Effects of Exercise and Restrained Eating

Behavior on Appetite Control Vanessa Kinan

Introduction

• Increase in the consumption of energy-dense food + reduction in physical activity = OBESITY

Appetite is regulated by multiple factors 1. the brain and various hormones2. different types of external stimuli • environmental• psychological• social• cultural

RationaleHow do increased amounts of physical activity (energy expenditure) and restrained eating (energy intake) effect appetite control thus decreasing an individuals overall energy intake?

• Effects of acute exercise on appetite, energy intake, and energy balance

• Effects of chronic exercise on energy intake, energy balance, and body weight

• Effects of exercise on appetite control

• Effects of exercise on appetite-related hormones

Method

• 25 unrestrained, normal-weight sedentary individuals (11 male, 14 female)

• 6-week moderate- intensity exercise intervention• Baseline and end of the intervention were examined• Gave one group a high energy preload (HEP) and the other group a

low energy preload (LEP)• Measured the following

1. Energy intake (kJ) at a buffet lunch 1 hour after preload2. Cumulative energy intake (kJ) over a 24 hour period after

preload

Results

Energy intake (kJ) at a buffet lunch 1 hour after preload

Cumulative energy intake (kJ) over a 24 hour period after preload

Solid = high energy preload (HEP) Dashed = low energy preload (LEP)

Healthy Men 3 hour exercise vs. resting Significant increase in fasting PP

Male Athletes Marathon running Significant increase in fasting PP

Non-obese Healthy Men and Women

45 min exercise, 30 min after 1780 kJ breakfast vs. resting

Significant increase in postprandial levels of PP

Normal Weight Sedentary Males

10wk exercise program (blood tests were taken before & after, fasting & after 1340 kJ breakfast)

Slight increase in PP fasting levels and postprandial peak

Athletes (Men and Women) Marathon running Significant increases in fasting GLP-1 and PP

Physically Active Normal Weight Men

Cycling until exhaustion Significant increase in fasting CCK levels in relation to fasting (no effect on fasting CCK)

Male Athletes 2 hour treadmill run vs. resting

Significant increase in fasting GLP-1 during exercise, but also during resting

CCK: cholecystokinin; PP: pancreatic polypeptide; GLP-1: glucose like-peptide-1

Conclusions

• Exercise is beneficial both short-term and long-term. – Psychologically and physically

• “The beneficial impact of exercise on the energy balance equation is […] twofold, not only increasing energy expenditure but also modulating energy input.”

• This statement is important in encouraging people to become physically active long-term

• Further research can go more in depth and examine if certain types of exercises have more/ less of an effect

• Interesting, but still curious about details.