Complete Nutrition Science: Macronutrients & OmpathStudy

COMPLETE NUTRITION REVISION NOTES (Compiled: Macronutrients + Micronutrients + BND 3104 Notes —) --- PART 1: FOUNDATIONS 1.1 Key Definitions Term Definition --- --- Nutrition Science of food & its relationship to health; ingestion→digestion→absorption→assimilation for growth/repair/maintenance Health (WHO) Complete physical, mental, social wellbeing — not just absence of disease Food Any nutritious substance ingested to sustain life/growth Nutrients Chemical substances in food needed for growth, maintenance, repair (~50 known) Diet What a person habitually eats/drinks Digestion Mechanical + chemical breakdown of food Malnutrition Imbalance from deficiency/excess/faulty utilization of nutrients Nutritional status Current body state re: nutrient consumption/utilization Functional foods Foods with added health benefits beyond normal nutrition Disease Abnormal condition — Signs (observable e.g. swelling) vs Symptoms (felt e.g. nausea) 1.2 Disease Prevention Levels 1. Primary — averting disease occurrence 2. Secondary — early screening (e.g. diabetes screening) 3. Tertiary — treatment post-diagnosis to prevent complications 1.3 Core Principles of Nutrition Science Food = basic human need (Maslow's hierarchy) Health problems originate at cellular level Poor nutrition = both inadequate AND excessive intake Body has adaptive mechanisms (storage/elimination) — but limited protection Nutrigenomics = study of nutrient-gene interactions Vulnerable groups need higher nutrient intake (pregnant/lactating, infants, ill, elderly) Healthy diet = Adequacy + Variety + Balance No food is inherently "good" or "bad" 70% of disease is preventable through good nutrition 1.4 Classification of Nutrients Basis Categories --- --- Chemical nature Carbs, Proteins, Fats, Minerals, Vitamins, Fibre, Water Function Energy-giving (CHO/fat/protein) / Body-building (protein/fat/CHO) / Protective-regulators (vitamins/minerals) Chemical property Organic (carbon-containing) vs Inorganic Essentiality Essential (diet-required) vs Non-essential (body-synthesized) Mass Macronutrients (large amounts) vs Micronutrients (small amounts) Origin Animal-source vs Plant-source --- PART 2: MACRONUTRIENTS 2.1 Carbohydrates Definition: Organic compounds (C,H,O) — main energy source; 4 kcal/g Types: Simple: Monosaccharides (glucose, fructose, galactose) + Disaccharides (maltose, lactose, sucrose) Complex: Starch, Glycogen (body's storage form — liver & muscle), Fibre Fibre: Soluble (oats, beans, citrus — ↓cholesterol, regulates blood sugar) vs Insoluble (wheat bran, fruit/veg skins — bowel regularity, ↓cancer risk) Functions: Energy/fuel, spares protein, prevents ketosis, aids Ca absorption (lactose), faecal bulk RDA: 45–65% total calories; minimum 130g/day Deficiency: Hypoglycemia, ketosis→ketoacidosis, impaired cognition, constipation, muscle breakdown Excess: Obesity, insulin resistance/T2DM, cardiovascular disease 2.2 Proteins Definition: Amino acid chains (C,H,O, N ) — tissue building blocks; 4 kcal/g Amino acids: Essential (9): Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan, Valine Non-essential: Body-synthesized (Alanine, Glutamic acid, Serine, etc.) Conditionally essential (illness/stress): Arginine, Cysteine, Glutamine, Tyrosine, Glycine Types: Complete (all essential AAs — meat, dairy, eggs, soy) Incomplete (missing AAs — beans, nuts; limiting amino acid = cereals→lysine, legumes→methionine/cysteine) Functions: Repair/growth, enzymes (trypsin, pepsin), hormones (insulin), antibodies, transport (haemoglobin), backup energy RDA: 10–35% total calories; Men 56g/d, Women 46g/d, Pregnant 71g/d Deficiency: Muscle wasting, oedema, weak immunity, growth retardation Excess: Kidney strain, ↑CVD risk 2.3 Fats/Lipids Definition: Fatty acids + glycerol; 9 kcal/g (most energy-dense) 3 main types: Triacylglycerols ( 95% dietary fat) — fried foods, oils, butter Phospholipids (~2%) — build cell membranes, water-soluble Sterols (e.g. cholesterol) — cell membranes, hormone/vitD/bile salt precursor Fatty acid types: Saturated (no double bonds, solid) Monounsaturated (1 double bond — olive oil) Polyunsaturated (2+ double bonds — soybean oil) Cis (natural) vs Trans (hydrogenated, harmful) Essential fatty acids: Omega-3 (alpha-linolenic — flaxseed, fish) & Omega-6 (linoleic — corn, sunflower oil) Functions: Energy, cell structure, absorbs vitamins A/D/E/K, hormone precursor, insulation, organ padding, satiety RDA: 20–35% total calories; saturated fat <10%, trans fat <1% Deficiency: Dry skin, hormonal imbalance, impaired brain function Excess: Obesity, ↑cholesterol/CVD, insulin resistance 2.4 Metabolism Catabolism = breakdown → releases energy (ATP) Anabolism = synthesis → uses energy Importance: Energy production, growth/repair, homeostasis, waste elimination Factors affecting rate: Age(↓), muscle mass(↑rate), genetics, diet, hormones (thyroid), cold temp(↑rate) Pathways: Carbs: Glycolysis (glucose→2 pyruvate, 2 ATP) → Krebs cycle (Ace