Topic 1: Energy budget

Question 1

Define energy balance (1 point)

Answer 1

1. the energy taken into the body (energy input) in diet EQUALS the energy used by the body (energy output)

Question 2

Define energy imbalance (1 point)

Answer 2

1. the energy taken into the body in diet DOES NOT EQUAL the energy used by the body

Question 3

Key Summary: What are the consequences of energy imbalance? (3 points)

Answer 3

1. {WEIGHT GAIN/OBESITY}
   - energy input EXCEEDS energy output (energy used by the body):
   - excess energy stored as FAT (and glycogen)
   - BMI INCREASES
   - can lead to OBESITY (BMI equal to or above 30)
2. WEIGHT LOSS
   – if energy output (used by the body) EXCEEDS energy input
3. Can lead to MALNUTRITION
   (from lack of protein – reduces muscle mass, mobility and stamina), gallstones, tiredness, dehydration, constipation, irritability and depression.

Question 4

Key Summary: List the {consequences of obesity/high BMI} (5 points)

Answer 4

1. High blood pressure - can damage the endothelium of the artery WALL increasing the risk of atherosclerosis
2. High BLOOD cholesterol levels - increase risk of atheroma’s forming leading to atherosclerosis which narrows the LUMEN of arteries
3. INCREASED RISK of heart attack/CHD (coronary heart disease) caused by the narrowing of the coronary arteries – increased risk of blood clot BLOCKING them and reducing blood flow and oxygen to heart muscle
4. Increased risk of a stroke due a reduced BLOOD FLOW AND OXYGEN to brain tissue
5. Increased risk of type II diabetes due to reduced sensitivity of insulin receptors

Question 5

What are obesity indicators used for? (1 point)

Answer 5

1. Doctors use obesity indicators like BODY MASS INDEX (BMI) to work out whether a person is obese or overweight, to assess their risk of developing CVD

Question 6

How do you calculate body mass index (BMI)? (give the formula)

What are the units of BMI?

Answer 6

divide body mass in kg by height in m^2

(height in m)^2

kg/m^2 
OR 
kg per m^2 
OR 
kg m^-2

Question 7

How do you calculate waist-to-hip ratio? (give the formula)

The units used in w-t-h ratio need to be ___ _____.

Answer 7

divide waist circumference by hip circumference

hip circumference

the same

Question 8

(Doctor’s advice if overweight or obese)
Key Summary: Lose weight to reduce BMI by…

• Increasing exercise: (explain it, 4 points)

To reduce risk of coronary heart disease + type II diabetes

Answer 8

Increasing exercise:

1. body uses more energy than is being consumed in diet, which increases weight loss
2. increases metabolic rate
3. increases muscle tissue which uses more energy than fat
4. the {longer/more intense} the exercise, the more energy is {used/more weight lost}

Question 9

(Doctor’s advice if overweight or obese)
Key Summary: Lose weight to reduce BMI by…

• Decreasing energy intake in diet: (explain it, 1 point)

To reduce risk of coronary heart disease + type II diabetes

Answer 9

Decrease energy intake in diet
1. reduce {carbohydrates in diet / reduce alcohol intake / reduce sugars in diet/ reduce fat in diet} - which increases weight loss

Question 10

Key Summary: What to energy requirements depend on?

3 things, explain each

Answer 10

1. AGE – more energy required during 0-18 when growing, lower energy required during old age
2. BODY SIZE – larger body requires more energy, as more body cells to supply
3. ACTIVITY LEVEL – more active lifestyle requires more energy for extra activity