Final

Chapter 8: Nutrients Essential to Key Body Functions

B Vitamins and Their Functions

B vitamins play crucial roles as coenzymes in metabolic processes, supporting energy production and the synthesis of key biomolecules.

• Thiamin (B1): Supports carbohydrate and amino acid metabolism. Deficiency leads to beriberi, characterized by muscle wasting and nerve damage.

• Riboflavin (B2): Important for carbohydrate and fat metabolism. Forms FAD.

• Niacin (B3): Required for carbohydrate and fat metabolism. Forms NAD and NADP. Deficiency causes Pellagra (dermatitis, diarrhea, dementia).

• Pyridoxine (B6): Amino acid metabolism, neurotransmitter synthesis.

• Folate: DNA synthesis, cell division, and amino acid metabolism. Deficiency leads to neural tube defects.

• Cobalamin (B12): Assists with formation of red blood cells and DNA synthesis. Deficiency can cause anemia and neurological issues.

Oxidation and Reduction

Oxidation and reduction reactions are essential for energy metabolism and cellular defense against free radicals.

• Oxidation: Loss of electrons. $\text{Reactant} \rightarrow \text{Product} + e^-$

• Reduction: Gain of electrons. $\text{Reactant} + e^- \rightarrow \text{Product}$

Antioxidants and Cancer Prevention

Antioxidants such as vitamins C, E, and carotenoids protect cells from oxidative damage and may reduce cancer risk.

• Vitamin C: Synthesis of collagen, enhances iron absorption, supports immune function.

• Vitamin E: Protects cell membranes from free radicals.

• Carotenoids: Enhance immune system, protect eyes and skin.

Vitamin Deficiencies and Toxicities

• Niacin toxicity: Flushing, tingling, liver damage.

• Folate deficiency: Neural tube defects in infants.

• Iodine deficiency: Goiter, hypothyroidism, and cretinism.

Sources of Key Nutrients

• Iodine: Iodized salt, dairy.

• Vitamin E: Vegetable oils, nuts/seeds, leafy greens.

• Vitamin C: Bell peppers, citrus fruits, strawberries.

Carcinogens and Cancer Risk Factors

• Modifiable risk factors: Tobacco, alcohol, obesity, poor nutrition, physical inactivity, UV radiation.

• Prevention steps:

  1. Regular screening

  2. Avoid tobacco/alcohol

  3. Physical activity

  4. Healthful weight and diet

Chapter 9: Nutrients Essential to Healthy Tissues

Iron: Functions, Requirements, and Absorption

Iron is a major component of hemoglobin and myoglobin, essential for oxygen transport in blood and muscles.

• Daily requirements:

  • Men: 8 mg

  • Women: 18 mg

  • Pregnant women: 27 mg

• Factors influencing absorption: Heme iron (animal products) is absorbed better than non-heme iron (plant products). Vitamin C enhances absorption.

• Toxicity: Overconsumption can cause organ damage.

Vitamin C: Role and Sources

• Function: Produces and maintains healthy collagen.

• Recommended intake: 90 mg/day for men, 75 mg/day for women.

• Sources: Bell peppers, citrus fruits, strawberries.

Bone Health: Calcium and Vitamin D

• Bone modeling: Shape and size change after puberty.

• Bone remodeling: Breakdown and formation throughout life.

• Peak bone density: Achieved by late 20s.

• Calcium functions:

  • Forms and maintains bones and teeth

  • Acid-base balance

  • Nerve impulse transmission

  • Muscle contraction

• Recommended intake: Adults: 1,000 mg/day; Older adults: 1,200 mg/day

• Vitamin D: Enhances calcium absorption, regulates bone growth.

Osteoporosis: Risk Factors and Prevention

• Risk factors: Age, gender, genetics, low calcium/vitamin D intake, inactivity.

• Prevention: Adequate calcium/vitamin D, weight-bearing exercise.

Chapter 10: Achieving and Maintaining a Healthful Body Weight

Components of a Healthful Body Weight

A healthful body weight is appropriate for age, maintained without constant dieting, and promotes good health.

• Key components: Normal blood pressure, lipid levels, glucose tolerance, family history, and absence of eating disorders.

Body Mass Index (BMI)

• Calculation: $\text{BMI} = \frac{\text{weight (kg)}}{\text{height (m)}^2}$

• Limitations: Does not account for muscle mass or body composition.

Fat Distribution Patterns

• Apple-shaped: Increased risk of chronic disease.

• Pear-shaped: Lower risk.

Energy Balance Equation

• $\text{Energy Expenditure} = \text{Energy Intake} - \text{Energy Output}$

• Physical activity: Accounts for 15-15% of daily energy expenditure.

Obesity and Metabolic Syndrome

• Obesity: BMI > 30 kg/m2

• Metabolic syndrome: Cluster of biochemical and physiological abnormalities increasing risk of cardiovascular disease and type 2 diabetes.

Chapter 11: Nutrition and Physical Fitness

Benefits of Physical Activity

Regular physical activity improves heart and lung health, strengthens muscles and bones, lowers risk of chronic diseases, and helps maintain a healthy weight.

• Improved heart and lung health

• Stronger muscles and bones

• Lower risk of chronic diseases

• Helps maintain a healthy weight

Types of Physical Activity

• Aerobic: Cardiovascular fitness

• Resistance: Musculoskeletal fitness

• Stretching: Flexibility

Energy Systems in Exercise

• ATP-CP system: Immediate energy for short bursts

• Glycolysis: Anaerobic metabolism for moderate duration

• Aerobic metabolism: Long duration, uses carbohydrates and fats

Nutrition for Athletes

• Carbohydrate loading: Endurance athletes benefit from increased carbohydrate intake before events.

• Hydration: Athletes should drink 1 cup of fluid every 15 minutes during exercise.

Eating Disorders in Athletes

• Anorexia nervosa: Severe calorie restriction

• Bulimia nervosa: Binge eating and purging

• Binge eating disorder: Recurrent episodes of binge eating

• Female athlete triad: Disordered eating, amenorrhea, osteoporosis

Chapter 12: Food Safety and Technology

Foodborne Illnesses and Prevention

Food safety is essential to prevent foodborne illnesses caused by bacteria, viruses, fungi, and parasites.

• Agencies: USDA, CDC, FDA, EPA

• Common pathogens: Salmonella, Listeria, E. coli

• Prevention: Clean, separate, cook, chill

• Danger zone: 40°F–140°F (temperature range for bacterial growth)

Genetic Modification

• Steps: Identify trait, isolate gene, insert gene, grow and select modified organism, regulatory approval

• Benefits: Improved crop yield, pest resistance, enhanced nutrition

• Risks: Environmental impact, allergenicity, ethical concerns

Chapter 13: Food Equity, Sustainability, and Quality

Food Insecurity and Global Hunger

Food insecurity affects millions globally, with poverty and climate change as major contributors.

• Food insecurity: 17.4 million U.S. households (2011)

• Undernutrition: Sub-Saharan Africa has highest prevalence

• Causes: Poverty, climate change, lack of infrastructure

Sustainable Agriculture

• Practices: Crop rotation, organic farming, recycling resources

• Food diversity: Promotes resilience and nutrition

Food Deserts

• Definition: Areas with limited access to affordable, nutritious food

Chapter 14: Nutrition Through the Life Cycle: Pregnancy and the First Year of Life

Pregnancy: Nutrition and Health

Proper nutrition during pregnancy is essential for maternal and fetal health, reducing risks of gestational diabetes, preeclampsia, and birth defects.

• Gestational diabetes: Reduced risk with exercise and healthful diet

• Trimesters:

  • First: Weeks 1–13

  • Second: Weeks 14–27

  • Third: Weeks 28–40

• Birth weight: Average full-term infant is 7.5 pounds, 20 inches

• Risks: High blood pressure, preeclampsia, preterm birth

Nutrition-Related Concerns During Pregnancy

• Morning sickness

• Constipation

• GERD

• Gestational diabetes

• Gestational hypertension

Recommendations for Exercise and Alcohol Use

• At least 150 minutes of moderate exercise per week

• Alcohol risks: Fetal alcohol syndrome, birth defects, developmental delays

Lactation and Infant Nutrition

• Calories required: 700–800 kcal/day for milk production

• Exclusive breastfeeding: Recommended for first 6 months

• Common allergens: Milk, eggs, peanuts, soy, shellfish, wheat