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Food classification
Non Vegetarian (Animal origin) (complete)
Vegetarian (Plant origin) (incomplete)
Protein Body Builders Carbohydrates Energy Givers
Fats
Minerals and Vitamins Protective [email protected]
Balanced diet
Definition : Equal proportion of all food groups 1: 1:4 (P.F.C)How to select ?
Cheap, easily available, palatable, digestible +
roughage.
+ Essential nutrient
+ Balanced limiting substance
+ 4 major group Milk, Meat, Cereals ,G.L.V. [email protected]
Body weight : Under nourished or obese
Protein requirement: 1gm and 2gms /day Calorie requirement : Socio Culture factors, economic status Balanced ? Vitamins,Minerals, Essential AA,Roughphage Energy expenditure : Physical activity,BMR,
Rq
Energy metabolism
What is calorie ? Mention calorific value of carbohydrates , protein , lipids .Calculate energy req for 55kg male medical student ?Why during pregnancy and lactation addition calorie is taken
Calorific value:
Energy content of food is measured in kilocalories
Defn: One calorie is the heat required to raise the temperature of 1 g of water through 10C
Instrument: Bomb calorimeter
Calorie requirement (55 kg)
30 – 35 kcal / kg body wt
Sedentary workers - 2000 to 2200
Moderate workers - 2400 to 3000
Heavy workers - 3000 to 4000
Pregnancy: + 300 kcal/day Lactation: + 500 kcal/day
Calorie distribution :
Carbohydrates: 60 – 65% (4 kcal/g)
Lipids: 15 – 20% (9 kcal/g)
Proteins: 10 – 15% (4 kcal/g)
Energy requirement (or) expenditure by an
individual depends on:
Basal Metabolic Rate (BMR).
Specific Dynamic Action (SDA).
Physical activity.
Basal Metabolic Rate (BMR)
Rate of energy production under basal conditions per unit time and per square meter of body surface
Basal conditions awake / rest fasting normal temperature / pressure / humidity
Basal Metabolic Rate (BMR)
Energy required during physical / emotional /
digestive rest
Energy required to sustain vital functions
Measurement of BMR Benedict-Roth apparatus Indirect calorimetry
Normal Value Male: 34 – 37 Kcal/m2/hr Female: 30 – 35 Kcal/m2/hr
Factors affecting BMR
Age Sex Climate Exercise Hormones: BMR : Catecholamines T3, T4 Growth hormone
Clinical significance
Increased BMR Decreased BMR fever starvation hyperthyroidism hypothyroidism leukemia cardiac failure
Respiratory quotient
RQ = CO2 produced {L/g}
O2 consumed RQ for diet carbohydrate = 1 fat = 0.7 protein = 0.8 [C6H12O6 + 6O2 6CO2 + 6H2O]
Person takes 250 gms of carbohydrates
4kcalX250=1000 produced theoretically
but 10% will be used for digestion and
absorption
i.e. :100 kcal will be lost =1000-100=900
Specific Dynamic Action (SDA): (Thermogenic effect of food)(Diet induced thermogenesis)
Increased heat production (metabolic rate) following intake of food
It is due to energy expenditure for 1) digestion and absorption of nutrients 2) synthesis of glycogen, TAG, proteins (energy reserves)
Extra energy should be provided to account for the loss of energy as SDA
Values of SDA Protein = 30% Lipids = 15% Carbohydrates = 5% Mixed diet = 10%(100 gm of protein: energy available is 30% less then the calculated value)
Open book 7
Mention different classes of workers ?
Doctors and students comes in which type ?
Physical activityTypes Energy requirement
Sedentary + 30% of BMR
Moderate + 40% of BMR
Heavy + 50% of BMR
Energy requirement
Calculation (55 kg, male, moderate worker) BMR: 24 X 55 kg 1320 kcalPhysical activity: 40% of BMR = 528 kcal 1848 kcal + SDA: 10% calories 184 kcal Total energy required 2032 kcal
Can you calculate for your own now ?
BMR: …………X ………………. =…………………….. kcal
Physical activity: ……….% of BMR … = ……………… kcal
+ SDA : …………% calories = ……………………
Total energy required = ………………… kcal [email protected]
Nutritive value of food items
Food (per 100 gm) energy (kcal) Cereals / pulses 300 Vegetables 20 Potato 100 Milk 60 Meat 100 Egg / fish 170
Calorie content of common food
Chapatti (30 gm) 100 Cal
Masala Dosa 200 Cal
Samosa (1) 150 Cal
Puri (1) bhaji 350 Cal
Upma (one small bowl)
100 Cal
Rice- dal- papad 280 Cal [email protected]
Calorie content of common food
Chicken (70 gm) 100 Cal
Ice cream (100 ml) 350- 400 Cal
Payasam (100 ml) 250 Cal
Tea/coffee (200 ml) 80 Cal
Gulab jamun (2) 250 Cal
Rasogolla (2) 150 Cal [email protected]
Energy expenditure
Activity kcal/hr(BMR +)
Writing 30
Walking 150
Cycling (2km/h) 175
Running 490
Swimming (3.5 km/h) [email protected]
Importance of carbohydrates
Dietary carbohydrates available unavailable( starch, sugar) (fiber)Starch: cereals, pulses, potatoSucrose: avoided in diabetes cause hyperlipidemia
Artificial sweeteners:
a) Saccharin: Benzoic sulfimide b) Aspartame: Phenylalanine Aspartic acid
Nutritive sweeteners – Fructose, polyols
Non nutritive sweeteners – Saccharin, aspartame, acesulfame-k, sucralose
Dietary FiberDefn: Unavailable or indigestible carbohydrate in diet Sources: vegetables, green leaves, fruits Function: Maintenance of normal motility of GIT RDA: 30g/day Eg: Cellulose, hemi-cellulose Lignin, Pectin
Clinical applications
Dietary fibers are used in the treatment of Diabetes mellitus (reduces blood glucose) Cardiovascular disease (reduces
Cholesterol) Colon cancer Constipation Obesity
Biochemical mechanisms
Diabetes mellitus 1) dietary fibers slows emptying of stomach
reduces postprandial hyperglycemia 2) reduces insulin secretion
reduces the rebound fall in blood glucose reduces appetite
Cardiovascular disease
Fibers reduces cholesterol levels by 1) reducing reabsorption of bile acids 2) binding dietary cholesterol
Prevents absorption
Colon cancer / Constipation
1) helps in water retention
produces softer stools 2) increases bulk of the stool
induces gut peristalsis constipation
Open book 10.
What is glycemic index(GI) of food ? Clinical condition where it should high GI food should be restricted
Glycemic index Index used to assess the glycemic response
(glucose absorption) to nutrients
Assessed by the glucose tolerance test after the particular diet and comparing it with a reference meal ( 50gm sugar ).
Glycemic index =
Incremental area under GT curve after 50gm test meal Incremental area under GT curve after 50gm reference meal
1 Hr 2 Hr 3 Hr
50100 150 175 200
Bl.gluReference meal
Test meal
× 100
(mg/dl)
GI: simple sugars > complex carbohydrates GI is low when sugar combined with Protein, Fat
or fiber. Eg: Bread: 70 – 79 Rice : 70 – 79 Banana: 60 – 69 Ice cream : 35 – 40
Importance of lipids
Dietary fat 1) visible fat fat consumed as such eg: butter, ghee, oil 2) invisible fat fat present in other food items eg: fish, meat
Open book 11.
What is RDA of fat in a diet ?
Clinical condition where high fat should be avoided Which oil is good for health ?.
Recommended daily intake
15-20% of total calories PUFA: 25-30% SFA: < 10% Cholesterol < 250 mg Cholesterol rich: egg yolk, liver, brain Cholesterol free: vegetables, cereals, pulses
W 3fatty acid,
Essential fatty acid
Trans fatty acid
What do mean by ?
Sources?
Beneficial effect : -
Give some examples
Harm full effect if taken in excess
Essential fatty acids :
Poly unsaturated fatty acids Sources: vegetable oil, fish oil Uses: Reduces cholesterol level Anti atherogenic Deficiency: fatty liver, dermatitis
Omega -3 fatty acids Source: fish Uses: reduces LDL / VLDL
Trans fatty acids
Source: dairy products, hydrogenated oil Adverse effects: atherogenic ( HDL, LDL) insulin resistance endothelial dysfunction
What are precautions to be taken while prescribing diet CVD Hypolipidemic diet To decrease LDL and increase HDL and
cholesterol excretion Decrease TFA MUFA 1/3rd ,PUFA 1/3rd and 1/3rd saturated fat Plant origin & fish
Nutritional importance of Proteins
RDA: 1g / kg body weight /day Complete / first class / reference protein eg: egg protein milk protein (lactalbumin) Incomplete protein eg: cereals, vegetables Mutual supplementation pulses: cereals – 1:5
Nitrogen balance
Nitrogen intake = Nitrogen excretion Positive nitrogen balance Intake > excretion Conditions : growth pregnancy Hormones : growth hormone insulin
Negative nitrogen balance: Intake < excretion Conditions: malignancy malnutrition diabetes burns / trauma
hormones: corticosteroids
Quality (nutritional value) of proteins
Can be assessed by Nutritional indices
1) Biological value 2) Net protein utilization 3) Protein efficiency ratio 4) Chemical score
Biological value of protein (BV):
BV = Retained nitrogen X 100 Absorbed nitrogen
Eg: egg – 90 milk – 84 wheat - 58 meat - 80
Net protein utilization (NPU):
Retained nitrogen x100 Intake nitrogen denotes quality and availability of protein
Eg: egg – 91 milk – 75 wheat - 47 meat - 76
Net dietary protein value (NDPV):
Used in assessment of both quantity and quality of the proteins in the diet
NDPV = Intake of N x 6.25 x NPU
Protein efficiency ratio (PER):
Weight gain per gram of protein taken
Eg: egg – 4.5 milk – 3.0 wheat – 1.7 meat – 2.8 soyabean – 2.0
Chemical score ( Amino acid score) : used to express essential amino acid contentAmino acid score = content of limiting amino acid in test protein x 100content of limiting amino acid in reference protein eg: egg – 100 milk – 65
Balanced diet
A diet which supplies proportionate quantitiesof all essential nutrients to meet the bodyrequirementBalanced diet should be based on Locally available foods Easily digestible and palatable Should contain enough roughage materials Fit with local food habits / economic means of the
people
Basic food groups
Milk group: dairy products
Meat group: meat, fish, egg, pulses/beans
Green leafy vegetables / fruits group
Cereal groups
Diet for 60 kg sedentary men
veg non veg Cereals 350 g 350 g Pulses 75 g 60 g Oil 40 ml 25 ml Milk 250 ml 150 ml Vegetables 200 gm 200 gm Fish / meat 60 gm
ObesityCauses Genetic influences (leptin mutation) Physiological : pregnancy post menopausal women Endocrine disorders: hypothyroidism Cushing's syndrome PCOS Metabolic disorders: type II diabetes
Leptin Secreted by adipocytes Function: regulate energy intake /expenditure Mechanism: adequate fat deposit
leptin secretion
inhibit Neuropeptide – Y
reduce [email protected]
Assessment of obesity Body mass index (BMI) BMI: weight (kg) height (m2) Waist circumference Waist – Hip ratio
Biochemical alterations
Hyperglycemia Dyslipidemia Cholesterol: increased TAG: increased Hyperinsulinemia
Metabolic syndrome (syndrome X)
Components Obesity Diabetes mellitus Hypertension Dyslipidemia Insulin resistance
Protein – Energy Malnutrition
Causes: 1) poor intake (neglect child) 2) maternal malnutrition 3) infections 4) diarrhea 5) early weaning
Types of PEM
Kwashiorkor deficiency of protein with adequate intake of
calorie
Age: 1 – 5 years
Marasmus
deficiency of both calorie and protein
Age: < [email protected]
Biochemical alterations
Plasma albumin: reduced (< 2 g/dl) glucose: reduced potassium: reduced magnesium: reduced Fatty liver reduced lipoprotein synthesis IgG: increased
Solve this 4 yrs child come with retarded growth and pedal edema,skin and hair discoloration.on enquiry by doctor child was on breast milk up to 1.5 years of age and for 2and half years she was on rice and dal . Lab data showed low albumin1.Probable diagnosis 2.Cause for the oedema 3.Prevention ?
Treatment calories: 150 – 200 kcal / kg body weight protein: 3 – 4 gm / kg body weight vegetable protein: milk protein = 3:1 (pea nut / Bengal gram)
Total Parenteral nutrition (TPN)
Feeding a person intravenously, bypassing the usual process of eating and digestion
Indications GIT disorders: malabsorption prolonged diarrhea intestinal obstruction malnutrition coma burns
Nutrient solution is infused through large vein.
Contains glucose, amino acids, electrolytes, minerals (except iron), lipids & vitamins
Complications Infection Pulmonary embolism Fatty liver
Assessment of Nutritional status
Clinical assessment Useful in severe forms of PEM P/E: skin, hair, eyes Anthropometric assessment height, weight, BMI, Waist / Hip skin fold thickness Dietary assessment assess calorie / protein content
Laboratory assessment
Biochemical parameters Serum proteins, Creatinine, hydroxyproline
potassium / magnesium
Hematological parameters Hb, iron, vitamin levels
Microbiology Parasites
Diet prescription: principles
Ideal body weight (for height = 153 cm) male: 48 kg female: 45 kg Calculate calorie requirement Calculate protein requirement Diet should contain adequate proximate
principles [carb: prot: fat = 60: 20 : 20]
Calories: 2000 kcal Carbohydrate: 350 g Protein: 60 g Fat: 35 g Calcium: 400 mg Iron: 25 mg
Diet in diabetes
Calorie distribution breakfast: 15% mid morning snack: 5% lunch: 30% tea: 10% dinner: 35% bed time snack: 5%
Carbohydrates: 55 – 65% Sweet / refined carbohydrates are avoided Leafy vegetables are increased Fiber: 25 – 35 gm / day Protein: 12 – 16% (soy protein: 20 gm/day) Fat: < 30% SFA: < 10% MUFA: 12 – 15% PUFA: < 10% Cholesterol: < 200g/day
Diet in cardiovascular disease
Cholesterol lowering diet similar to diabetes diet SFA < 7% (avoid palm oil, coconut oil) Milk with low fat preferred Hypertension low sodium diet (<6 gm/day) increase intake of vegetables / fruits
Diet in Renal failure
Maintain fluid and electrolyte balance 1) Acute renal failure 2) Chronic renal failure 3) Dialysis
Acute renal failure
Water intake = urine out put + 500 ml Protein: 0.4 – 0.5 g / kg body wt Sodium and potassium are restricted
Chronic renal failure
Total calories: > 35 kcal/day Protein: 0.6 – 0.7 g/kg body wt Sodium: 1 – 3 g/day Potassium: 40 – 70 mmol /L Magnesium: 200 – 300 mg/day Fiber: 20 – 25 g/day
Food fortification (enrichment)
It is the process of adding micronutrients to food
Criteria 1) to replace nutrients lost during production 2) to act as public health intervention Eg: a) salt fortified with iodine b) Vanaspathi fortified with vitamin A / D
Food additives
non-nutritive substance added deliberately to any food product to improve its color, texture, flavor or shelf life
Eg: a) vinegar b) antioxidants c) coloring agents d) flavor enhancers
Food adulteration
The presence of harmful, unpalatable, or otherwise objectionable foreign substances in food
Eg: Common Salt White powdered stone
Honey Water
Ice Cream Washing Powder
Sugar Chalk
Milk Water
Food toxins
Agents which are present naturally / produced by living organisms that contaminates food
Causes food poisoning Classification Natural toxins: endogenous exogenous Synthetic toxins
Natural toxins
Endogenous source toxin source effects 1. glucosinolates cabbage goitre 2. cyanogens sweet potato neuropathy 3. solanine potato headache Exogenous source Aflatoxins: contaminate grains / peanut causes hepatic disease / encephalopathy
Synthetic toxins
acquired during food processing and storage Eg: nitrosamines ethylene dioxide trichloroethylene
Food additives
Non food substance to food intentionally
Ancient limemango
Salt, spices preserving
Newer Chemicals to increase taste , color, shell life
classification Category I Category II
SafeColor, preservation, flavour, acidity
Health hazardousIncidentalDuring packing, processing, farming, environment [email protected]
Safety in food additivesAdditives Use Safety
olestra Fat replacement G I
saccharine sweetener Ca Urinary bladder
sulphite Dough container Asthma
Sorbital/hexital Gum sweetener diarrhea
aspartame Artificial sweetener
Monosodium glutamate taste hypertension
Sodium nitrate antimicrobial methemoglobenemia
Food adulteration NeurolathyrismBeta oxalyl aminoalanine
1. Vitamin – c2. Soaking pulse in boiling water 2hrs1. Parboiling2. Baning the crop
Aflatoxin
Mycotoxin (mycotoxin aspergillus flavus,A.parasiticus)
Improper storage nuts and grains
Hepatocellular ca, infantile cirrhosis
Moisture should be <10%
Ergot Bajra, rye, wheat, sorgum During harvesting
infection by ergot fungus nausea, vomiting ,giddiness.
gangrene
Epidemic dropsy
Mustard oil with argemone oil
Toxic alkaloid-sanguinarine
Interfere with oxidation pyruvateNitric acid test for argemone oilPaper chromotography
Common adulterantsCereals (rice,wheat) Mud, grits, soap stonesDal Coal tar dye, khesari dalTurmeric powder Lead chromateDhania powder Cow dungPepper Papaya seedChillipowder Brick powderTea dust Tamarid husk, date huskGhee vanaspathiEdible oil Mineral oilasafoetida Sand, resin, gum
Prevention of food adulteration act,1954
Minimum imprisonment 6 months Grevious hurt (320) life imprisonment
Central food lab:Kolcutta, mysore, ghaziabad and pune
• Must be able write what are SDA with its significance?• Must be able to calculate energy requirement of man with different physical
activity?• Must be able write about glycemic index with examples and its relevance in
clinical • Must be able write about Dietary fibres & its beneficial in health and diseases• Must be able to define balance diet and mention the basic principle in
prescribing a diet• Must be able to list Nutritional functions of lipids? • Must be able to list essential fatty acids • Must be able to list Nutritional functions of protein? • Must be able to say what is of complete proteins?• Must be able to say what is Nitrogen balance? • Must be able to list the condition for negative and positive balance? • Must be able to say what is Protein energy malnutrition? Types? Differences?• Must be able to say what is TPN? When it is indicated and the complications
