Lecture 6 - Positive Energy Balance and Exercise

Question 1

What are the main regulators of food intake at the level of the GIT?

Answer 1

CCK, GLP-1, PYY3-36, Ghrelin

Question 2

What are the main regulators of food intake at the level of the fay/energy stores?

Answer 2

Leptin, adipolectin, resistin

Question 3

What are the neural regulators of food intake at the level of the GIT?

Answer 3

Gastric distension (mechanoreceptors)

Question 4

What are the main regulators of food intake at the level of the brain?

Answer 4

Melanocortins, NPY, AgRP, Oxyrens

Question 5

What stimulates leptin release from fat stores?

Answer 5

dec. O2, insulin (fed state), cortisol (during stress), interlukins-1,6 (inflammation), neural stimulation

Question 6

What are the following classified as: leptin, adiponectin, resistin, TNF-a, IL-6

Answer 6

Adipokines

Question 7

What inhibits leptin release from fat stores?

Answer 7

neuropeptide-Y (NPY)

Question 8

What are the effects of leptin?

Answer 8

suppresses appetite, increase metabolic rate, inhibits NPY

Question 9

What are the effects of NPY?

Answer 9

Increases appetite (brain) and decreases SNS effect on metabolic rate

Question 10

What can mutations of the Ob gene do?

Answer 10

Can cause low levels of leptin to be produced and cause obesity - this is because the Ob gene codes for leptin

Question 11

Describe the effect on hypertrophy and hyperplasia on fat cells through development

Answer 11

Hypertrophy: 1-6: 75%, 13+: 100%. Hyperplasia: 0-1: 3x birth level, 1-10: gradual increase, 10-20: rapid increase

Question 12

What risk is an adult at for obesity if they have a high fat mass as a child

Answer 12

3 times

Question 13

What risk is an adult at for obesity if they have obese parents

Answer 13

3 times

Question 14

If you could only choose one, would exercise or diet be more efficacious in creating a long term, sustainable net deficit?

Answer 14

Energy deficits created by diet alone had greater effects on appetite (and ad libitum energy intake) than exercise alone

Question 15

What is the most important factor for creating a net energy deficit?

Answer 15

Most important factor is consistency

Question 16

What are the FIIT principals for creating an energy decifit (per week?)

Answer 16

Frequency
• ≥5 days per week
• Recommend daily activity
Intensity
• Moderate-intensity continuous or high-intensity intervals (whichever more sustainable)
Duration
• 30min or 60min daily if walking
• Longer duration usually associated with faster weight loss
Type
• Mainly aerobic combined with modest amounts of resistance training

Question 17

If someone eats at their BMR and exercises 3 time per week, expending 300cal per session. How long would it take to lose 1kg of body fat?

Answer 17

– 1 kg body fat has 32,760 kJ energy (~900cal)
– Results in weight loss of 1 kg every 8-9 weeks

Question 18

Is exercise alone the best way to lose weight?

Answer 18

Exercise is not a quick way to lose weight
– It can be effective over the long term
– It is more effective at maintaining weight loss (weight and body fat loss)
– Combination of diet and exercise is usually optimal!

Question 19

What are some of the ways we determine obesity?

Answer 19

1. % body fat
2. Waist circumference
3. Hip circumference
4. Waist:hip ratio
5. Waist:height ratio
6. Body mass index (BMI)
7. BMI plus waist
8. Fat Mass Index (FMI)

Question 20

Is there a better test than BMI to test for obesity and body composition? Why?

Answer 20

BMI plus waist. An overweight BMI may not reflect fat mass for athletes
with larger muscle mass

Question 21

What are the BMI percentile values for underweight, overweight and obese?

Answer 21

• Underweight: < 5th percentile
• Overweight: 85th-95th percentile
• Obesity: > 95th percentile

Question 22

What environmental factors contribute to obesity?

Answer 22

– Diet
– Lack of physical activity

Question 23

What genetic factors may contribute to obesity?

Answer 23

Leptin resistance