Nutrition Lecture 1

Introduction to Nutrition

• Nutrition is a biochemical and physiological process using food to support life, including consumption, digestion, absorption, metabolism, and excretion.

Key Influences on Nutrition

• Cultural Influences: Traditions, values, and beliefs influence food choices, preparation, and consumption.
• Economic Factors: Socioeconomic status impacts access to healthy foods and essential nutrients.
• Pleasure and Emotion: Psychological and emotional factors drive food choices (pleasure, comfort, social bonds).
• Nutritional Requirements: Balanced food types, quantities, and combinations are crucial for body needs.
• Social and Family Dynamics: Social networks, family roles, and peer influence affect eating habits and preferences.
• Cultural/Religious Practices: Religious and ethical restrictions guide acceptable food choices in communities.
• Food Preferences: Taste preferences influence food choices.
• Psychosocial Factors: Emotions, stress levels, and mental health conditions affect eating.
• Chronic Disease Management: Diet management is key to preventing and managing chronic diseases.
• Developmental Needs: Nutritional requirements change throughout a lifespan (infancy to old age).

Roles of Nurses in Nutrition Care

• Nutritional Screening: Identifying patients at risk during hospital admission or routine care.
• Healthcare Provider Liaison: Acting as a bridge between dietitians, physicians, and other healthcare professionals.
• Nutrition Resource: Providing nutritional guidance when dietitians are unavailable.
• Nutrition Counseling Reinforcement: Supporting and reinforcing dietary advice from dietitians.
• Discharge Instructions: Providing dietary recommendations for continued care at home.
• Home Care Nutrition Support: Assisting with nutritional care for homebound patients in collaboration with dietitians.
• Monitoring and Documentation: Tracking nutritional progress and reporting concerns.

Important Nutritional Definitions

• Food: Nutritious substances consumed for life maintenance and growth.
• Nutrient: Compounds in food needed for energy, chemical reactions, and bodily health.
• Macronutrients: Nutrients needed in large amounts (grams) providing energy and structure (carbohydrates, proteins, fats).
• Micronutrients: Nutrients needed in smaller amounts (milligrams or micrograms), like vitamins and minerals, for biochemical processes.
• Vitamin: Organic compounds crucial for metabolic processes, immunity, and health (fat-soluble or water-soluble).
• Mineral: Inorganic elements vital for physiological functions (bone formation, nerve transmission, enzyme reactions).

Nutrient Recap: The 7 Essential Nutrients

1. Carbohydrates

• Definition: Organic compounds (C, H, O) in a 1:2:1 ratio, the body's primary energy source.
• Functions: Energy production, storage, protein sparing, reducing ketosis, supporting GI health.
• Sources: Grains, fruits, vegetables, dairy, sugars.

2. Proteins

• Definition: Major structural and functional body components (amino acids).
• Functions: Body structure, enzyme function, hormone/antibody production, fluid balance, acid-base balance, and energy source.
• Sources: Complete (animal products, soy) and incomplete (legumes, nuts) proteins.

3. Lipids (Fats)

• Definition: Organic compounds (insoluble in water), including triglycerides, phospholipids, and sterols.
• Types: Unsaturated (good), saturated and trans (bad) fats.
• Functions: Energy source, insulation/protection, vitamin absorption, cell structure.
• Sources: Animal fats, plant oils, nuts, seeds.

4. Vitamins

• Definition: Organic substances crucial for regulating body functions and metabolic reactions.
• Categories: Fat-soluble (A, D, E, K) and water-soluble (B vitamins, Vitamin C).
• Functions: Coenzymes, antioxidants, therapeutic uses.

5. Minerals

• Definition: Inorganic elements needed for various physiological functions.
• Categories: Major (needed in larger amounts) and trace minerals (needed in smaller amounts).
• Functions: Support bone health, muscle function, nerve transmission, and enzyme activation.

6. Fiber

• Definition: Indigestible plant components supporting digestive health.
• Types: Soluble (slows digestion, reduces cholesterol) and insoluble (increases stool bulk, prevents constipation).
• Sources: Fruits, vegetables, whole grains, legumes, nuts, seeds.

7. Water

• Definition: Essential for life, acting as a solvent and medium for biological processes.
• Functions: Cell structure, temperature regulation, nutrient transport, lubrication.
• Recommended Intake: Different for men (3.7 liters) and women (2.7 liters) per day.

Food Group Theories

• Classifying foods into groups simplifies nutritional planning and promotes balanced diets.

Food Group Classifications

• Staples: Cereals, starchy fruits, roots, and tubers (carbohydrates, vitamins, minerals, fiber)
• Legumes and Nuts: Peas, beans, nuts (protein, carbohydrates, calcium, iron, fiber)
• Vegetables: Dark leafy greens, yellow vegetables (vitamins, minerals, fiber)
• Fruits: Mangoes, guavas, oranges, etc. (carbohydrates, vitamins, minerals, fiber)
• Foods from Animals: Meat, fish, poultry, eggs, dairy, organ meats (protein, iron, B vitamins, fat-soluble vitamins, fat)
• Fats and Oils: Vegetable oils, butter, margarine, coconut oil (fats, vitamin E, A, D)

Multimix Principle

• Combining food groups maximizes nutritional value, particularly in regions with limited dietary variety.

Types of Multimix Combinations

• Double Mix: Combining two food groups (Rice and peas, toast and baked beans, macaroni and cheese)
• Triple Mix: Combining three food groups (Rice, peas, and carrots, ripe plantain, saltfish and callaloo.)
• Quadri-Mix: Combining four food groups (Boiled dumplings, stewed beef, broad beans, and carrots)

Food Composition Tables (FCT)

• Food Composition Tables/Databases provide detailed nutritional information (macronutrients, micronutrients, calories).
• Sources include the Pan-American Health Organization, FAO, European & Asian Food Databases.

Recipe Calculations

• Essential for assessing composite dish nutritional value.

Why Use Recipe Calculations?

• Food composition: Accurate and consistent nutritional assessment for recipes.
• Food consumption surveys: Crucial for nationwide/regional nutrient intake assessment.
• Diet counseling: Allows for personalized dietary plans.
• Food labels: Used by the food industry.

Steps in Recipe Calculations

• Identify ingredients, weights, and preparation methods.
• Apply factors (yield factor, edible coefficient, retention factor).
• Calculate accurate nutritional values using the mixed method.
• Document all data clearly.

Recipe Calculation Methods

• Summing of Raw Ingredients - Underestimates values due to cooking losses
• Ingredient Method - Calculates each ingredient's contribution with factors; no recipe categorization.
• Total Recipe Method - Weights the final cooked product using factors; extensive measurements.
• Mixed Method - Combines yield and retention factors at both ingredient and recipe levels for accuracy (preferred).

Common Errors in Recipe Calculations

• Forgetting cooking aids (water, fat).
• Skipping edible coefficients.
• Incorrect factor application.
• Missing/incorrect nutrient values.
• Introducing zero values where data is unavailable.

Nutrient Recap: Detailed Explanations of Key Nutrients

Carbohydrates

• Definition: Organic compounds (C, H, O) in a 1:2:1 ratio. Main energy source.
• Functions: Energy production/storage, protein sparing, reducing ketosis, GI health.
• Types: Simple (sugars), Complex (starches, fibers)
• Sources: Grains, fruits, vegetables, dairy, sugars.

Proteins

• Definition: Large molecules (amino acids) essential to body structure, reactions, and functions.
• Functions: Structure, enzymes, hormones, immunity, fluid/acid-base balance, transport, energy (when needed).
• Sources: Complete (animal, soy) and incomplete (plant-based) proteins.

Lipids (Fats)

• Definition: Hydrophobic organic compounds. Serve as a concentrated energy source and support essential bodily functions.
• Types: Triglycerides, phospholipids, sterols (cholesterol).
• Functions: Energy storage, insulation/protection, vitamin absorption, cell structure, hormonal regulation.
• Sources: Animal fats, plant oils, nuts, seeds, fish.

Vitamins

• Definition: Organic compounds crucial for regulating body functions and metabolic reactions.
• Categories: Fat-soluble (A, D, E, K) and water-soluble (B vitamins, Vitamin C).
• Functions: Metabolic regulation, antioxidants, therapeutic uses.

Minerals

• Definition: Inorganic elements essential for various physiological functions (bone formation, enzyme activation, nerve transmission).
• Types: Major (Calcium, phosphorus, sodium, potassium) and Trace (Iron, Zinc, copper) minerals.