Unit 1: Principles of Nutrition

1. Introduction to the basic nutritional concepts and terms.

2. Discuss the classification of nutrients.3. Discuss the scope and importance of

Nutrition and Health4. Discuss the factors influencing food habits.

basic nutritional concepts

1. Nutrition: is defined as the science of food and its relationship to health.

• It includes everything that happens to food. It is the study of nutrients and processes by which they are used by the body.

2. Dietics: It is the practical application of the

principles of nutrition which includes planning of meals for the healthy as well as the sick. • E.g: eat less meat, do not eat till you feel full,

read labels before you chose to buy,,,,,

3. Food: anything eaten or drunk, which meets the

needs of tissue building, regulation and protection of the body and its energy needs.

4. Diet: refers to whatever people eat, drink each day. It includes the normal diet people consume and the diet people consume in groups (Hotel diet) but will also be modified for the sick as part oftheir therapy (Diet therapy).• It is according to the need of the body i.e:

considering its health conditions

5. Nutrients:Useful chemical substances derived from the food by

the body are called nutrients. • Nutrients include:1. Carbohydrates2. Lipids3. Proteins4. Water5. Minerals6. Vitamins

classification of nutrients.

1. Major nutrients (Macronutrients): Carbohydrates, lipids, proteins and water.

2. Minor nutrients (Micronutrients): Vitamins and minerals.

The Major Nutrients

• Major nutrients are called Macronutrients.

• Are utilized for energy or are stored as fat.e.g: Carbohydrates, lipids, proteins and water.

The Minor Nutrients

• It is also called micronutrients (needed in trace amount).

• do not supply energy or calories, instead they regulate the metabolism.

E.g: vitamins and minerals ( iron and zinc)

NUTRITION AND HEALTH

• How nutrition is related to health? • The basic study of nutrition is of primary

importance as: 1. It is fundamental for our own health, and• 2. It is essential for the health and well being

of our patients and clients from the time of eating till it is utilized for various functions.

Functions of Nutrition

1. Nutrition helps growth and development2. Prevents malnutrition3. Resists infection and4. Prevents diseases (decrease morbidity and mortality)

1. Nutrition helps growth and development

• According to Mental Health Organization in UK:

Nearly two thirds of those who do not report daily mental health problems eat fresh fruit or fruit juice every day. This pattern is similar for fresh vegetables and salad. Those who report some level of mental health problem also eat fewer healthy foods (fresh fruit and vegetables, organic foods and meals made from scratch) and more unhealthy foods (chips and crisps, chocolate, ready meals and takeaways).

• A balanced mood and feelings of wellbeing can be protected by ensuring that our diet provides adequate amounts of complex carbohydrates, essential fats, amino acids, vitamins and minerals and water.

https://www.mentalhealth.org.uk

2. Prevents malnutrition

• Malnutrition means an undesirable kind of nutrition leading to ill health. It results in a lack, excess or imbalance of nutrients in diet.

• It includes under nutrition and over nutrition: 1. Under nutrition is a state of an insufficient

supply of essential nutrients. 2. Over nutrition refers to an excessive intake of

one or more nutrients which creates a stress in bodily functions.

Causes of malnutrition

• Malnutrition is directly responsible for certain specific nutritional deficiency diseases like kwashiorkor, marasmus, vitamin A deficiency, anaemia, goiter etc.

• Good nutrition is therefore essential for prevention of disease and promotion of good health.

Resistance to Infection

• Malnutrition predisposes the body to infections like tuberculosis,,,,,,,,,.

• Infections in turn aggregate malnutrition and metabolism.

Mortality and Morbidity

• Thus, food plays a prominent role in providing physical, mental and social well being which is the WHO definition of health.

• Thus food reduces incidences of disease therefore it reduces morbidity rate (death rate).

Factors influencing food habits:

1. Superstitions2. Social and cultural factors3. Religions factors4. Income5. Geography/availability6. Advertising and media

Superstitions and Cultural Factors

• Food habits are handed over from generation to generation.

• Though these factors have very little or no scientific basis, people rigidly adhere to them.

• E.g: In many parts of India pregnant women are not allowed to take papaya and Pineapple (cause abortion)

• milk with saffron result in a baby with a very fair complexion

• In parts of Bengal, people believe that consumption of tongue of goat by children will make them more talkative.

Religious Belief

• Hindus do not eat beef, and among Hindus some communities do not eat fruits, onions and garlic. Many Hindus are vegetarians. To eat meat is to destroy the seeds of compassion.

• Islamic food laws prohibit the consumption of “unclean” foods such as swine and animals killed in a manner that prevents their blood from being fully drained from their bodies

• Jews do not eat pork and shellfish

Child Rearing Practices• in India late introduction of weaning foods,

prolonged breastfeeding and the adoption of commercially produced baby foods

Baby, 4 months, is fed soft food, fruit or vegetables, AS WELL AS breastmilk. http://rehydrate.org/dd/su32.htm

Baby, 9 months, eats mashed food

Geography/Availability

• In the olden days, man would eat what ever was available to satisfy his hunger. The food he got was the type he could cultivate in hislocality. • The nutrition value of natural foods do not vary from

country to country. But there is a great variation in the composition of prepared

foods such as bread, biscuits, cakes etc., due to variation in recipes and basic ingredients used in different regions.

Income

• Financial resources determine the type of food we consume.• Depending on the availability one selects the

food. People in lower income groups in India consume, a combination of cereals and cheaply available green leafy vegetables, roots and tubers.

• People of higher income groups, can choose food from all groups irrespective of season.

• Classification, functions, role and medicinal value of food

• Questions for students for next class295 - 299

• Understand the concepts of My Pyramid and apply in daily living

• 299• One of the most helpful,easy to use diet planning tools is the food guide Pyramid (Fig. 21.1).

• The placement of this five food groups on the pyramid emphasizes their role in the diet. The grains that form the base should serve as the foundation of a healthy diet because breads, cereals, rice and wheat are high in carbohydrates and low in fat.

• The grains are followed by fruits and vegetables which supply the vitamins, minerals and fiber.

• The next level suggests eating smaller amounts of dairy products as well as meat, poultry, fish, beans, eggs and nuts. While foods from these group provides proteins, calcium, iron, zinc and other nutrients, they contain large amount of fat and should be chosen carefully.

• Not considered one of the food groups, the tip of the pyramid consists of fats, oils and sweets. They supply lot of fat and/or calories and few nutrients. These items should be added to diet cautiously.

What Counts as One Serving? • According to U.S. Department of Agriculture: The amount of food that counts

as one serving is listed below. If you eat a larger portion, count it as more than 1 serving.

• Milk, Yogurt, and Cheese 1 cup of milk or yogurt 1¹⁄₂ ounces of natural cheese 2 ounces of processed cheese Meat, Poultry, Fish, Dry Beans, Eggs, and Nuts 2-3 ounces of cooked lean meat, poultry, or fish 1¹⁄₂ cup of cooked dry beans, 1 egg, or 2 tablespoons of peanut butter count as 1 ounce of lean meat

• Department of Health and Human Services Vegetable 1 cup of raw leafy vegetables ¹⁄₂ cup of other vegetables, cooked, or chopped raw ³⁄₄ cup of vegetable juice Fruit 1 medium apple, banana, orange ¹⁄₂ cup of chopped, cooked, or canned fruit ³⁄₄ cup of fruit juice Bread, Cereal, Rice, and Pasta 1 slice of bread 1 ounce of ready-to-eat cereal ¹⁄₂ cup of cooked cereal, rice, or pasta.

• No specific serving size is given for the fats, oils, and sweets group because the message is USE SPARINGLY.

• Define calorie.

• The qualitative food requirements are estimated in term of energy is calories.

• Physiologic calorie or kilocalorie is the unit of energy, which is the amount of heat necessary to raise the temperature of one kilogram of water by 1ºC, from 14.5ºC to 15.5ºC. often used to measure the energy value of foods.

• 1 kilocalorie = 42 kilojoules

PRODUCTS OF DIGESTION(Energy Nutrients)

CHO

FATS

PROTEINS

GLUCOSEFRUCTOSEGALACTOSE

FATTY ACIDS GLYCEROL

AMINO ACIDS

Gastro-intestinal

System

Calorie Value of Food

• (kilocalories/gm):

Carbohydrates 4Fat 9Proteins 4

Definition of BMR

• BMR is defined as the energy expenditure of a subject at complete physical and mental rest, awake (and not during sleep) having normal body temperature and in the post absorption state (12 hours after the last meal) and 8–12 hours after any significant physical activity.

• You can visit the following page for calculation:http://www.bmi-calculator.net/bmr-calculator/

Basal metabolism (Basal Metabolic Rate BMR)

• The BMR is the energy expenditure necessary to maintain basic physiologic conditions such as:

a. The activity of the heartb. Respirationc. Conduction of nerve impulsesd. Ion transport across membranese. Reabsorption in the kidney, andf. Metabolic activity such as synthesis of macromolecules under standard conditions.

• About 60% or more of the energy the average person spends goes to support the ongoing metabolic work of the body’s cells, the basic metabolism. This is the work that goes on all the time, without conscious awareness.

• E.G: The beating of the heart, the inhaling and exhaling of air, the maintenance of the body temperature and sending the nerve and hormonal messages to direct these activities are the basal procedures that maintain life.

• Basal metabolic needs are surprisingly large. A person whose total energy expenditure amounts to 2000 calories per day spends as much as 1200–1400 calories to support usual metabolism.

• The basal metabolic rate accounts for about 60 to 75% of the calories you burn every day.

Factors Affecting BMR

• BMR differs among different individuals. It depends on:

a. Variable factorsb. Invariable factors

a. Variable Factors Affecting BMR

a. Nutritional state: BMR is low in starvation and undernourishmentas compared to well fed state. Starvation leads to an adaptive decrease in BMR, which results from a decrease inlean body mass.

b. Body size or surface area: The BMR is directly proportional to thesurface area of the subject. Larger the surface area, greater willbe the heat loss and equally higher will be the heat productionand BMR.

• c. Body composition: The BMR is proportionate to lean body mass (LBM).

• LBM is the body weight minus non-essential (storage triacyl glycerol) weight. Adipose tissue is not as metabolically active as lean body mass. BMR is often expressed as per kilogram of lean body mass or fat free mass. Therefore, higher the percentage of adipose tissue in the body lower the BMR/ kg body weight.

d. Endocrinal or hormonal state: In hyperthyroidism, the BMR is increased and in hypotheroidism it may be decreased by up to 40%, leading to weight loss.

e. Environmental temperature or climate: In colder climate the BMR is higher and in tropical climate the BMR is proportionately low. Stress, anxiety and disease states, especially infections, fever, burns and cancer also increases the BMR.

f. Drugs: Smoking (nicotine), coffee (coffine) and tea (theophylline) increase the BMR whereas β-blockers tend to decrease energy expenditure

Invariable Factors Affecting BMR

a. Gender or sex: The BMR of males is slightly higher than that offemales particularly due to:

i. Womens lower percentage of muscle mass (lean body mass)and higher percentage of adipose tissue (that has lower rateof metabolism) when compared to men of the same bodyweight, and

ii. The difference in sex hormone profile of the two genders.b. Age: Decrease in BMR with increasing age is probably relatedto loss of muscle mass (lean body mass) and replacement ofmuscle with adipose tissue that has lower rate of metabolism.

Normal Value of BMR• BMR values are expressed as K cal or KJ per square

meter of body surface per hour. In adults BMR for :- Healthy males is 40 K cal (168 KJ) per hour and healthy females is 37 K cal (155 KJ) per hour.• This means that the total caloric expenditure in 24

hours to complete basal state is 1800 K cal (7500 Kj) for adult males and1400 K cal (5859 KJ) for females assuming that the total bodysurface across are 1.8 sqm and 1.6 sqm respectively.

Clinical Applications of BMR

a. BMR estimation is used to diagnose thyroid disorders.b. BMR is used in calculating food and drugs.

PHYSICAL ACTIVITY• P 304• Physical activity is the largest variable affecting energy

expenditure and represents 20–40% of the energy expenditure.• The reference man is in the age group of 20- 39 years. With a

weight of 55 Kgs without any disease and with a capacity to perform 8 hours of moderate activity. When not engaged in work, a reference man spends 8 hours in bed and 4 to 6 hours in moving around or in a sitting position and 2 hours either walking or doing household activities.

• In the case of a reference woman, the difference is only in her body weight (45 Kg). Instead of the physical activity of the

occupation, the woman does household duties. Other conditions are the same in case of a reference man.

• The energy expenditure for men and woman is calculated considering their internal and external activities. The FAO /WHO expert group (1983) made the following recommendations (Table 21.1).

• Additional energy is needed for the growth of the foetus, placenta and tissues during pregnancy. The BMR is also increased due to increased internal activities.

• Daily 150 K cals during the first semester and 300 K cal during

the rest of the pregnancy is recommended. The energy cost during the term of pregnancy is 62,500 K cals.

• Additional energy requirements during lactation is for the secretion of milk. For a normal output of 850 ml per day, during the first six months, 550 K cal per day is recommended.

• The activities which demand maximum energy are in the following order.

• Walking very fast, severe exercise, running, swimming, labourer’s work, carpentry, metal and industrial work, walking slowly, laundry work and ironing.

Energy intake and expenditure

•?

Thermogenic effect of food ?• Thermic Effect of Food (TEF) is the energy

used to digest food and absorb and further process the nutrients recently consumed.

• It is called diet induced thermogenesis. is energy spend for digestion, absorption and storage of food. It is about 5-10% of total energy expenditure.

• Dudek. G. susan, Nutrition essentials for Nursing Practice, 7th edition, 2014, Lippincott.

Page 156-160

• Classification of Activities Based on Occupation Sedantary Male

• Teacher, tailor, priest, executive, shoe maker, retired personnel, landlords peon.

• Female: Teacher, nurse, house wife, executive.

• Moderate Male• Fisherman, weaver driver, porter, fitter, turner,

carpenter, agricultural labourer.• Female : Servant maid, basket maker, beedi

maker.• Heavy male: Stone cutter, blacksmith,

mineworker, wood cutter.• Female: Stone cutter etc.

• Understand the role of the nurse in Nutrition.

• Role of the nurse (appendix 1)

•

Questions?

• • Identify the 6 food groups based on the Omani dietary guidelines

•questions

Food groupsFood servings

• http://wholegrains council.org/files/Oman/DietaryGuidelines.pdf

Proper food handling and hygienic practices

Thank You