Calories

1
Unit 8

• Calories!
• Food, Energy,
• and Energy Balance

2
Calories are a unit of measure

• Used to express the amount of energy produced by
  foods in the form of heat
• Calories are actually kilocalories or kcals
• the amount of energy needed to raise the
  temperature of kilogram of water one degree
  Celsius.
• 1 kcal or calorie 1 kilojoule

3
How do they determine the caloric value of foods?

• Bomb calorimeter
• Burn the food entirely and measure the increase
  in temperature of the surrounding water
• Heat released by the food is approximately the
  same as the energy it supplies for the body

4
The body needs energy

• Fuel muscular activity
• Growth
• Tissue repair and maintenance
• Chemically process nutrients
• Maintain body temperature
• Many other uses

5
Types of energy use

• Basal Metabolism
• Energy required to maintain normal body functions
  while at rest
• Physical activity
• Energy needed for muscular work
• Dietary thermogenesis
• Energy used to chemically process foods (process
  gives off heat)

6
Basal Metabolism

• Measure of the energy used when a body is in a
  state of complete rest
• Estimate your basal metabolic rate
• Men body weight (lbs) times 11
• Women body weight (lbs) times 10
• 170 lb man X 11 1870 cals/day
• 135 lb woman X 10 1350 cals/day

7
Physical Activity

• Amount spent depends on activity level
• Inactive 30 of basal metabolism calories
• Average 50 of basal metabolism calories
• Active 75 of basal metabolism calories
• Example if basal metabolism 1500
• Inactive person 1500 X .30 450 calories
• Average person 1500 X .50 750 calories
• Active person 1500 X .75 1125 calories

8
Activity level often overestimated

• Dont count time getting ready or breaks or
  timeouts

9
Dietary thermogenesis

• Digesting food
• Absorbing food
• Utilizing nutrients
• Transporting nutrients to cells
• Energy escapes as heat
• Estimated at 10 of total calories

10
Adding it all up

• Total daily need for calories
• Basal metabolic rate 1500
• Activity (inactive) 450
• Dietary thermogenesis 195
• TOTAL 2145 calories

11
Where is the energy in foods?

• Carbohydrates 4 cal/gram
• Proteins 4 cal/gram
• Fats 9 cal/gram

12
Which food has the most calories?

• 1 Tablespoon margarine
• 1 Tablespoon sugar
• 1 Tablespoon steak

13
Which food has the most calories?

• 205 calories
• 420 calories
• 118 calories

• Half-cup peanuts
• Medium-sized potato
• One cup rice

14
Which food has the most calories?

• 205 calories
• 420 calories
• 118 calories

• Half-cup peanuts
• Medium-sized potato
• One cup rice

15
Most foods are a mixture

• Quarter- pound hamburger
• 32 gm protein
• 39 gm carbohydrate
• 32 gm fat
• Total calories 576

16
How is caloric intake regulated by the body?

• Hunger unpleasant physical and psychological
  sensations that lead people to acquire and ingest
  food
• Satiety a feeling of fullness or of having had
  enough to eat
• Appetite the desire to eat a pleasant sensation
  that is aroused by thoughts of the taste and
  enjoyment of food

17
Energy Balance

• Energy intake energy need
• Weight remains stable

18
Negative Energy Balance

• Energy intake is less than energy need
• Weight loss

19
Positive Energy Balance

• Energy intake is more than energy need
• Weight gain