Nutrition: Chapter 9 - Energy, Weight, & Fitness (Exam 3)

What are the two major energy pathways used by the body?

Anaerobic (glycolysis) and aerobic (TCA cycle + oxidative phosphorylation).

What is ATP?

Adenosine triphosphate—fuel for all energy-requiring processes in the body.

How many kcal per gram do carbohydrates, protein, and fat provide?

Carbohydrate: 4 kcal/g; Protein: 4 kcal/g; Fa:t 9 kcal/g.

What happens during glycolysis?

Glucose → pyruvic acid + ATP; anaerobic; limited exertion; pyruvic acid converts to lactic acid if no oxygen.

What type of exercise relies mainly on glycolysis?

Sprint or speed-type exercise.

What is the primary energy source for exercises lasting at least 5 minutes at low intensity?

TCA cycle (aerobic pathway).

What is oxidative phosphorylation?

Electron transport system reactions that form ATP and water.

How is fat used for energy?

Fat is hydrolyzed → glycerol + fatty acids; glycerol becomes pyruvic acid; fatty acids undergo beta-oxidation → acetyl-CoA → TCA cycle.

How does protein provide energy?

Amino acids undergo deamination and enter as pyruvate or TCA intermediates.

What does the body prefer to spare protein for?

Building and repairing tissues/cells.

What influences how much energy the body uses during exercise?

Intensity, length of exercise, fitness level, and food intake.

What factors influence glycogen storage?

Carbohydrate intake, fitness level, and endurance training.

What are the three major components of daily energy expenditure?

Basal metabolism (BMR), physical activity, and thermic effect of food.

What is basal metabolic rate (BMR)?

Energy needed to maintain life systems (breathing, circulation, heartbeat, hormone secretion).

What affects BMR?

Age, body size, sex, temperature, fasting/starvation, stress, menstruation, thyroid function, lean body mass.

What is resting energy expenditure (REE)?

Practical measurement of energy needs at rest.

What is the thermic effect of food?

Energy to digest, absorb, metabolize, and store food—the smallest contributor to energy expenditure.

What is adaptive thermogenesis?

Energy used to adjust to temperature, trauma, or environmental changes.

Define "healthy weight" from Chapter 9.

Weight that allows comfortable movement, is maintained without extreme restriction or exercise, and carries no weight-related disorders.

What is "healthier weight" according to health promotion programs?

Weight loss of 4-7% of body weight with healthy lifestyle behaviors.

What is the most accurate measure of body fat?

Underwater weighing (densitometry).

What are other methods to measure body fat?

BIA, skinfold thickness, and upper arm circumference.

What limits BMI's usefulness?

It assesses weight, not body fat; it can be inaccurate for the elderly, athletes, and fluid shifts.

Healthy body fat percentage ranges?

Men: 15-20%; Women: 25-30%.

Low body fat may result in what issues?

Amenorrhea, bone loss, and fracture risk.

What is Android (Apple) fat distribution?

Upper-body fat; higher chronic disease risk; WC >40 in men, >35 in women.

What is gynoid (pear) fat distribution?

Lower-body fat.

What is hypertrophy vs. hyperplasia of adipocytes?

Hypertrophy = cells get bigger; Hyperplasia = number of fat cells increases.

When does adipocyte hyperplasia mainly occur?

Infancy, preschool years, adolescence, and pregnancy.

What is the wellness approach to weight?

Long-term changes, realistic goals, behavior change, normalized eating, and active lifestyle.

Key components of physical fitness?

Flexibility, muscular strength/endurance, and cardiovascular endurance.

Cardiovascular endurance depends on what?

The ability to take in, deliver, and use oxygen for physical work.

Health benefits of regular exercise?

Improves CV fitness, decreases BP, helps with weight, decreases risk of several diseases, improves mood, and sleep.

Recommended macronutrient distribution for athletes?

45-65% CHO, 20-35% fat, 10-35% protein.

What is the most critical nutrient for athletic performance?

Water.

What happens when 2-3% body weight is lost from sweating?

Impaired ability, confusion, loss of coordination.

When are sports drinks beneficial?

Activity >90 minutes at moderate/heavy intensity (for CHO, Na, K replacement).

What is carbohydrate loading?

Increasing CHO intake and adjusting training to boost muscle glycogen stores for activity lasting 90+ minutes.

Possible side effects of CHO loading?

Water retention, weight gain, stiffness, cramping, and digestive issues.

Protein requirements for athletes?

1.5-2 g/kg body weight.

Do high-protein diets improve athletic ability?

No evidence supports this.

What truly increases muscle mass?

Resistance training + adequate complex carbohydrate intake.

Recommended fat intake for athletes?

20-25% of total energy.

Do extra vitamins/minerals improve performance?

No—excess may cause toxicity.

What are ergogenic aids?

Products intended to improve strength, power, or endurance—most are not proven effective (except some evidence for creatine).

What is the nurse's role regarding weight and fitness?

Maintain awareness of own attitudes, stay knowledgeable, support client education, and promote realistic lifestyle changes.