Components of Food and Deficiency Diseases
NCERT Class 6 • Science • Chapter "Components of Food" | NCERT Class 12 • Biology • Chapters on human health
Components of Food and Deficiency Diseases
Food supplies the body with energy, with material for growth and repair, and with substances that protect it from disease. These come as five main nutrients plus water and roughage, and a diet that supplies all of them in the right proportion is a balanced diet.
The Nutrients and Their Roles
- Carbohydrates are the main source of energy and come from cereals, potato, sugar and fruit.
- Fats give more energy per gram than carbohydrates and also store energy; they come from oil, ghee, butter and nuts.
- Proteins build and repair the body and are called body building foods; they come from pulses, milk, egg, fish, meat and soyabean.
- Vitamins and minerals are needed in small quantity but protect the body and keep processes running, so they are protective foods.
- Water transports substances, regulates temperature and removes waste.
- Roughage or dietary fibre is not digested but helps move food through the intestine and prevents constipation.
- Iodine test detects starch and turns blue black; copper sulphate with caustic soda detects protein and turns violet; a translucent oil patch on paper detects fat.
Deficiency Diseases
- Vitamin A deficiency causes poor vision and night blindness.
- Vitamin B1 deficiency causes beriberi with weak muscles and low energy.
- Vitamin C deficiency causes scurvy, with bleeding gums and slow healing of wounds.
- Vitamin D deficiency causes rickets in children and soft bones in adults.
- Calcium deficiency causes weak bones and teeth, while iron deficiency causes anaemia with weakness and fatigue.
- Iodine deficiency causes goitre, a swelling in the neck, which is why iodised salt is promoted.
- Protein energy malnutrition causes kwashiorkor and marasmus in young children.
| Nutrient | Deficiency Disease | Common Sign |
|---|---|---|
| Vitamin A | Night blindness | Poor vision in dim light |
| Vitamin C | Scurvy | Bleeding gums |
| Vitamin D | Rickets | Weak bent bones |
| Iron | Anaemia | Weakness and pallor |
| Iodine | Goitre | Swelling in the neck |
Balanced diet — a diet that contains all the nutrients along with water and roughage in the right proportion.
Hindi me samjhein
विटामिन और खनिज कम मात्रा में चाहिए पर इनके बिना शरीर की प्रक्रियाएं रुक जाती हैं, इसीलिए इन्हें रक्षात्मक भोजन कहते हैं। रूक्षांश पचता नहीं फिर भी कब्ज रोकता है।
Exam me kaise aata hai
- Deficiency of vitamin C causes — scurvy
- Deficiency of iodine causes — goitre
- Deficiency of iron causes — anaemia
- Which nutrient is called the body building food — protein
UPSC/State PSC ke liye
- Iodine deficiency is tackled through salt fortification because salt is consumed by everyone in small regular amounts, which makes it an ideal carrier.
- Anaemia is widespread among women and children, which is why iron and folic acid supplements are given through public health programmes.
Yahan confuse hote hain
✗ Vitamins give energy | Vitamins protect and regulate; carbohydrates and fats give energy | ✓
✗ Roughage is useless because it is not digested | Roughage prevents constipation and is essential | ✓
✗ Scurvy is caused by vitamin D deficiency | Scurvy comes from vitamin C deficiency | ✓
Ek nazar me
- Carbohydrates and fats give energy; proteins build the body.
- Vitamins and minerals protect; water and roughage are also essential.
- Vitamin A for vision, C for gums, D for bones.
- Iron deficiency gives anaemia and iodine deficiency gives goitre.