NUTRITION & DIETETICS

By DR. INDRAJEET KUMARTutor

Department of Community Medicine

NUTRITION: The science of food and it’s relationship

to health.

DIETETICS: Practical application of the principles of nutrition, it includes planning of meals for the well & the sick.

CLASSIFICATION OF FOOD

A. CLASSIFICATION BY ORIGIN: 1. FOODS OF ANIMAL ORIGIN e.g meat, fish. 2. FOODS OF VEGETABLE ORIGIN e.g cabbage , carrot etc.

B. CLASSIFICATION BY CHEMICAL COMPOSITION: 1. PROTEIN PROXIMATE PRINCIPALS 2. FAT ( MACRO-NUTRIENTS) 3. CARBOHYDRATE

4. VITAMINS MICRO-NUTRIENTS 5. MINERALS

C. ON THE BASIS OF PREDOMINANT FUNCTION: 1. BODY BUILDING FOOD: Milk, Meat, Egg, fish, Pulses etc. (Protein) 2. ENERGY GIVING FOOD: Sugar, Root, Tubers, Fats & oils (Carb. & fat) 3. PROTECTIVE FOOD: Vegetables, fruits and milk (rich in vit. & minerals)

PROTEIN

PROTEIN

AMINO ACIDSESSENTIAL AMINO ACIDS:- Body cannot synthesize them in amount corresponding to it’s need. Total: 8E.g: leucine, isoleucine, lysine, methionine, threonine, Phenylalanine, valine, tryptophane .Semi-essential: Arginine & Histidine

NON-ESSENTIAL AMINO ACIDS: Body can synthesize them in amount corresponding to it’s need. E.g: asparaginic acid, glutamic acid, proline, serine etc.

BIOLOGICALLY COMPLETE PROTEIN: Protein which contains all essential amino acids are called biologically complete. E.g: Milk protein & Egg protein

BIOLOGICALLY INCOMPLETE PROTEIN:Protein which lack in one or more essential amino acid are called biologically incomplete. E.g: Rice, Wheat, Pulse etc.

SOURCES OF PROTEIN

ANIMAL SOURCE

Milk, Meat, Egg, Fish etc.

VEGETABLE SOURCE

Pulses, cereals, beans, Nuts, Oil seed cakes etc.

SUPPLEMENTARY ACTION OF PROTEIN

MIXED DIET: e.g: cereal with pulse. (rice+dal, Chapati+dal, Dosa+sambhar, idli+sambhar,

khichri)BIOLOGICALLY COMPLETE

Cereals (rice, wheat, maize) deficient in lysine & threonine

but rich in Methionine.BIOLOGICALLY INCOMPLETE

Pulses are deficient in Methionine but rich in lysine & threonine.BIOLOGICALLY INCOMPLETE

FUNCTIONS OF PROTEIN

body building repair and maintenance of body tissue. maintenance of osmotic pressure*. Synthesis of certain substances like, anti-

bodies, enzymes, Hb., plasma protein, hormones, coagulation factors.

ASSESMENT OF NUTRITIVE VALUE OF PROTEIN

1. DIGESTIBILITY CO-EFFICIENT: % of ingested nitrogen absorbed in the body. = nitrogen absorbed X 100

nitrogen ingested

2. BIOLOGICAL VALUE: % of absorbed nitrogen retained in the body.

= nitrogen retained X 100

nitrogen absorbed

3. NET PROTEIN UTILIZATION (NPU) = It is the product of digestibility co-efficient and biological value divided by 100.

= D . C X B . V 100

:- greater the NPU better the protein.

:- NPU of egg is 100. Hence called “Reference Protein”.

:- NPU of protein in indian diet is between 50 – 80.

ASSESSMENT OF PROTEIN STATUS

1. MID ARM CIRCUMFERENCE (for age 1-5yrs) > 13.5cm - satisfactory. 12.5 – 13.5cm – mild malnutrition < 12.5cm - severe malnutrition.

2. CREATININE HEIGHT INDEX3. SERUM ALBUMIN (Normal = 3.5 – 5 gm/dl)

4. TOTAL BODY NITROGEN

PROTEIN REQUIREMENT

As per ICMR (Indian Council of Medical Research) for adult M/F : 1gm / kg body wt. for children : 1.5 gm / kg body wt. During pregnancy : + 14 gm / day. During Lactation : + 25 gm / day.

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