Nutrients and Energy Balance Quiz

Nutrition: Science of Foods and Nutrients

• Energy and nutrients used by the body for maintenance, growth, and repair
• Nutrients categorized into macronutrients (carbohydrates, lipids, protein) and micronutrients (vitamins, minerals, water)

Macronutrients

• Provide energy for the body
• Carbohydrates: primary fuel source, especially for the brain
• Lipids: energy and essential nutrients
• Protein: tissue growth, repair, and maintenance (can also be used for energy)

Calculating Energy from Food

• 4 kcal/gram of carbohydrates and protein
• 9 kcal/gram of fat
• 7 kcal/gram of alcohol
• Use Atwater values to calculate total kcal

Acceptable Macronutrient Distribution Ranges (AMDR)

• Carbohydrates: 45-65% of daily energy intake
• Lipids: 20-35% of daily energy intake
• Protein: 10-35% of daily energy intake

Importance of Nutrition

• Can prevent some diseases and reduce risk for others
• Importance of nutrition in diseases such as osteoporosis, osteoarthritis, and certain types of cancer
• DRI (Dietary Reference Intakes) for energy, nutrients, and other dietary components that support health

Dietary Reference Intakes (DRI)

• Estimated Average Requirements (EAR) for nutrients
• Recommended Dietary Allowance (RDA) for almost everyone
• Adequate Intake (AI) for nutrients with limited scientific evidence
• Tolerable Upper Intake Level (UL) for nutrients that may have adverse effects at high levels

Energy and Macronutrients

• Estimated Energy Requirement (EER) based on age, gender, weight, height, and physical activity
• Acceptable Macronutrient Distribution Ranges (AMDR) for carbohydrates, lipids, and protein

Dietary Ideals

• A nutritious diet should be adequate, moderate, balanced, varied, and nutrient-dense
• Eating a variety of foods from different food groups is essential for good health

Food Labels and Nutrition

• Food labels provide information on %DV (percent of the Daily Value) for nutrients
• %DV is based on a 2,000 kcal diet
• Compare %DV between food items to make informed choices

Nutrient and Health Claims

• Nutrient claims describe the nutrient content of a product
• Health claims describe the potential health benefits of a food

Hunger and Satiety

• Hunger is a physiological need to eat, while appetite is a psychological desire to eat
• Satiety is the feeling of fullness and satisfaction
• Regulated by the brain, signals, and hormones

Digestion and Absorption

• Digestion: breaking down nutrients into smaller units
• Absorption: moving nutrients across the digestive system into the bloodstream or lymph system
• Elimination: removing undigested or unabsorbed products from the body

Regulation of GI Activity

• CNS, PNS, and hormones regulate GI activity
• Gastrin, secretin, and GIP hormones play important roles in regulating digestion

Carbohydrates

• Simple carbohydrates (monosaccharides): glucose, fructose, galactose
• Complex carbohydrates (oligosaccharides and polysaccharides): starch, glycogen, fiber
• Carbohydrates spare proteins by preventing their breakdown as an energy source### Nutrition Basics
• AAMDR (Acceptable Macronutrient Distribution Range) for adults: 10-35% of daily caloric intake from protein
• RDA (Recommended Dietary Allowance) for protein depends on age, activity, health status, and body weight
• Infants, adolescents, pregnant/lactating women, vegetarians, and athletes have different protein requirements

Vitamins

• Organic compounds essential to an organism in small amounts for metabolic processes
• Contribute no energy to the body (non-kcaloric)
• Deficiencies in vitamins can cause various health problems (e.g., blindness, dementia, retarded bone growth)
• Bioavailability: how much of a nutrient can be used for function
• Factors influencing vitamin bioavailability: efficiency of digestion, previous intake and status, preparation, source of nutrient
• Precursors (provitamins) are inactive forms available in food, converted to active forms inside the body
• Solubility: fat-soluble (Vitamins A, D, E, K) and water-soluble (B vitamins and Vitamin C)

Minerals

• Indestructible, inorganic compounds essential to the body
• Various roles: influence fluid balance, nerve transmissions, muscle contractions, energy metabolism, and bone structure
• Major minerals: calcium, chloride, magnesium, phosphorus, potassium, sodium, and sulfur
• Trace minerals: chromium, copper, fluoride, iodine, iron, manganese, molybdenum, selenium, and zinc

Water and Energy Metabolism

• Water: highly essential (60% of human body), with various roles (cushion, transport, medium for processes)
• Energy metabolism: sum of all chemical reactions in living cells, required to provide energy to the cells
• Principal organs involved in energy metabolism: digestive, liver, pancreas, heart, blood vessels, and kidneys
• Metabolic work: heat, body temperature, and accelerated metabolism
• ATP (adenosine triphosphate): high-energy molecule, transfers energy in small usable amounts
• ATP synthesis: requires energy, ATP breakdown: releases energy
• Glycolysis: extracts energy from glucose, pyruvate, and acetyl-CoA
• TCA Cycle (Krebs Cycle): releases energy through oxidation of acetyl-CoA
• ETC (Electron Transport Chain): final step in energy metabolism, produces ATP molecules

Oxidative Protection

• Free radicals: unstable molecules that can cause cell damage and cell death
• Antioxidants: substances in foods that significantly decrease the adverse effects of reactive species
• Vitamins E, C, and A: donate electrons to stabilize free radicals
• Minerals: zinc and copper act as cofactors to enzymes that convert free radicals to less damaging substances

Body Fluid and Electrolyte Balance

• Body fluid: approximately 36kg of water, divided into ICF (intracellular fluid) and ECF (extracellular fluid)
• Electrolytes: sodium, potassium, magnesium, calcium, and chloride
• Water homeostasis: need to control total body water and water location
• Sources of water: metabolic reactions, diet, and environmental influences
• Average water intake: 1450-2800 mL/day
• Health Canada's recommended water intake: dependent on diet, activity, environment, and body size

Blood Health

• Iron: essential for hemoglobin production, interacts with platelet clotting, and cofactor for enzymes
• Vitamin K: essential for blood clotting, bone health, and energy metabolism
• Folate and Vitamin B12: essential for protein metabolism, DNA synthesis, and RBC production
• Copper: essential for hemoglobin synthesis, energy metabolism, and immune function

Bone Health

• Bone anatomy: cortical (compact) and trabecular (sponge-like) bone
• Bone functions: structure, support, and metabolic processes
• Calcium: essential for bone health, 99% stored in bones and teeth
• Vitamin D: essential for bone growth, maintains blood calcium and phosphorus levels
• Vitamin K: essential for bone formation, synthesizes osteocalcin
• Phosphorus: essential for bone structure, energy metabolism, and genetic material
• Magnesium: essential for bone structure, energy metabolism, and membrane transport
• Fluoride: essential for bone health, strengthens bones and teeth

Energy Balance and Body Composition

• Energy balance: maintains healthy weight over time, balance between energy intake and expenditure
• BMR (Basal Metabolic Rate): rate at which person expends energy at rest
• RMR (Resting Metabolic Rate): measure of energy use at rest, above basal metabolism
• Physical activity: voluntary movement of skeletal muscles, above basal metabolism
• Thermic effect of food: energy required to process food
• Imbalance: under, over, or obesity

Body Composition

• Body weight: BMI (weight kg/height m2), normal range 18.5-24.9
• Body composition: lean body mass and percent body fat
• Ideal amount of body fat: enough to meet basic needs (13-21% for men, 23-31% for women)
• Genetic factors: thrifty gene theory, set-point theory
• Physiological factors: hunger and satiety, proteins and hormones (leptin, grehlin)

Physical Activity

• FIT principle: frequency, intensity, time, and type
• Fuel for physical activity: ATP, creatine phosphate, carbohydrates, lipids, and proteins
• Physiological responses: increase in energy expenditure, heart rate, and breathing rate

Nutrition for Pregnancy and Lactation

• Nutrition in stages: crucial during pregnancy and infancy
• Prior to pregnancy: full nutrient stores, healthy body weight, and healthy support tissues
• During pregnancy: critical periods and nutrition, folate and iron, and developmental changes
• After pregnancy: mother's nutrition, lactation, and infant's nutrition
• Infancy, childhood, adulthood, and elderly/aging: distinct nutritional needs and challenges