The diet which meets all the metabolic requirements of the body is called a balanced diet. It contains all the food components in optimum proportion and quantity. Overnutrition and undernutrition lead to ill health.
   Deficiency nutrient: Fe
   Symptoms: Decrease in number of RBC and amount of Hb.
2. Megaloblastic anemia
  Deficiency nutrient: Folic acid (B9)
   Symptoms: Large, immature nucleated RBC in blood.
3. Pernicious anemia
   Deficiency nutrient: Cyanocobalamin
   Symptoms: Large, immature nucleated RBC without Hb
4. Night blindness
   Deficiency nutrient: Vitamin A
   Symptoms: Less rhodopsin in the rod cells leads to poor vision in dim light.
5. Xerophthalmia
   Deficiency nutrient: Vitamin A
   Symptoms: Keratinized ulcerated cornea leads to blindness especially in children.
6. Rickets (in children)
   Deficiency nutrient: Vitamin D
   Symptoms: Weak soft bones due to poor deposition of Ca and PO4 in the bones.
   Bending of long bones (bow leg), swelling on wrist, elbow etc.
7. Osteomalacia (in adults)
   Deficiency nutrient: Vitamin A
   Symptoms: Weak bones of vertebral column, deformed pelvis etc.
8. Beriberi
   Deficiency nutrient: Vitamin B1
   Symptoms: Numbness and weakness of limb muscles, paralysis, odema, cardiac failure etc.
9. Scuvy
   Deficiency nutrient: Vitamin C
   Symptoms: Fragile blood vessels, bleeding gums, loose teeth, delayed wound healing.
10. Marasmus
   Deficiency nutrient: Protein
   Symptoms: Emaciated body with thin limbs and prominent ribs, wrinkled skin, diarrhea etc.
11. Kwashiorkor
   Deficiency nutrient: Protein
    Symptoms: Wasting of muscles, protruded belly, oedema, diarrhea etc.
12. Pellagra
     Deficiency nutrient: Niacin (Nicotinamide)
    Symptoms: Thick pigmented skin, swollen lips etc.
    Excess nutrient: Saturated fats like butter, ghee, vegetable oils, meat, egg etc.
    Symptoms: High cholesterol level which deposits on the walls of blood vessels causing their stiffening, rise in blood, pressure, cardiac disorders.
14. Obesity
    Excess nutrient: Food with high calories such as sugar, honey, ghee
    Symptoms: Accumulation of fat in tissues. High blood pressure, cardiac disorders etc.
Nutritional disorders due to deficiency of dietary components
1. Anemia   Deficiency nutrient: Fe
   Symptoms: Decrease in number of RBC and amount of Hb.
2. Megaloblastic anemia
  Deficiency nutrient: Folic acid (B9)
   Symptoms: Large, immature nucleated RBC in blood.
3. Pernicious anemia
   Deficiency nutrient: Cyanocobalamin
   Symptoms: Large, immature nucleated RBC without Hb
4. Night blindness
   Deficiency nutrient: Vitamin A
   Symptoms: Less rhodopsin in the rod cells leads to poor vision in dim light.
5. Xerophthalmia
   Deficiency nutrient: Vitamin A
   Symptoms: Keratinized ulcerated cornea leads to blindness especially in children.
6. Rickets (in children)
   Deficiency nutrient: Vitamin D
   Symptoms: Weak soft bones due to poor deposition of Ca and PO4 in the bones.
   Bending of long bones (bow leg), swelling on wrist, elbow etc.
7. Osteomalacia (in adults)
   Deficiency nutrient: Vitamin A
   Symptoms: Weak bones of vertebral column, deformed pelvis etc.
8. Beriberi
   Deficiency nutrient: Vitamin B1
   Symptoms: Numbness and weakness of limb muscles, paralysis, odema, cardiac failure etc.
9. Scuvy
   Deficiency nutrient: Vitamin C
   Symptoms: Fragile blood vessels, bleeding gums, loose teeth, delayed wound healing.
10. Marasmus
   Deficiency nutrient: Protein
   Symptoms: Emaciated body with thin limbs and prominent ribs, wrinkled skin, diarrhea etc.
11. Kwashiorkor
   Deficiency nutrient: Protein
    Symptoms: Wasting of muscles, protruded belly, oedema, diarrhea etc.
12. Pellagra
     Deficiency nutrient: Niacin (Nicotinamide)
    Symptoms: Thick pigmented skin, swollen lips etc.
Nutritional disorders due to Overnutrition
13. Hyperchlesterolmia    Excess nutrient: Saturated fats like butter, ghee, vegetable oils, meat, egg etc.
    Symptoms: High cholesterol level which deposits on the walls of blood vessels causing their stiffening, rise in blood, pressure, cardiac disorders.
14. Obesity
    Excess nutrient: Food with high calories such as sugar, honey, ghee
    Symptoms: Accumulation of fat in tissues. High blood pressure, cardiac disorders etc.