NUTRITION

1. NUTRITION

2. Nutrition • is the science of dealing with the utilization of food by the body processes which transforms food into body tissues and energy • Nutrients are necessary for normal functions of the body. • The energy is provided by three classes of nutrients: fats, carbohydrates, proteins and they are called the macronutrients

3. . Vitamins and minerals, are called the micronutrients Both macronutrients and micronutrients in optimal amounts are needed to maintain health and prevent disease in adults.

5. Balance diet • A balanced diet is one which contains all the required nutrients in adequate amounts without exceeding the safe limits. • Its a diet that provides all the 6 nutrients : carbohydrates, proteins, fats, minerals , vitamins , water in proper amounts and proportions to maintain good health.

6. Construction of a balanced diet: • Selection of foods : The food selected should be economic, locally available, palatable and easily digestible. Foods should be selected from (cereal group, Protein/Meat group, Fruits & Vegetable group, Milk group, Sugar, Fats and Oil Group). Balanced diet should contain calories from carbohydrate, proteins and fats in the ratio 60:20:20 .

7. 2.Calories: Calorie requirement depends on the height, weight and physical activity of the individual . On an average it is taken as 30-35 kcal per kg of ideal body weight. 3. Protein requirement: 1g per kg body weight for adults and 2g per kg body weight for children. During pregnancy and lactation protein requirement is about 2.5 g per kg body weight

8. Dietary goals ( recommendations for a balanced diet ) • BD must be low in saturated and trans fats , cholesterol, added sugars , salt. • Water : 1.5 lit to 2 liter day • Adequate Fibers and antioxidants • Protein to be 10 to 15 %

9. Junk foods must be avoided. • Main food :75% energy from cereals • Milk : 100ml in a day • 1 medium sized fruit and green leafy vegetables • No alcohol, smoking, or tobacco consumption.

10. ICMR recommended Balanced Diet

11. Role of proteins in diet (nutritional role of proteins) • Required for : Dietary proteins are essential for • growth and tissue repair. They are the only sources for essential amino acids. Recommended protein allowance 1g/ kg bodyweight provision of essential amino acids . 2. provision of energy (10% total energy requirement of body ) 3. provision of nitrogen , phosphorous and sulfur.

12. Nitrogen balance or Nitrogen equillibrium : Dietary protein is almost an exclusive source of nitrogen to the body. Nitrogen balance = dietary intake of protein nitrogen (16% of the weight of protein) and measuring the daily excretion of nitrogen. In a normal healthy adult the dietary intake (I) = the daily loss through urine (U) feces (F) and sweat(S). I= U + F+ S N intake = N output.

13. Negative nitrogen balance: Nitrogen intake < Nitrogen output. Seen in starvation, protein energy malnutrition , wasting diseases like tuberculosis and illness . Positive nitrogen balance: Nitrogen intake > Nitrogen output • 1. Growth: During active growth, a state of positive nitrogen balance exists. • 2. Pregnancy: due to growth of fetus. • 3. Convalescence; A person recovering after an illness or surgery will be in positive nitrogen balance.

14. Hormones: Growth hormones, insulin, and androgens promote positive nitrogen balance • while corticosteroids cause negative nitrogen balance.

15. Quality of dietary proteins: Is determined by … • Essential amino acid content • Digestibility .

16. Dietary sources of proteins : A) Animal sources : contains all essential amino acids in sufficient amounts and have good digestibility . Called as complete proteins/ first class proteins. E.g. egg, milk ,meat , fish etc. B) vegetable sources : lack some essential amino acids. Incomplete proteins/ class II proteins.They have lower digestibility because they have tough cell walls preventing proper digestion . E.g. cereals and pulses Soy proteins is only complete plant protein.

17. Nutritional classification of proteins 1) complete proteins: contains all essential amino acids in sufficient amounts and good digestibility. E g. Egg, milk ,meat. 2) partially complete proteins :they partially lack one or more essential amino acids. They promote moderate growth. E.g. vegetable proteins . 3) Incomplete proteins: They completely lack one or more essential amino acids. They do not promote growth at all. E.g Zein of corn and gelatin of animal source.

18. Limiting amino acids : The essential amino acid that is deficient in a food protein is called as the limiting amino acid for that dietary source. E.g. pulses are deficient in methionine and cereals are deficient in lysine.

19. Complementary action of proteins (complementary proteins) : Consuming mixed diet will solve problem of limiting amino acids. i.e combination of foods. This combination of different vegetables will form first class protein. This is called Mutual supplementation of proteins.

21. Indices for Assessment of Quality of Dietary Proteins The following are some of the indices used to assess the nutritional value of proteins. • 1. Biological value of protein • 2. Net protein utilization • 3. Protein efficiency ratio • 4. Chemical score • 5. Essential amino acid content

22. 1) Biological value of protein (BPV) Definition : it is the ratio between the amounts of nitrogen retained to the amount of nitrogen absorbed BVP= Nitrogen retained X 100 Nitrogen absorbed • It reflects the essential amino acid content of the proteins but not digestibility

23. 2) Net protein utilization (NPU) Definition : ration between the amounts of nitrogen retained to the amount of nitrogen intake . NPU= Nitrogen retained X 100 Nitrogen intake • It accounts for both essential amino acid content and digestibility of proteins .

24. Foods Net Protein Utilization Egg - 100 % Milk - 100 Meat - 92 Fruits - 76 Vegetables - 73 Legumes - 70 Cereals - 59

25. 3) Digestible coefficient (DC): It is the percentage of food nitrogen which is absorbed from elementary canal. DC = Food nitrogen – (fecal nitrogen – metabolic fecal nitrogen ) X 100 Importance : legumes and seeds have lower DC than milk and egg proteins. Cooking improves DC of plant proteins.

26. Chemical score : Ratio between the content of most limiting amino acid in a test protein to the content of the same limiting amino acid in egg protein.(reference protein ) Chemical score = mg of limiting amino acid /g of protein X 100mg of the same amino acid /g of egg protein

27. Biomedical importance Nutritional disorders may be due to deficiency or excess of nutrients. Common nutritional disorders are: • Obesity • Malnutrition • Vitamin deficiency disorders Obesity is a disorder of chronic calorie excess characterized by an accumulation of excess body fat. Malnutrion is the most wide spread nutritional problem in developing country affecting children. At one end of spectrum of malnutrition is marasmus and at the other end of the spectrum is kwashiorkor

28. Protein Deficiencies • Adults : Protein deficiency in adults leads to loss of body weight, anemia, susceptibility to infection , general lethargy, edema , and delay in wound healing. • Children : Deficiencies of proteins mainly cause Protein Energy Malnutrition.

29. Spectrum of PEM in different age groups:

30. Protein Energy Malnutrition • Most common nutritional disorder of the developing countries including INDIA. • KWASHIORKOR and MARASMUS are two extreme forms of PEM.

31. Kwashiorkor • Definition : the word kwashiorkor is derived from(tribe ) Ghana , which means “ the sickness the older one gets when the next child is born “ • Kwashiorkor is caused due to protein deficiency in the presence of adequate calorie /energy. • Causes: Children between 1-5 years ,child weaned from mothers breast milk to carbohydrate rich food deficient in proteins.

32. Kwashiorkor • Edema • Pot (swollen ) belly • Fatty liver (enlarged liver due to fat accumulation) • Skin lesions • Discoloured hair ( due to lack of melanin formation ) • Anorexia • Hypoalbuminemia ( decreased serum levels of albumin )

33. Edema due to hypoalbuminemia Flaky paint dermatosis Flag sign in hair

34. MARASMUS Definition : Marasmus ( means wasting ) is characterized by predominant energy deficiency and a lesser protein deficiency . ( primary calorie deficiency and secondary protein deficiency ) Causes: Seen in children less than 1 year when mother’s milk is weaned and replaced by a low cost native cereal diet, which is poor in both calorie and protein . ( so marasmus is also called protein calorie malnutrition )

35. MARASMUS Symptoms • Extreme muscle wasting ( emaciation ) • Weakness • Anemia • Diarrhea • Face of the patient shows apathy( no interest) • Marasmic patients do not show edema and decreased serum albumin in kwashiorkor .

36. Chest to head circumference ratio is reduced Generalized Emaciation of fat but prominently seen at buttocks, buccal pad etc. Irritable

37. Difference b/w kwashiorkor & marasmus: Kwashiorkor Marasmus

38. Kwashiorkor • S. Protein: low (↓ albumin & β-globulin) • A:G ratio: reversed • Edema • Total Body Lipid: high • Fatty liver in characteristic feature. • Anorexia, less glycogen store in fatty liver  Hypoglycemia Marasmus • S. Protein: reduced but not so low as kwashiorkor • A:G ratio: maintained • Muscle wasting • Total Body Lipid: low • Fatty liver not common • Reduced intake, less glycogen & fat reserve  Hypoglycemia

39. Management of PEM: • Resuscitation. • Routine Treatment. • Diet management.

40. Resuscitation Prevent & Correct… • Hypothermia: warm atmosphere • Hypoglycemia: IV glucose, frequent feeding • Dehydration: IV fluids, ReSoMal, ORS • Electrolyte disturbances: • Micronutrient deficiency: multivitamin & mineral supplements. Treat infection if present

41. Diet management • Started initially as stated in resuscitation. • Addition of ghee, jaggery, oils can make food energy dense. Regular diet: • For Kwashiorkor  150kcal/kg/day • For Marasmus  200kcal/kg/day • Proteins  4gm/kg/day • Use of seasonal fruits & vegetables should be encouraged.

42. obesity • Most prevalent nutritional disorder. Obesity index : or modern expression Body Mass Index : W/H2 height in meters square. Disease related to obesity : Syndrome X: metabolic syndrome ( insulin resistance, hyperglycemia, hyperlipidemia) • Obesity leads to Diabetes Mellitus, CAD, hypertension. Treatment : • Lifestyle modification, Atkins diet : low carbohydrate ketogenic high protein diet for losing weight.

43. Other nutritional disorder include : • Rickets • Osteomalacia, • Iron Deficiency anemia • Night blindness • Beriberi, • Pellagra, • Pernicious Anemia , • Scurvy etc.

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