current, are found primarily in lean body tissue, the leaner the person , the less resistance to the current. The measurement to electrical resistance is then used in a mathematical equation to estimate the percentage of body fat.