For proper growth and development, every organism requires an adequate amount of nutrients in proper proportion in their diet. If a person takes excessive nutrition (over nutrition) or deficient nutrition (under nutrition), it causes nutritional deficiency disorders. The nutritional deficiency of a nutrient for a long period causes the structural and functional disorders of some body parts. Such disorders caused by under nourishment are called deficiency diseases.
There are two types of nutritional disorders like over nutrition and under-nutrition. The under nutrition also called malnutrition, which is characterized by nutritional deficiency which may be both quantitative and qualitative. Over-nutrition causes obesity and hypercholesterolemia.
1. Disorder due to under- nutrition: The protein nutrient deficiency in the diet causes the protein-energy malnutrition(PEM). It is characterized by dietary deficiency of proteins and total food calories. Infants and young children are especially susceptible, as they need sufficient nutrients to grow and develop normally. Malnutrition reduces the ability to combat other illness and infection. Malnutrition is most common in most part of rural areas. Two most commonly occurring diseases of infants and children due to PEM in poor families are:
· Kwashiorkor
· Marasmus
I. Kwashiorkor : This is the disease caused by continued deficiency of proteins in diet. It was first reported from Africa but now it is prevalent in many parts of the world. It is one of the most commonly found deficiency diseases which mainly occurs in children among the age of 1 to 3 years, especially belonging to poor families. Generally, a child getting less than 1 gm protein per kg body weight per day suffers from this disease.
Causes- Main causes of Kwashiorkor are:
a. Prolonged breast feeding by the mothers having in adequate proteins in their diet.
b. Diet mainly containing carbohydrates and fats.
c. Late intake of supplementary food.
Symptoms- This disease is characterized by following symptoms:
Loss of appetite and reduced vigour, poor physical and mental growth, anemia, protruded belly and bulging of eyes, repeated diarrhea, darkening of skin, atrophy of muscles and oedema of hands, feet and face, increased sensitivity to infections.
II. Marasmus: it is also most commonly in children below one year of age. It is caused due to simultaneous deficiency of proteins and total food calories due to prolonged starvation.
Causes- Main causes of marasmus are:
a. Early replacement of mother’s milk by other foods deficient in proteins and calorific value.
b. Less spacing between the children.
Symptoms- it is characterized by- Shriveled appearance of child, extreme thinning of limbs (emaciation), ribs become prominent as the fat layer below the skin disappear, retarded physical and mental growth, skin becomes dry and wrinkled, digestive disorders and repeated diarrhoea.
2. Disorders due to over- nutrition
i. Obesity – this is very common nutritional disorder in which there is accumulation of excess body fat in the body. It is caused by ingestion of greater amount of food than can be utilized by the body for energy i.e. when “energy input exceeds energy output”. Obesity causes the development of a number of diseases such as cardiovascular diseases, gallstones, osteoarthritis, diabetes, etc.
ii. Hypercholesterolemia- it is caused due to excess intake of saturated fats like butter, ghee, vegetable oils, red meat and eggs. These foods increase tremendously the level of cholesterol in blood. These cholesterol get deposited on the walls of blood vessels that may cause the development of symptoms like high blood pressure, various cardiovascular disorders, etc.