Human Nutrition

SupervisionProf. Dr. Mervat Salah

- By the end of this lecture, students will

have a general overview on the body

composition.

- As well as some basics of energy.

Intended Learning Outcomes

Facts about Body weight

Body is composed – water, fat, muscle, bone,minerals

Composition varies with age Controlled by hormones, diet,

exercise, stress etc. Body Mass Index = wt (kg) / ht 2 (m)

Ideal range = 19 – 23 for Indians Over weight BMI is > 23 – 26, Waist to Hip ratio (WHR) – Central obesityobese >27Ideal = 0.8

Nutrition & wellness - Nutritional perspective. Drmervat salah.

Body Mass Index indicator of health risk

eg – 75 kg / 1.7 X 1.7 m = 26 BMI class Presumptive diagnosis

< 18.5 Underweight 18.5 - 22.9 Normal 23 - 24.9 Overweight > 25 Obese

Nutrition & wellness - Nutritional perspective. Drmervat salah.

Composition Of The Body A normal chemical composition for a

man wieghing 65kg is protein……….11kg……17 % fat………………9kg.......13.8% cho……………..1kg…….1.5 % water………….40kg…….61.6% minerals………..4kg……..6.1%

Functions Of The FoodThere are several biological functions

of food :

1- Source of energy (fat and cho ) 2- building material ( pt and ca, ph ) 3- regulating and protective agent

NUTRIENTS – sources,functionsNUTRIENT BODY FUNCTION FOOD SOURCES

Carbohydrate Energy, protein sparing – 4kcal/g

Cereals, pulses, veg, fruits

Protein Growth, repair, energy, enzymes, antibodies, hormones

Pulses, meat, fish, milk products, egg,cereals

Fat (lipid) Energy, EFA, fat-sol vit, insulation.

Fats, oils, meat, fish, nuts dairy products

Minerals Skeletal, growth , blood clotting, immunity

Dairy, GLV, fruits, whole grainsmeat, veg, legumes, organ meatnuts

Vitamins Vision, immunity, bone, teeth, metabolism

Nutrition & wellness - Nutritional perspective. Dr. Mervat salah

NUTRIENT SUPPLY

FOOD Amount Energy Protein CHO Fat

g/ml Kcals g g g

1. Cereals 100 350 6-12 60-70 1-22. Pulses 100 340 18-25 60 1-5 3. Milk 100 65 3-5 8 4-64. Vegetables 100 35- 55 1-2 8-15 -5. Oils / fats 20 180 - - 206. Fruits 100 30-55 1-1.5 10-15 -7. Sugar 20 80 - 20 -8. Meat 100 80-140 12-22 - 3-13

Energy Value Of Food

1gm of Fat give 9 calories 1gm of Protein give 4 calories 1gm of carbohydrates give 4 calories carbohydrates and fats are the preferred energy sources , protien will be used for energy if cho and fats are not available in the diet and may build up of toxic byproduct (ketones) in the blood .

Sources of FuelProtein, Fat, Carbohydrates

Substrate choice dependsІ

Intensity & duration of exerciseFitness levelDietary intake

Energy is used in 3 ways

1 – Digesting food 10% 2 - Physical activity 25% 3 - Basal Metabolic rate ( BMR) 65% BMR – all functions that support life 24 hours

Can’t change the percent But You can change your energy demand

Basal metabolic rate(BMR)

(BMR) is affected by several factors : 1-Body composition and surface area . 2- Sex women lower than men . 3-Age the highest rate during infancy . 4- Body temperature increase in cold fever 5-Physiological status decrease in starvation ,increase in illness . 6- Effects of hormones thyroxin

Energy RequirementsEnergy requirements are affected by : - Body size

-Basal metabolic rate -Activity -Pregnancy (300cal) -Lactation (500 cal) -Age -Climate (worm climate need less cals )

Total Daily Energy Requirement

TDR = BMR + EEA + SDA TDR = total daily requirements BMR = basal metabolic rate EEA = energy expenditure of activity SDA = specific dynamic action of food

BMR For adults BMR = Ideal Body weight x 25

decease 2% every 10 years after age 20

For age less than 20 years BMR =1kcal / m2 /hr - or - 55 – age (yr) the area of the body from tables

Energy Expenditure Of Activity

-EEA deferent from one to one , -the average rang 1.1 to 8.4 cal /kg /hr -the easy way is : no active = 400 to 800 cal or 20%of BMR light active=800 to1200 cal or 30% of BMR moderate =1200 to1800 cal – 40%of BMR very active=1800 to 3000cal _50%of BMR

Specific Dynamic Effect Of Food

It is the calorigenic effect of the food or the calories need for the digestion absorption transport process of the food protein consume 15 % of its given cals carbohydrates 6% of its given cals fats consume only 2% of its given cals

AssignmentRana fathi el zemrany

Recommended text book

Manual dietetic book