Energy Balance and Body Composition

1. Energy Balance and Body Composition- FON 241; L. Zienkewicz Energy Balance and Body Composition Chapter 8

2. Energy Balance and Body Composition- FON 241; L. Zienkewicz Energy Balance 1. Positive energy balance: Energy IN > Energy OUT result: stored in adipose tissue * necessary during pregnancy, growth. 2. Negative energy balance: Energy IN < Energy OUT result: weight loss We are constantly “spending energy” and refuel periodically by consuming food and beverages. In Positive energy balance, energy intake is greater then energy output. This is necessary in growing children, pregnant women, etc where growth is needed. However, in adults, a positive energy balance leads to creeping weight gain, adipose tissue is primarily affected. Weight loss occurs in negative energy balance. But unlike positive energy balance… adipose tissue is not the only tissue affected: both adipose tissue and lean tissue are afected.We are constantly “spending energy” and refuel periodically by consuming food and beverages. In Positive energy balance, energy intake is greater then energy output. This is necessary in growing children, pregnant women, etc where growth is needed. However, in adults, a positive energy balance leads to creeping weight gain, adipose tissue is primarily affected. Weight loss occurs in negative energy balance. But unlike positive energy balance… adipose tissue is not the only tissue affected: both adipose tissue and lean tissue are afected.

3. Energy Balance and Body Composition- FON 241; L. Zienkewicz Weight Maintenance: Energy IN = Energy OUT Energy needs are met by food intake.Energy needs are met by food intake.

4. Energy Balance and Body Composition- FON 241; L. Zienkewicz Determining Energy Composition Bomb calorimeter. Burns food and measures the amount of heat given off: this is a direct measure of food’s energy value. Chemical bonds break and release energy. 1kcal= energy required to increase 1kg water 1oC. A bomb calorimeter measures the available energy in foods but overstates the amount of energy that the human body derives in food : Remember 25% is actually used as energy, the remaining 75% is given off as heat. A portion of food is burned inside a chamber of the calorimeter that is surrounded by water.The food burns, gives of heat and raises the temperature of the water surrounding the chamber. After the food has burned, the temperature of the water is taken. This number represents the energy amount in food. How else can energy needs be estimated? Compute energy by calculating the amount of carbs, protein and fat in food (4,4,9). A bomb calorimeter measures the available energy in foods but overstates the amount of energy that the human body derives in food : Remember 25% is actually used as energy, the remaining 75% is given off as heat. A portion of food is burned inside a chamber of the calorimeter that is surrounded by water.The food burns, gives of heat and raises the temperature of the water surrounding the chamber. After the food has burned, the temperature of the water is taken. This number represents the energy amount in food. How else can energy needs be estimated? Compute energy by calculating the amount of carbs, protein and fat in food (4,4,9).

5. Energy Balance and Body Composition- FON 241; L. Zienkewicz