Introduction to Nutrition

Course Objectives

• The course covers nutritional terminology.
• The course encompasses carbohydrates, energy, metabolism, and thermogenesis.
• It includes protein digestion and the role of amino acids for general health and growth.
• Addresses nitrogen balance and protein quality.
• The role of fat digestion, fatty acids absorption, and function, including lipoproteins are included.
• Elucidates water's functions in food utilization, water balance, and related disorders.
• The study of digestion, absorption, and metabolism is part of the course.

Introduction to Nutrition

• Nutrition is the scientific study of how the body is nourished, going beyond just eating a balanced diet.
• It examines various nutrients, their characteristics, functions, requirements, and sources.
• It also covers the effects of nutrient deficiency, excessive intake, digestion, absorption, and utilization.
• Understanding the interrelationships among nutrients is crucial.
• Nutrition involves processes in which the human body receives and uses necessary nutrients for various functions.
• It is also important for growth, components renewal, and utilizing food

Essential Elements of Nutrition

• Consuming appropriate food types and quantities is a key aspect
• Absorption of nutrients into the bloodstream is necessary.
• Using individual nutrients by cells is crucial for the maintenance and growth of cells, tissues, and organs.
• Eliminating waste is also important.

Defining Food and Nutrients

• Food is any substance that nourishes the body and is suitable for consumption, whether solid or liquid.
• Food provides materials for energy, growth, maintenance, and regulation of bodily functions.
• Nutrients are the materials that comprise food.

Key Nutrients

• There are six key nutrients for nutrition: carbohydrates, fats, proteins, vitamins, minerals, and water.
• Different foods have varied amounts of nutrients, so no two foods have the same nutritive value.
• Some foods contain only one nutrient, such as sugar, which mainly contains carbohydrate.

What is a Diet?

• A diet refers to the types and amounts of food and beverages consumed daily.
• It can be a normal diet or a modified one, used to treat a specific disease or condition.

Understanding Nutrients

• Nutrients are chemical substances in food necessary for bodily functions.
• Food serves as the source for all nutrients.
• Six major groups exist: proteins, carbohydrates, fats, vitamins, minerals, and water, each with specific functions.

Macronutrients vs. Micronutrients

• Nutrient classes are categorized as macronutrients, needed in larger amounts, and micronutrients, needed in smaller amounts.
• Macronutrients include carbohydrates, protein, fat, fiber, and water.
• Micronutrients include vitamins and minerals.

Food Groups: Classification and Variety

• Food groups are classified based on their nutrient profiles.
• Common food groups include:
  • High-protein foods like meat, fish, eggs, dairy, and legumes.
  • Carbohydrate-rich foods such as cereals, roots, and tubers.
  • Dairy foods.
  • Fruits and vegetables.
  • Foods rich in fat or oil.
• Foods vary in energy and nutrient content.
• Different foods contain different amounts of nutrients, leading to no two foods having identical nutritive value.

Estimating Nutritional Intake

• Food groups are a source of nutrients.
• A difficult task in nutritional medicine is accurately estimating a patient's nutritional intake and diet.
• This difficulty arises because a person's diet varies daily and food processing affects nutrient content.
• Furthermore, individuals with nutritional problems often struggle to recall what they have eaten accurately.

Dietary Value

• Assessing dietary value involves measuring the energy and nutrient content of a diet, often referencing dietary guidelines.
• Food and diets have various types of value, including political, economic, social, and cultural aspects.

Dietary Reference Values (DRVs): Standards for Nutrient Intake

• DRVs are standards for the amount of each nutrient needed to maintain good health.
• Daily nutrient needs vary among individuals.
• The measured average requirement plus 20% covers the needs of most of people; in the UK, this is termed Reference Nutrient Intake (RNI).
• Alternative names for DRVs include Recommended Daily Allowances or Intakes (RDA or RDI), Population Reference Intake (PRI), and Dietary Reference Intake (DRI).
• The committee on Medical Aspects of Food Policy (COMA) sets reference values for nutrient and energy intakes in the UK.
• DRVs indicate the amount of nutrients needed to maintain health daily.
• They are based on population groups rather than individuals.
• The Reference Nutrient Intake (RNI) represents an intake level exceeding the requirements of 97.5% of the population.
• An individual's intake falls below the RNI will not necessarily cause a deficiency.

DRVs and Individual Needs

• DRVs offer guidelines for daily energy and 33 nutrients.
• The DRVs are:
  • Estimated Average Requirement (EAR): average nutrient or energy needs.
  • Reference Nutrient Intake (RNI): This meets the needs of 97.5% of the population.
  • Lower Reference Intake (LRI): appropriate for only 2.5% of individuals.
  • Safe Intake: an intake range unlikely to cause harm.
• Individual nutritional needs depend on age, sex, body size, activity level, and health status.

Additional DRV Considerations

• There are RDVs that include High Intakes, which indicate upper intake levels with no further benefit and possible harm.
• Desirable intakes of total fat, saturated fats, sugars, and starches are percentages of the EAR for energy.
• Estimates of desirable intakes are based on calories required by sleep or rest plus energy expended by physical activity.
• COMA determined that lower activity requires fewer calories.

Calorie Needs by Age and Sex

• Displayed in a table illustrating varying calorie requirements by age and sex.

Guidelines and Calcium Needs

• The comprehensive report "Dietary Reference Values DRVs for food energy and nutrient for the United Kingdom", presents the standards.
• RNIs are established for vitamins A, B1, B2, B3, C, D, and folate.
• Daily RNIs are also recommended for calcium, iron, phosphorus, magnesium, potassium, and zinc, with a daily amount of 30 mg.
• Calcium needs are considered higher than previously recommended, especially for premenopausal women.

Dietary Recommendations

• Dietitians endorse DRVs within the Health Education Authority report as a basis for average dietary advice
• Dietary Recommendation:
  • Balance energy intake with physical activity.
  • Reduce energy from total fat from 40% to 35%.
  • Lower energy consumption from saturated fats from 17% to 11%.
  • Consumption of non-starch polysaccharides to increase from 12 g to 18 g per day.
  • Reduce sugar by about a quarter.
  • Decreased salt consumption from 10 g (3.2 g sodium) to 4 g (1.6 g sodium) per day.
  • Maintain a varied diet for sufficient mineral and vitamin intake.
  • Increase consumption of fruits and vegetables. -Increase fiber-rich foods such as pasta, rice, and bread.

Health Defined

• Health, according to WHO, is a state of physical, mental, and social well-being, not only the absence of disease.
• It is a positive state of overall well-being, requiring a balance between work and rest to enhance efficiency and a socially responsible lifestyle.

Food, Health, and Malnutrition

• A diet lacking nutrients causes ill-health or malnutrition.
• Malnutrition means poor health due to nutrient deficiency, excess, or imbalance.
• It includes both undernutrition and overnutrition.

Undernutrition

• Undernutrition is a deficiency of calories and/or one or more nutrients in the diet.
• An undernourished person is underweight.

Overnutrition

• Overnutrition is an excess of calories and/or nutrients.
• Excessive calorie intake leads to being overweight and can cause obesity.
• Excessive fat-soluble vitamins can lead to hypervitaminosis or vitamin toxicity.

Kilocalorie (kcal) Defined

• A kilocalorie (kcal) is a unit for measuring the energy value of food and the energy needs of the body.
• It raises the temperature of 1,000 grams of water by 1°C.
• 1 kilocalorie is equal to 4.184 kilojoules (kJ).

Nutritional Status Defined

• An individual's health is influenced by the utilization of nutrients, which determines their nutritional status.
• Assessment is done via food consumed, signs of deficiency, and measurements, as well as blood/urine analysis.

The Link Between Food and Health

• Good nutrition and health are closely related concepts.
• Wholesome/nutritious food boosts health and wards off disease.
• A food handler must uphold hygiene for personal/food purposes.
• A balanced diet is key to ensuring sound health.

Dietary Factors

• Other considerations include food wholesomeness and a clean environment.
• Food handlers must practice high hygiene standards to prevent food-borne diseases.
• Planning meals, hygiene, and nutrition are key
• Maximum health advantages are ensured if everyone involved in purchasing, storing, cooking, or serving food has a fundamental understanding of nutrition.

Functions of Food - Physiological

• Providing Energy
• Body Building
• Maintenance and repair
• Regulation of body processes
• Protection

Main Functions of Food

• Foods serve certain social and psychological purposes.
• The physiological functions include providing energy.
• Body building/growth is a key function.
• Maintenance and repair/protective functions are also.

Psychological Function

• Emotional requirements can be met such as love, attention, and security.
• Food plays a part in fulfilling emotional needs.
• Food can show love/respect.
• Anxiety and frustration may be lessened/increased by food.
• Emotions are linked to the food.

Social Functions of Food

• Food is a way of showing warmth, friendship, respect, or affection
• Food has celebrations for occasions.
• Food is shared to invite people to dine as well.
• Religious events often use food as a major part of it.
• Religious significance is assigned to some foods.

Dietitians Defined

• Dietitians use nutrition science to feed people and educate groups in health, disease, and nutrition.
• They possess qualifications in nutrition and dietetics recognized by a national authority.

Dietitians' Roles and Responsibilities

• Dietitians work in many settings such as the NHS and specialize to oncology and renal disease.
• They are employed in primary and secondary care.
• They work in industry, sport, education and are found in journalism.
• Dietetics Assistant also work under that role.
• Their job is to assist patients choosing the diet.
• They are there to record patient's information regarding weigth and nutrition.
• They also provide dietary consultation.

Community Dieticians

• Assess food and health needs, enable healthier diets, and prevent disease.
• They work with patients to review their progress.
• Offer advice on selection of food.
• Standardizing cooking is part of a dietician role.

Definition of Nutritionist

• The title "nutritionist" is not legally protected and lacks standardized educational requirements.
• The nutrition society seeks to standardize the nutrition profession and protect the title "nutritionist".

The Nutrition Society

• The nutrition society, established in 1941, advances the scientific study of nutrition and its application to human and animal health.
• The objectives of the nutrition society are:
  • promotion of study.
  • set high standards in practice.
  • promote careers.
• public protection.
• The society maintains registers of nutritionists and their ethical guidelines.
• Registration entails demonstrating qualifications and experience.
• Titles awarded include associate nutritionist.
• Registered nutritionists work in public health.