Foods

EAT WELL TO LIVE WELL!

What is food?

• Any substance used for energy, physical growth , development and repair or rebuilding in the body

• Any substance which after consumption helps in producing heat or energy, formation of new tissues, repair of tissue and carrying the physiological processes

What does food do?

• Physical growth and development• Production of energy and power• Maintenance of tissues’ working capacity• Protection against diseases

What is nutrition?

Sum of the processes or activities by which the body receives, digests, absorbs and utilizes food for energy, maintenance and growth.

What is health?

A state of complete physical, mental and social well being and not merely the absence of disease or infirmity.

Optimal HEALTH = Good NUTRITION

Classification of Foods

• Functional classification

• Origin classification

• Chemical classification

• Geographical classification

• Clinical/Medical classification

• Nutritive value classification

Functional classification

Energy providers

Body builders

Protectors

Origin Classification (source)

Animal Sources

Vegetable Sources

Chemical composition

• Proteins• Fats• Minerals• Carbohydrates• Vitamins• Water

Geographical classification

• National foods

• Continental foods

Medical classification

• Full diet

• Soft diet

• Bland diet

• Special diet

• Liquid diet

Nutritive value classification

• Cereals

• Pulses

• Vegetables

• Fruits

• Milk and milk products

• Sugar and jaggery

• Oilseeds

• Fats and oils

• Meat and eggs

• Spices and chillies

• Miscellaneous foods

What is a nutrient?

• Organic and inorganic substances found in the diet

• Two main categories:

–Macronutrients

–Micronutrients

Macronutrients

• Proteins, fats and carbohydrates• Form the bulk of food• Main sources of energy• Also called PROXIMATE PRINCIPALS.

Micronutrients

• Minerals and vitamins• Required in small quantities• Water – vital nutrient – SUPER NUTRIENT

Proteins

Introduction…

• Proteins form the basic structure of all cells in the body

• Body contains about 20% proteins. • Mulder proposed the name “PROTEINS” for

nitrogen dominated biological substances• Proteins derived from a Greek word which

means “ of first importance”

Definition

Proteins are

• nitrogenous compounds which yield amino acids on hydrolysis• essential constituents of all living cells, and • the most abundant of the organic compounds in the body

Composition

• Made of carbon, hydrogen, nitrogen, oxygen, sulphur and phosphorus.

• Nitrogen content – 14 to 20%• This differentiates proteins from fats and

carbohydrates• Protein is made of AMINO ACIDS. • Body requires 24 amino acids of which 8-9 are

ESSENTIAL AMINO ACIDS

Essential Amino Acids

• Body cannot synthesize them in sufficient quantities.

• They have to be obtained from FOOD.• 9 of them are:

– Leucine, Isoleucine, Lysine, Histidine,

Threonine, Phenylalanine, Methionine,

Valine, Tryptophan (ILL HTTV PM)

Required for proper growth

• Arginine, Glycine, Alanine, Serine, Norleucine, Aspartic acid, Glutamic acid, Proline, Hydroxyproline, Citrulline, Tyrosine, Cystine, Hydroxyglutamic acid

Body can synthesize these in proper quantities

These are:

Types of Proteins

• Simple proteins – albumins, globulins, fibrinogel, protamins, Gluteleins, Prolamines, Histones

• Conjugated proteins – nucleoprotein, glucoprotein, phosphoprotein, hemoglobin, lecithoprotein

• Derived proteins – first class proteins (proteins with EAA) and second class proteins

Classification based on EAA

Complete proteins

• They contain all amino acids.

• Fish, meat, eggs, milk, cheese – SOURCES .

• Soyabean protein – first class protein;

• Proteins promote growth

Partial complete proteins

• Partial lack of essential amino acids. • SOURCES- dhal & cereals. • They promote moderate growth.

Incomplete proteins• Complete lack of few or all essential amino

acids. • SOURCES – gelatin and zein of corn. • They promote NO growth

Functions of proteins

• Providing the material for growth and development

• Repair and maintenance of tissues• Providing amino acids for synthesis

of antibodies, enzymes, blood protein and hormones

• Help in growth of foetus during pregnancy and lactation after delivery.

• Maintaining osmotic pressure

Sources of Proteins

• Animal Sources: Milk, eggs, meat, fish (contains EAA )

• Plant sources: Cereals, pulses, oilseeds (deficient EAA)

Requirement of proteins

• Determined by body weight• One gram protein per day per kg – ADULTS• Infant – 0 – 6 months = 2.3 to 1.8 gm/kg/day• Infant : 7 – 12 months = 1.8 to 1.5 gm/kg/day• Child: 1 – 3 years – 1.83 gm/kg/day• 4 – 6 years – 1.56 gm/kg/day• 6 – 8 years – 1.8 gm/kg/day• 9 – 12 years – 1.5 gm/kg/day