Nutrition and Exercise Physiology Quiz

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Questions and Answers

What is the primary role of ghrelin in the regulation of eating behavior?

Regulates blood glucose

Inhibits appetite

Stimulates appetite (correct)

Terminates meals

What defines obesity in terms of body composition?

Balanced energy intake and expenditure

Excessive fat content (correct)

High muscle mass

Low energy storage in adipose tissue

Which energy system is primarily used during short-term, high-intensity exercise?

Glycolytic system

Fat oxidation

Aerobic system

Phosphagen system (correct)

What cardiovascular change remains unchanged during exercise?

Blood flow to the brain Signup and view all the answers

Which of the following is a source of ATP during muscle contraction?

Phosphocreatine Signup and view all the answers

During long-term, moderate-intensity exercise, which contribution to ATP production is greater?

Aerobic contribution Signup and view all the answers

What primarily categorizes BMR?

Energy expenditure per unit of time at rest Signup and view all the answers

Which factor is LEAST likely to affect an individual's BMR?

Body temperature Signup and view all the answers

How is energy output primarily categorized?

External and internal work Signup and view all the answers

What does the first law of thermodynamics assert regarding energy?

Energy cannot be created or destroyed Signup and view all the answers

What percentage of the chemical energy in food is typically harnessed for biological work?

25% Signup and view all the answers

Which category falls under internal work regarding energy output?

Digestion and cellular processes Signup and view all the answers

Obesity can be understood as an imbalance in which aspect?

Energy input-output balance Signup and view all the answers

What is primarily transformed from unused energetic nutrients?

Thermal energy or heat Signup and view all the answers

What is essential for regulating food intake in relation to energy balance?

Hormonal signals and feedback mechanisms Signup and view all the answers

What conditions should be met for measuring basal metabolic rate (BMR)?

Mental and physical rest Signup and view all the answers

Which factor is NOT known to affect basal metabolic rate (BMR)?

Immune system strength Signup and view all the answers

How is energy balance categorized when energy input exceeds energy output?

Positive energy balance Signup and view all the answers

Which hormone is primarily responsible for increasing appetite?

Neuropeptide Y Signup and view all the answers

What effect does high leptin have on appetite control?

Decreases appetite by inhibiting NPY Signup and view all the answers

Which process is primarily measured by indirect calorimetry?

Oxygen uptake Signup and view all the answers

What is the role of insulin in appetite regulation?

Decreases appetite by inhibiting NPY Signup and view all the answers

Which of the following describes short-term regulation of food intake?

Size and frequency of meals Signup and view all the answers

What occurs when leptin levels are low?

Food intake increases Signup and view all the answers

Which statement about direct calorimetry is true?

It assesses heat production from metabolic activity. Signup and view all the answers

Study Notes

Basal Metabolic Rate (BMR) and Obesity

BMR is the energy expenditure per unit of time by the body during both external and internal work.
It's measured in kilocalories of heat produced per hour.
It's the metabolic activity necessary to maintain basic body functions at rest.

Energy Balance

Energy cannot be created or destroyed (first law of thermodynamics).
Energy input comes from ingested food.
Energy output includes external work (moving objects or body) and internal work (biological energy not accomplishing external mechanical work).

Energy Conversion

Only about 25% of chemical energy in food is used for biological work, 75% is converted to heat to maintain body temperature.
The rest of food energy is transformed into thermal energy or heat.

Measurement of BMR

Direct calorimetry measures heat produced by the body.
Indirect calorimetry measures oxygen uptake to estimate metabolic rate.
Measurements should be taken during physical rest, mental rest, room temperature, and after 12 hours without food.

Factors Affecting BMR

Gender
Smoking
Exercise
Food intake
Hormones
Pregnancy
Age
Temperature
Sleep

Obesity

Excessive fat content in adipose tissue stores.
Body Mass Index (BMI) is used to classify weight status.
BMI is calculated as weight (kg) / height (meters)^2.
- Underweight: < 18.5
- Normal: 18.5-24.9
- Overweight: 25-29.9
- Obese: > 30

Regulation of Food Intake

Short-term regulation controls meal size and frequency.
Long-term regulation maintains normal energy stores in the body.

Appetite Control at Arcuate Nucleus of Hypothalamus

Neuropeptide Y (NPY) neurons stimulate appetite and increase food intake.
Melanocortin hormone (MSH) neurons decrease appetite and decrease food intake.

Long-Term Maintenance of Energy Balance

Leptin, secreted from adipocytes, is proportional to fat stores.
- High leptin suppresses appetite.
- Low leptin increases appetite.
Insulin, secreted from the pancreas, is released in response to high blood glucose (hyperglycemia).
- High insulin suppresses appetite.

Short-Term Regulation of Eating Behavior

Ghrelin, secreted by the stomach, is known as the "hunger hormone" and stimulates appetite.
- It starts a meal.
Peptide YY (PYY), secreted by the small and large intestine, suppresses appetite and terminates a meal.

Energy Systems for Exercise

Immediate: Phosphocreatine and ATP (used in <10 seconds)
Short term: Glycolytic (glycogen-lactic acid, used in 1-2 minutes)
Long term: Aerobic (used for longer durations)
The type of exercise and duration determines which energy system is primary.

Interaction between the Energy Systems & ATP Production

Both anaerobic and aerobic energy systems work together, with one often dominating depending on the activity and its intensity, but never fully isolated.

Cardiovascular Changes During Exercise

Heart rate, stroke volume, and cardiac output increase.
Blood flow to skeletal muscles increases.
Blood flow to other organs may decrease.
Blood flow to the brain remains relatively unchanged.

Why Diabetic Patients are Recommended to Exercise Frequently

Exercise can reduce plasma hyperglycemia by increasing glucose uptake in active muscles, independent of insulin.

Result of Positive Energy Balance and Dysregulation of GI Hormones

Positive energy balance and GI hormone dysregulation may lead to obesity and related health issues.

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Description

Test your knowledge on key concepts in nutrition and exercise physiology. This quiz covers topics such as energy systems, body composition, metabolic rate, and the regulation of eating behavior. Perfect for students exploring the intersection of nutrition and physical performance.