CHS%20214

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CHS 214
Lecture 1

• Introduction to the Science of Nutrition and
• Related Definitions

Sara Al-Mosharruf
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Objectives

• Introduction
• Definitions
• Energy from food
• Functions of food nutrients
• Composition of human body
• Nutrition assessment of individual
• Sign of good nutrition
• The relationship of nutrition with other sciences
• Nutrient intake limits

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Introduction

• Most of the organized studies of nutrition have
  been confined to the 20th century.
• Although there was evidence of long-standing
  curiosity about nutrition.
• Hippocrates, the father of medicine(400 BC)
  considered food as one universal nutrient.
• Antonie Lauret Lavoisier(18th century, a French
  chemist) is known as father of nutrition.
• In Islam there are many verses of the Quran and
  Hadeeths in food and nutrition.
• Some of these fact has just been proved by the
  modern science and some not.

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• Nutrition has played a significant role in our
  life, even from before our birth.
• Many people are concerned only with food that
  relives their hunger or satisfies their appetite
  .
• But in many times, these foods don't supply their
  bodies with all the component of good nutrition.

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Definitions
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Food

• Foods are products derived from plants or animals
  .
• that can be taken into the body to yield energy
  and nutrients for maintenance of life ,for growth
  and repair tissues.
• Food is that nourishes the body.
• Food is a prerequisite of nutrition.

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Diet

• Diet is the foods and beverages a person eats and
  drinks.

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Food composition
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• Nutrients
• Chemical substances obtained from foods used in
  the body to provide energy, structure materials,
  regulating agents to support growth, maintenance,
  repair of body's tissues and may also reduce the
  risks of some diseases.

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Nutrients divided into two
categories

• Macronutrients
• Are the nutrients which the body needed in large
  amount such as carbohydrate, protein and fats.
• Carbohydrates, protein and fats are the main
  source of energy for human body.
• Are the energy yielding nutrients.

• Micronutrients
• Are nutrients needed in lesser amounts such as
  Vitamins minerals.

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Chemical composition of the nutrients
?Organic nutrients substance that contain carbon
atom. ?Inorganic substances that do not contain
carbon atoms.
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Essential nutrients

• Are nutrients a person must obtain from food
  because the body cannot make them for itself
  insufficient quantity to meet physiological
  needs. Also called indispensable nutrients.

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Nutrition

• Nutrition is the science of foods, nutrients and
  other substances they contain their actions
  within the body (including ingestion, digestion,
  absorption, transport, metabolism and excretion).
• A broader definition includes the social,
  economic, cultural, and psychological
  implications of food and eating.

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Nutritional requirements

• The amounts of nutrient which are needed for
  covering the human needs to be healthy depend on
  sex, age and few other factors.

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Nutritional status

• An individual condition of health in relation to
  digestion and absorption of nutrients.
• Nutritional care
• Application of the science of nutrition in
  nourishing the body regardless of health problems
  or potential problems.

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• Adequate diet is a diet providing all the needed
  nutrients in the right total amounts.
• Junk food
• Refers to foods that are harmful.

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Calories

• The energy released from carbohydrates, proteins
  and fats can be measured in calories.
• A calorie is the amount of heat necessary to
  raise temperature of 1 gm of water by 1 C.
• 1000-calorie metric units are known as
  kilocalories (kcal).
• Empty-kcalorie foods
• a popular term used to denote foods contribute
  energy (from sugars, fat or both)
• but lack in protein, vitamins and minerals
  Example(potato chips and candies).

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Dietetics

• the health profession responsible for the
  application of nutrition science to promote human
  health and treat disease
• Metabolism
• The sum of all chemical reactions that take place
  in the body which it maintains itself produces
  energy for its functioning.

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Nutrition science

• Nutrition science
• 1-The study of nutrients and other substances in
  foods and the body's handling of them.
• 2-Its foundation depends on several other
  sciences including biology, biochemistry, and
  physiology.
• 3- Comprises the body of knowledge governing the
  food requirement growth, activity, reproduction
  and lactation.

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Nutritional genomics the science of how
nutrients affect the activities of genes and how
genes affect the interactions between diet and
disease.
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Malnutrition Malnutrition has two types

• Undernutrition deficient energy or nutrients.
• Symptoms of under nutrition (extremely thin,
  losing muscle tissues, prone to infection and
  disease, skin rashes, hair loss, bleeding gum and
  night blindness).
• Overnutrition excess energy or nutrient.
• Symptoms of overnutrition (heart disease,
  diabetes, yellow skin, rapid heart rate and low
  blood pressure).

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Nitrogen balance

• The proteins in the body undergo constant
  turnover (degraded to amino acids and
  resynthesized).
• Nitrogen balance is the difference between the
  amount of nitrogen taken into the body each day
  and the amount of nitrogen in compounds lost.

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• if 1- More nitrogen is ingested than excreted, a
  person is said to be in positive nitrogen balance
  (growing individual such as children and
  pregnant).
• 2- Less nitrogen is ingested than is excreted
  (negative nitrogen balance, person eating either
  too little protein or protein is deficient in one
  or more of the essential amino acids, new protein
  cannot be synthesized and the unused amino acids
  will be degraded, body function will be impaired
  by the net loss of critical proteins.
• 3- In contrast, healthy adults are in nitrogen
  balance and the amount of nitrogen consumed in
  the diet equals its loss in urine.

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Nutritive value

• The amounts of nutrient which the food consist
  of, determined by using
• Food analysis.
• Food analysis tables.

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Energy from food

• The amount of energy a food provide depends on
  how much CHO, fat, and protein contains.
• When completely broken down in the body,
• 1 gm CHO ?4 kcal of energy
• 1 gm protein? 4 kcal of energy
• 1 gm of fat ? 9 kcal of energy
• ?therefore fat has the greater energy density
  than either CHO or protein.
• Alcohol is not considered a nutrient because it
  interferes with health but it yields energy
• 1 gm of alcohol? 7 kcal of energy

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Functions of food nutrients

• 1-Provide energy sources
• 2-Build tissues
• 3-Regulate metabolic process

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• 1-Provide energy sources
• The major carbohydrates in the human diet are
  starch, sucrose, fructose and glucose.
• Dietary carbohydrate (starches and sugars)
  provided the body's primary source of fuel for
  energy.
• Oxidation of carbohydrates to CO2 and H2O in
  the body produces approximately 4 kcal/g.
• They also maintain the back-up store of quick
  energy as glycogen (animal starch).

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• Fats are lipids composed of triacylglycerols.
• A triacylglycerol molecule contains three fatty
  acids esterified to one glycerol molecule.
• Dietary fats, from both animal and plant
• sources, provided the body's secondary or
  storage form of energy.
• It is a more concentrated, yielding 9 kcal for
• each gram consumed.
• In a well-balanced diet, protein provided about
  15 of the total kcalories.
• Each gram of protein can yield 4 kcal.

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• How to calculate the energy available from 1
  slice of bread with 1slice of bread with 1
  tablespoon of peanut butter on it contains 16
  grams carbohydrate, 7 grams protein and 9 grams
  fat?

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2-Build tissues

• Proteins are composed of amino acids that are
  joined to form linear chains.
• The digestive process breaks down proteins to
  their constituent to amino acids, which enter the
  blood.
• The primary function of protein is tissue
  building and repairing body tissues.
• Dietary protein provides amino acids, amino
  acids are the building unit necessary for
  construction and repairing body tissues.
• Muscle protein is essential for body movement.
• Other proteins serve as enzymes.
• Other nutrients such as minerals and vitamins
  used in tissue building and maintaining tissue.

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• Minerals are also found in the fluids of the body
  and influence their properties.
• There are 13 different vitamins, one vitamin
  enables the eyes to see in dim light,
• protect the lungs from air pollution
• make the sex hormones,
• stop the bleeding,
• helps repair the skin,
• replace old blood cells and lining of the
  digestive tract.

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3-Regulate metabolic process

• Many vitamins and minerals function as coenzymes
  factors in cell metabolism.
• Other nutrients (water and fibers),
• water provides the environment in which
  nearly
• all the body's activities.
• Also, in many metabolic reactions and
  supplies the medium for transporting vital
  materials to cells and waste products away from
  them.
• Dietary fibers help regulate the passage of
  food material through the gastrointestinal tract
  and influences absorption of various nutrients.

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Composition of human body
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Nutrition assessment of individual

• Evaluation of person's nutrition
• 1- Historical information (socioeconomic status,
  drug use, diet and person's family history).
• 2-AAnthropometric data (height and weight).
• 3- B biochemical data (Laboratory tests).
• 4-Cclinical assessment(Physical examinations)
• 5-DDietary assessment

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Sign of good nutrition

1. Well-developed body.
2. Ideal weight.
3. Good muscle development.
4. The skin is smooth and clear
5. The hair glossy and the eyes clear and bright.
6. Appetite, digestion and elimination are normal.
7. Have good resistance to infection.

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The relationship of nutrition with other sciences
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• There are three main areas of overlapping between
  nutrition and medicine
• 1-dietary control of disease.
• 2-the relationship between diet as a possible
  causative factor in disease ex cancer, heart
  diseases etc.
• 3-the toxicology of natural and processed foods.

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Nutrient intake limits
Accurate View
Danger of toxicity
marginal
Safety
RDA
Safety
marginal
Danger of deficiency
Naive View
Safety
RDA
Danger
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• Thank you for listening ?