Nutrition and Public Health

Overview

Nutrition is a critical component of public health and a high-yield chapter for NEET PG PSM. Questions are frequently asked on Protein Energy Malnutrition (PEM), vitamin deficiencies, BMI classification, National Nutrition Mission, and macronutrients/micronutrients. This chapter integrates well with maternal and child health, health programs, and epidemiology.

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Balanced Diet and Macronutrients

Definition of Balanced Diet

A balanced diet provides all essential nutrients in adequate proportions to meet the body’s nutritional requirements while maintaining optimal health.

Components of a Balanced Diet

Component	Proportion of Total Calories	Sources
Carbohydrates	60-70%	Cereals, millets, pulses, fruits, vegetables
Proteins	10-15%	Pulses, milk, eggs, fish, meat, legumes
Fats	20-30%	Oil, ghee, butter, nuts, seeds
Fiber	25-30 g/day	Whole grains, fruits, vegetables
Water	2-3 liters/day	Fluids, fruits, vegetables

Macronutrients

Carbohydrates

• Primary energy source — 4 kcal/gram
• Classification:
  • Simple carbohydrates (monosaccharides, disaccharides) — sugars, sweets
  • Complex carbohydrates (polysaccharides) — cereals, pulses, vegetables
• Functions: Energy production, glycogen storage, sparing protein
• Requirements: 300-500 g/day for adults

Proteins

• Building blocks of body — 4 kcal/gram
• Classification by amino acid content:
  • Complete proteins — contain all essential amino acids (egg, milk, meat, fish)
  • Incomplete proteins — lack one or more essential amino acids (pulses, cereals)
• Functions: Growth, repair, enzyme synthesis, immunity, hemoglobin
• Requirements: 1 g/kg/day for adults; higher in pregnancy/lactation
• Protein quality: BV (Biological Value) — Egg > Milk > Meat > Pulses

Fats

• Concentrated energy source — 9 kcal/gram
• Classification:
  • Saturated fats — solid at room temperature (ghee, butter, coconut oil)
  • Unsaturated fats — oils (mustard, groundnut, sunflower)
  • Trans fats — partially hydrogenated oils (harmful)
• Functions: Energy storage, hormone synthesis, vitamin absorption, cell membrane structure
• Requirements: 20-30 g/day visible fats; PUFA (polyunsaturated) preferred
• Essential fatty acids: Linoleic acid (ω-6), Linolenic acid (ω-3)

NEET PG Tip: Visible fat requirement in India: 30 g/day for adult male, 20 g/day for adult female

Micronutrients

Vitamins and minerals required in small quantities but essential for metabolic processes.

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Protein Energy Malnutrition (PEM)

PEM is the most common form of nutritional deficiency in India, especially among children under 5 years. It results from inadequate protein and calorie intake.

Classification of PEM

PEM
├── Marasmus (能量不足)
│   └── Severe calorie deficiency with preserved protein intake
├── Kwashiorkor (蛋白质不足)
│   └── Severe protein deficiency with adequate calorie intake
└── Marasmic-Kwashiorkor
    └── Both severe protein and calorie deficiency

Marasmus

Clinical features:

• Severe wasting (loss of subcutaneous fat and muscle)
• “Old man” appearance — aged face, prominent ribs
• Flag sign — alternating bands of light and dark hair (due to protein deficiency)
• Growth retardation — weight <<< expected for age
• Normal appetite (distinguishes from kwashiorkor)
• No edema
• Subcutaneous fat virtually absent
• Irritability and weakness

Biochemical findings:

• Low serum albumin (but less severe than kwashiorkor)
• Normal hair changes

Kwashiorkor

Clinical features:

• Bilateral pitting edema (hallmark — ankle edema, then generalized)
• Nutritional dermatoses — flaky paint appearance, hyperpigmentation, desquamation
• Hair changes — flag sign, sparse, thin, easily pluckable
• Hepatomegaly (fatty liver due to impaired lipoprotein synthesis)
• Apathy, irritability, anorexia
• Moon face (facial edema)
• Muscle wasting (though subcutaneous fat may be present)

Biochemical findings:

• Low serum albumin (<2.5 g/dL) — hallmark
• Low serum transferrin
• Low total protein

Differences Between Marasmus and Kwashiorkar

Feature	Marasmus	Kwashiorkor
Deficiency	Calorie deficiency	Protein deficiency
Edema	Absent	Present
Serum albumin	Low-moderate	Very low
Fat loss	Severe (no subcutaneous fat)	Variable (preserved or lost)
Hair changes	Less prominent	Prominent (flag sign)
Mental changes	Irritable	Apathetic, miserable
Appetite	Normal/good	Poor
Liver	Normal	Fatty liver

Memory Aid: Marasmus = Meal Missing (calorie deficiency)
Kwashiorkor = K-Protein (protein deficiency with edema)

Management of PEM

Principle	Approach
Treat infections	Broad-spectrum antibiotics
Correct electrolyte imbalance	Oral rehydration, electrolytes
Gradual feeding	Start with milk-based diets, advance slowly
High protein	1.5-2 g/kg/day
High calories	150-200 kcal/kg/day
Monitor	Weight gain, edema, appetite
Vitamin supplementation	Especially Vitamin A, B-complex, folate

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Vitamin Deficiencies

Fat-Soluble Vitamins (A, D, E, K)

Vitamin A (Retinol)

Feature	Details
Functions	Vision (rhodopsin), epithelial maintenance, immunity, reproduction
Sources	Liver, egg yolk, dairy, fortified oils; β-carotene in carrots, papaya, green leafy vegetables
Deficiency	Night blindness → Xerophthalmia → Bitot’s spots → Keratomalacia
Treatment	200,000 IU retinol orally (WHO protocol)

Xerophthalmia classification (WHO):

• XN — Night blindness
• X1A — Conjunctival xerosis
• X1B — Bitot’s spots
• X2 — Corneal xerosis
• X3A — Corneal ulcer (<1/3 cornea)
• X3B — Corneal ulcer (≥1/3 cornea)
• XS — Scars from previous keratomalacia

NEET PG Memory Aid: Bitot’s spots = Foamy, silvery-gray spots on temporal conjunctiva — pathognomonic of Vitamin A deficiency

Vitamin D (Calciferol)

Feature	Details
Functions	Calcium and phosphorus absorption, bone mineralization
Sources	Sunlight (UVB converts 7-dehydrocholesterol to cholecalciferol), fish liver oils, fortified milk
Deficiency	Rickets (children), Osteomalacia (adults), Hypocalcemic tetany
Treatment	Cholecalciferol 60,000 IU/week for 8 weeks + maintenance

Rickets features:

• Frontal bossing, parietal bossing
• Rachitic rosary (costochondral beading)
• Harrison’s sulcus
• Pigeon chest
• Delayed fontanelle closure
• Bow legs (genu varum) or knock knees (genu valgum)
• Dental abnormalities

Vitamin K

Feature	Details
Functions	Synthesis of clotting factors (II, VII, IX, X), protein C and S
Sources	Green leafy vegetables, bacterial synthesis in gut
Deficiency	Bleeding disorders (hemorrhagic disease of newborn)
Treatment	Phytomenadione (Vitamin K1) 1 mg IM at birth (prophylaxis)

Hemorrhagic Disease of Newborn:

• Occurs in first week of life
• Due to deficient Vitamin K-dependent clotting factors
• Prevented by Vitamin K injection at birth

Vitamin E (Tocopherol)

• Antioxidant, protects cell membranes
• Deficiency: Hemolytic anemia, neuromuscular problems
• Rare in humans

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Water-Soluble Vitamins

Vitamin B1 (Thiamine)

Feature	Details
Functions	Carbohydrate metabolism, nerve function
Sources	Whole grains, pulses, nuts, pork, yeast
Deficiency	Beriberi (wet: cardiac; dry: neurological), Wernicke-Korsakoff syndrome

Wet Beriberi:

• High-output cardiac failure
• Peripheral edema
• Cardiomegaly

Dry Beriberi:

• Peripheral neuropathy (symmetrical, distal)
• Wrist drop, foot drop
• Sensory and motor deficits

Wernicke Encephalopathy:

• Classic triad: Confusion, ataxia, ophthalmoplegia
• Due to thiamine deficiency (common in chronic alcoholism)

Vitamin B2 (Riboflavin)

• Deficiency: Cheilosis (angular stomatitis), glossitis, seborrheic dermatitis, normocytic anemia
• Sources: Milk, eggs, liver, green vegetables

Vitamin B3 (Niacin)

• Deficiency: Pellagra — Dermatitis, Diarrhea, Dementia (3 Ds)
• Sources: Meat, fish, peanuts, fortified cereals
• Also synthesized from tryptophan

Vitamin B6 (Pyridoxine)

• Deficiency: Peripheral neuropathy, sideroblastic anemia
• Required for neurotransmitter synthesis

Vitamin B12 (Cobalamin)

Feature	Details
Functions	DNA synthesis, nerve myelination, RBC maturation
Deficiency	Megaloblastic anemia, subacute combined degeneration of cord
Sources	Animal products (liver, meat, eggs, dairy)
Causes of deficiency	Pernicious anemia (intrinsic factor antibodies), vegan diet, malabsorption

Folic Acid

Feature	Details
Functions	DNA synthesis, RBC maturation
Deficiency	Megaloblastic anemia, neural tube defects (spina bifida)
Sources	Green leafy vegetables, liver, legumes
Prevention	Folic acid supplementation in pregnancy (400 μg/day)

Vitamin C (Ascorbic Acid)

Feature	Details
Functions	Collagen synthesis, wound healing, iron absorption, antioxidant
Sources	Citrus fruits, amla, guava, tomatoes, green vegetables
Deficiency	Scurvy — bleeding gums, petechiae, poor wound healing, joint pain
Treatment	Ascorbic acid 1-2 g/day

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Mineral Deficiencies

Iron Deficiency

Feature	Details
Functions	Hemoglobin synthesis, oxygen transport, enzyme systems
Sources	Red meat, liver, eggs, green leafy vegetables, jaggery
Deficiency	Microcytic hypochromic anemia, pica, koilonychia (spoon-shaped nails)
Treatment	Oral iron (ferrous sulfate 60 mg elemental iron 3x/day)
Prophylaxis	IFA (Iron Folic Acid) tablets in pregnancy, school children

NEET PG Tip: India has the highest prevalence of iron deficiency anemia among women and children globally.

Iodine Deficiency

Feature	Details
Functions	Synthesis of thyroid hormones (T3, T4)
Sources	Iodized salt, sea fish, seafood
Deficiency	Goiter, Hypothyroidism, Cretinism (irreversible)
Prevention	Universal Salt Iodization (USI) — mandatory in India since 1983

Iodine Deficiency Disorders (IDD):

• Goiter (enlarged thyroid)
• Hypothyroidism — fatigue, weight gain, cold intolerance
• Neurological cretinism — mental retardation, deaf-mutism, spasticity
• Myxedematous cretinism — dwarfism, mental deficiency
• Fetal loss — miscarriage, stillbirth

NEET PG Memory Aid: Iodine deficiency → IQ loss (Impairs brain development)

Calcium Deficiency

Feature	Details
Functions	Bone and teeth formation, muscle contraction, nerve transmission
Sources	Milk, dairy, green leafy vegetables, small fish (with bones)
Deficiency	Osteoporosis, rickets, osteomalacia, tetany (hypocalcemia)
Requirements	600 mg/day (ICMR); 1000 mg/day in pregnancy/lactation

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National Nutrition Mission (NNM) / POSHAN Abhiyaan

Overview

POSHAN Abhiyaan (Prime Minister’s Overarching Scheme for Holistic Nourishment) was launched in 2018 to improve nutritional outcomes for children, adolescents, pregnant women, and lactating mothers.

Key Components

Component	Description
Jan Andolan	Community mobilization and behavioral change communication
ICDS-Common Application Software (ICDS-CAS)	Digital tracking of beneficiaries
Mother’s Absolute Affection (MAA)	Breastfeeding support program
National Iron Plus Initiative	Anemia screening and treatment
National Vitamin D Plus Initiative	Vitamin D supplementation
Nutrition Resource Platform	Technical support and training

Targets

• Reduce low birth weight by 2% per year
• Reduce anemia in children, adolescents, and women
• Reduce stunting in children under 6 years
• Promote breastfeeding (early initiation, exclusive breastfeeding for 6 months)

POSHAN 2.0 / Mission POSHAN 2.0

• Merged multiple nutrition programs
• Focus on dietary diversification, nutrition education, and supplementary nutrition

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BMI and Obesity Classification

Body Mass Index (BMI)

BMI = Weight (kg) / Height (m²)

Classification	BMI (kg/m²)	WHO Category
Underweight	<18.5	Grade 1 thinness
Normal weight	18.5-24.9	Normal
Overweight	25.0-29.9	Pre-obese
Obese Class I	30.0-34.9	Moderate obesity
Obese Class II	35.0-39.9	Severe obesity
Obese Class III	≥40.0	Very severe/morbid obesity

WHO Asian Indian Classification

Indian guidelines have lower cutoffs due to higher body fat at lower BMI:

Category	BMI (kg/m²)
Underweight	<18.0
Normal	18.0-22.9
Overweight	23.0-24.9
Obese	≥25.0

NEET PG Tip: Indians develop metabolic complications at lower BMI compared to Western populations. The waist circumference criteria for metabolic syndrome in Indians: >90 cm (men), >80 cm (women).

Waist-to-Hip Ratio (WHR)

• More accurate than BMI for central obesity
• Men: >0.90 is high risk
• Women: >0.85 is high risk

Obesity-related Complications

• Type 2 Diabetes Mellitus
• Hypertension
• Dyslipidemia
• Coronary Artery Disease
• Stroke
• Osteoarthritis
• Obstructive sleep apnea
• Cancers (breast, colon, endometrial)
• Psychological/social issues

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Food Safety and Adulteration

Food Safety and Standards Act (FSSA), 2006

The FSSA 2006 is India’s comprehensive food safety law that:

• Sets standards for food articles
• Regulates manufacture, storage, distribution, and sale
• Creates FSSAI (Food Safety and Standards Authority of India) as the regulatory body
• Makes food safety compliance mandatory for all food businesses

Common Food Adulterants

Food Item	Adulterant	Health Effect
Milk	Water, urea, formalin, melamine	Kidney damage, cancer
Ghee/Butter	Vanaspati (margarine), animal fat	Cardiovascular disease
Honey	Sugar syrup, jaggery	Nil major harm
Chilli powder	Brick dust, red dye	Carcinogenic
Turmeric	Chalk powder, yellow dye	Nil major harm
Coffee powder	Chicory, tamarind seeds	Nil major harm
Black pepper	Papaya seeds	Nil major harm

Prevention of Food Adulteration (PFA) Act

• Establishes maximum limits for contaminants, preservatives, and food colors
• Defines food standards for various commodities
• Prohibits sale of adulterated or misbranded food

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NEET PG Exam Tips

High-Yield Points

1. Kwashiorkor = protein deficiency with edema and low albumin
2. Marasmus = calorie deficiency with wasting but no edema
3. Bitot’s spots = pathognomonic for Vitamin A deficiency
4. Pellagra = 3 Ds — Dermatitis, Diarrhea, Dementia (B3 deficiency)
5. Scurvy = Vitamin C deficiency — bleeding gums, poor wound healing
6. Beriberi = Vitamin B1 deficiency — cardiac (wet) or neurological (dry)
7. IDD = Iodine Deficiency Disorders — goiter, cretinism
8. IDA = microcytic hypochromic anemia — pica, koilonychia
9. Indian BMI cutoffs — overweight ≥23, obese ≥25 (lower than WHO)
10. POSHAN Abhiyaan — launched 2018, targets anemia, stunting, LBW
11. FSSAI — food safety regulatory body in India
12. Protein quality — Egg has highest BV (Biological Value)
13. Essential fatty acids — Linoleic acid (ω-6), Linolenic acid (ω-3)
14. Vitamin K deficiency → Hemorrhagic disease of newborn (prophylaxis: 1 mg IM at birth)

Question Patterns

• “Bilateral edema + low albumin + flaky paint skin” → Kwashiorkor
• “Wasting + old man face + no edema” → Marasmus
• “Foamy white spots on conjunctiva” → Bitot’s spots → Vitamin A deficiency
• “Angular stomatitis + glossitis” → Riboflavin (B2) deficiency
• “Who classification of BMI for Asian Indians: overweight at BMI ≥?” → 23*
• “Prevention of neural tube defects” → Folic acid supplementation in pregnancy*

Memory Mnemonics

Vitamins soluble in fat: A D E K — All DeKeApples (A, D, E, K are fat-soluble)

Pellagra 3 Ds: Dermatitis, Diarrhea, Dementia (think of a person who went Nuts — Niacin deficiency)

Kwashiorkor features: Protin deficiency, Edema, Appetite loss, Malnutrition, Skin changes (PEAMS)

Marasmus features: Severe wasting, Muscle loss, Normal albumin, Old man face, Useful appetite (SMNOU)

IDD prevention: USI = Universal Salt Iodization

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Summary Table

Deficiency	Disease	Key Features	Prevention/Treatment
Vitamin A	Xerophthalmia	Night blindness → Bitot’s spots → Keratomalacia	200,000 IU retinol
Vitamin D	Rickets	Rachitic rosary, bow legs, frontal bossing	Cholecalciferol 60,000 IU
Vitamin K	Hemorrhagic disease of newborn	Bleeding in first week	1 mg Vitamin K IM at birth
Vitamin B1	Beriberi	Wet: cardiac failure; Dry: neuropathy	Thiamine supplementation
Vitamin B3	Pellagra	Dermatitis, Diarrhea, Dementia	Niacin supplementation
Vitamin C	Scurvy	Bleeding gums, poor wound healing	Ascorbic acid 1-2 g/day
Iron	Microcytic anemia	Fatigue, pica, koilonychia	IFA tablets
Iodine	Goiter, Cretinism	Enlarged thyroid, mental retardation	Universal Salt Iodization
Protein/Calorie	Marasmus/Kwashiorkor	Wasting vs Edema	Nutritional rehabilitation

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Chapter: Nutrition and Public Health | Subject: PSM | Exam: NEET PG