Thursday, May 20, 2010

What is Therapeutic Diets and Modifications of diets?

What is Therapeutic Diets and Modifications of diets?

Diet therapy deals with modifications necessary in the diet in the treatment of different diseases.  This is necessary as the metabolism of the individual changes in different diseases with respect to one or more nutrients.  Some examples are: inefficient utilization of carbohydrates in diabetes mellitus, inability of the kidney to excrete sodium chloride in nephritis, increased production and inefficient elimination of uric acid in gout and increase in energy metabolism and in the catabolism of tissue proteins in fever.  The simplest modification of diets is in the treatment of allergy where the food or foods responsible for the allergic reactions are eliminated.

Modifications in diets in other diseases may involve changes in different constituents such as:

·         Balanced diets omitting condiments and spices.
·         Low fiber or high fiber diets.
·         High protein or low protein diets.
·         High fat or low far diets.
·         High carbohydrate or low carbohydrate diets.
·         High calorie or low calorie diets.
·         Low sodium diets and
·         Low purine diets.

In case, the patient cannot consume food orally, then administration of nutrients through parental route or through nasogastric tube is essential to avoid starvation and loss of proteins and other nutrients from the tissues. The types of changes required in the diets in different diseases are briefly discussed below:

  • Modifications in carbohydrate content – High carbohydrate diet may be indicated in Addison’s disease, various diseases of the liver and in pre-operative conditions.  Hypoglycemia may be present in Addison’s disease, while in the other two conditions, adequate glycogen storage is of considerable value in the therapy of these conditions.  Restricted carbohydrate diet is essential in the treatment of diabetes mellitus.
  • Modifications in calorie content – Diets with increased calorie value are for the treatment of patients who are markedly underweight and also for patients with increased calorie requirements as in fever, infections, mal-absorption and hyperthyroidism.  Low calorie diets are used for the treatment of obesity, cardio-vascular disease, acute uremia and hepatic coma.
  • Modifications in protein contentHigh protein diets with restriction in other nutrients are prescribed in a variety of diseases such as protein calorie malnutrition, cirrhosis of liver, peptic ulcer, nephrosis and celiac diseases.  Low protein or complete withdrawal of proteins may be necessary in hepatic coma, acute uremia, etc.
  • Modifications in fat content – Moderately high fat diet are used in the treatment of severe under nutrition.  Restricted or low fat diet may be necessary in the treatment of steatorrihoea, mal-absorption syndrome and diseases of the liver.
  • Modifications in mineral content – High calcium diet is essential in the treatment of rickets and osteomalacia, while a diet restricted in calcium and phosphate is desirable in renal calculi.  Sodium restricted diets are essential in the treatment of cardiac failure and hypertension.  Restriction in sodium chloride intake is essential in diseases of the kidneys.
  • Modifications in vitamin content – Increase in the content of vitamins can be easily achieved by the addition of synthetic vitamins.  This is essential as most of the therapeutic diets may be partially lacking in one or more vitamins.

  • Modifications in fiber content – Diets rich in fiber are prescribed for the treatment of constipation, while low fiber diets are essential in the treatment of several gastrointestinal disorders such as peptic ulcer, ulcerative colitis, celiac diseases, diarrhea's and dysentery.
  • Modifications in other constituents – Diets low in purine content are prescribed in the treatment of gout, while diets low in oxalic acid and purines are prescribed in renal calculi.
  • Modifications in diet consistency – The most important are the liquid diets used in oral feeding and nasogastric feeding. The basis of such diets is milk to which soluble carbohydrates such as sucrose, glucose and dextrimaltose and emulsified fats are added to increase their calorific value.

Whats is Lathyrism? Symptoms and Preventions of Lathyrism

Lathyrism, is a crippling disease characterized by paralysis of the leg muscles occurring mostly in adults consuming large quantities of the seeds of L-sativus(Lathyrus sativus) or other lathyrus species over long periods.  In India, the disease occurs in Madhya Pradesh, Bihar, and Uttar Pradesh.  The disease has also been reported to occur in Spain, Algeria and occasionally in certain parts of France and Italy where lathyrus peas are consumed by the people. 

Signs and Symptoms of Lathyrism
Acton has described four stages of the development of the disease in human beings.  The first stage is characterized by weakness of the lower limbs with spasticity of leg muscles so that movement at the ankle and knee joints is restricted and painful.  In the second stage, flexion of the knee is more marked and there is a certain amount of inversion of food with a tendency to talk on toes.  In the third stage, the symptoms described above become more marked and the subject can walk only with the help of crutches or sticks.  In the fourth stage, the knee becomes completely flexed and erect posture and walking becomes impossible.  There is atrophy of the thigh and leg muscles.

Identification of toxic factors in the lathyrus and the vicia species

Two types of lathyrism have been reported to occur in animals and human beings, viz., osteolathyrism where pathological changes occur in the bones resulting in skeletal deformities and neurolathyrism in which the muscles of the legs are paralyzed sometimes resulting in convulsions and death in severe cases.  Different species of lathyrus cause one or the other type of disease though sometimes both types may be caused by the same species.

Lathyrus sativus seeds have been implicated for a long time as responsible for lathyrism in some parts of India.  This disease is mainly of the neurological type.  The main neurotoxic substance was established as B-oxalylamino alanine.  This compound causes nervous derangement in young chicks but rats and mice are not appreciably affected.  This might be the reason for many of the earlier contradictory reports regarding the toxicity of the seeds of L-sativus when different test animals were employed.

There is now conclusive evidence that excessive consumption of L-sativus seeds is the cause of the high incidence of lathyrism in certain parts of India.  Although the harmful effects of L-sativus have been realized for some years, effective steps for the prevention of the disease have not so far been taken by the government.  There are three possible approaches for the eradication of the disease:

  • Treatment of the seed by leaching out the toxic factors in hot water both on home scale and factory scale.
  • Education of the public on the dangers of consuming untreated L-sativus and
  • Cultivation of other pulses in place of L-sativus.
Removal of toxic factors by leaching in water:  Acton was the first worker to point out that L-sativus seeds soaked in three changes of water are non-toxic.  Later workers have confirmed the above observation that the toxic factors present in L-sativus could be leached out in water.  It is evident that the toxic factors can be removed by
(1) Cooking the whole seed and decuticled seed in excess of water and draining the water and
(2) Steeping the whole seed or decuticled seed in hot water for 4 to 5 hours and rejecting the soak water.  The later process can be carried out on industrial scale and the resulting detoxified dhal could be sold to the people through ration shops and cooperative stores.

Public Awareness – There is urgent need for educating the public on the dangers of consuming of L-sativus seeds.  This should be done through leaflets distributed in schools, hospitals and municipality centers pointing out the dangers of consuming the untreated L-sativus seeds and the need for the removal of the toxin factors from the seed and dhal by steeping in hot water and rejecting the soak water.

Cultivation of other pulses in place of L-sativus – The governments of different states where lathyrism is prevalent should, if necessary, by enactment of law, enforce the cultivation of other pulses commonly grown in the region in place of L-sativus.

Tuesday, May 4, 2010

Effect of Excess and Loss of Water on Water Balance

Effect of Excess Water intake on Water Balance in the Body

If two liters of water are taken, the water is distributed rapidly throughout the body.  The kidney responds to the increased water intake after about 15-30 minutes.  The flow of urine rises from the normal value 50 ml per hour to its peak of 1500 ml per hour.  The extra water is excreted by the kidney within three hours.  The excess urine output may be almost equal to the water ingested. In tropical climate, a greater part of the ingested water is lost in the sweat.

Effects of Water Deprivation/Loss on Water Balance

Water is being constantly lost from the human body in the form of urine, sweat, faeces and expired air.  If corresponding amounts of water are not ingested, water depletion occurs in the body leading to change in the body fluids.  A reduction in volume of the extra cellular fluid and intracellular fluid takes place.  The urine output is reduced.  There is a rapid decrease in body weight and a state of dehydration of the cells occurs.  After a few days, a decrease in plasma volume occurs which will reduce cardiac output and lead to circulatory failure.  An adult who has lost 5-10 liters of water from the body will be seriously ill and death will occur when the water loss from the body is about 15 liters.

Body Water Balance, Intake and Outlet/loss of Body Water.?

Body Water Balance, Intake and Outlet/loss of Body Water.

Water is the main constituent of the body, about 60-70% of the total Body Weight consists of Water.  The water content of Soft Tissues ranges from 70-80%, while that of bone about 20 percent approximately.

Body Water is distributed as follows:
  • Intracellular water (ICW), which present Inside the cells of tissue
  • Extra cellular water (ECW), are Outside the tissue cells
The Extra cellular water (ECW) is further subdivided into:
  • Water in blood plasma.
  • Interstitial water – water in tissue space.
  • Lymph in the lymphatic vessels.
Intake and Outlet/loss of Water.
Water is taken in food and also as drinking water.  In addition, water is formed in the tissues by the oxidation of hydrogen present in proteins, carbohydrates and fats. 

Water intake varies widely depending on the climate; as drinking water about 1500-5000 ml and in food 1000-2000 ml.
Water is lost continuously from the body in the following ways: 
  • Through kidney as Urine.
  • Through insensible perspiration and as sweat.
  • Through the lungs in the expired air.
  • Through the large intestines in the faeces.
  • In lactating women in the milk.

Body Water Loss varies depending on the climate: in urine, about 100-1500 ml, through skin 800-5200 ml, through lungs 400 ml and in faeces 100-200 ml.  In a normal individual, the water intake is approximately equal to water lost from the body and the water content of the body is maintained fairly constant.

Effect of Excess and Loss of Water on Water Balance?

Required Nutrients during Lactation Period / Lactating Mothers.

Not only during the Pregnancy period there is a need of various Nutrients but also during lactation period(Milk Production and Secretion period).  Nutritional requirements should be increased due to the milk secreted by mother is to feed the new born baby.  Milk output varies in the lactating mother.

The Required Nutrients during Lactation Period are given under:

·  It has been expected that the efficiency of conversion of diet calories to human milk calories is only 60 percent.  On this basis, production of 420 milk calories will need 700 diet calories. 

· For the production of 7.2 grams of milk proteins, about 14.4 grams of dietary proteins will be required. 

· The quantity of calcium present in 600 ml of human milk is 205 mg.  Since the retention of dietary calcium in lactating women is about 30 percent, the additional dietary calcium requirement will be about 700 mg per day.

· The iron content of 600 ml of human milk is about 0.72 mg.  Since only about 20 percent of the dietary iron is retained in lactating women, it will be essential to provide about 3.6 mg of extra iron in the diet.

· The quantity of vitamin A is present in 600 ml of human milk is 300Mg(Microgram).  It is recommended that an additional allowance of 400 Mg(Microgram)of vitamin A is required. 

· Additional calorie requirements during lactation are 700 K calories.  The extra requirements of nicotinic acid, riboflavin and thiamine to meet the needs of extra calories will be 0.3 mg thiamine, 0.4 mg of riboflavin and 4.6 mg of nicotinic acid per day. 

· The quantity of ascorbic acid present in 600 ml of human milk will vary from 15-30 mg.  It is recommended that an additional allowance of 30 mg of ascorbic acid. 

· The quantities of folic acid and B12 vitamin present in 600 ml of human milk will be 6 Mg(Microgram) and 0.14 Mg(Microgram) respectively.  It is recommended that an additional allowances of 50 Mg(Microgram) of folic acid and 0.5 Mg(Microgram) if B12 vitamin.

Pregnant Women's Nutritional Needs/Requirement?

Pregnant Women's Nutritional Needs/Requirement?

Even though Pregnancy is an normal process of physiology, they increase considerably the Nutritional requirements of the Pregnant Women/Mother.  Due to frequent vomiting and loss of appetite during the early months of Pregnancy, the food intake is normally reduced.  Further, additional Nutrients are required for the growth of Fetus.  The baby weighing about 3.2 kg at birth will contain about 500 grams of protein, 30 grams of calcium, and 0.4 grams of iron and varying quantities of different vitamins.

The requirements of various Nutrients during Pregnancy are given below:

The total calorie cost of supplying and maintaining the Fetus has been estimated to be about 40,000 KCalories.  Since the greater part of calories will be required mostly during the second and third trimesters, the additional requirements will workout to 200 K calories per day. 

Available evidence would indicate about 910 grams of Proteins are deposited in the Fetus and maternal tissues during Pregnancy.  The average daily increment is estimated to be about 5 grams during the last six months of Pregnancy.  These will workout to 10 grams additional Proteins in terms of dietary Proteins. 

It has been expected that about 30 grams of calcium is deposited in the Fetus during Pregnancy.  This will workout to about 150 mg of extra calcium during the last six months of Pregnancy.  Since dietary calcium is utilized to the extent of about 25 percent in Pregnancy, the additional requirements will workout to 600 mg in terms of dietary calcium. 

It has been expected that about 540 mg Iron are found in the Fetus and maternal tissues.  This will workout to about 2 to 3 mg iron per day during the last six months of Pregnancy.  Since, the iron from diets is utilized only to an extent of about 20 percent in pregnant women, the extra dietary iron requirements will be about 10 to 15 mg per day.

The quantity of vitamin A found in the liver of infant is about 5400-7200 Mg(Microgram) of retinol and this will workout to about 25-35 Mg(Microgram) additional retinol per day.  Since the additional requirements are small as compared with the daily requirements of 750 Mg(Microgram)for a normal woman. 

Small quantities of Nicotinic acid, Riboflavin and Thiamine vitamins are present in the tissues of new born infants.  The extra calorie allowance of 300 K calories per day for pregnant women will need an increase in the requirements of these vitamins.

Small amounts of folic acid and B12 vitamin are present in the tissues of new born infants. 

Small amounts of Ascorbic acid are present in the tissues of new born infants.  Normal women would meet the additional requirements of 50 mg of Ascorbic acid during Pregnancy. 

Required Nutrients during Lactation Period / Lactating Mothers.

How to reduce over weight? Preventions while reducing weight?

Treatment/ How to reduce over weight/Obesity?

Since obesity is caused by excess calorie intake and lack of exercise, the main principles involved in the treatment are:

  • Reduced Calorie intake, and
  • Increased Physical Activity
Reduced diet:
The aim of reducing calorie intake is to produce a calorie deficiency in the body which will result in utilization of fat stored in the adipose tissue to meet the calorie needs.  A reducing diet should normally provide only about half the daily calorie requirements.  Reducing diets at varying costs for adults providing 1100 and 1300 K calories are given.

Increase Exercise:
Moderate exercise helps to burn up more energy and prevent increase in body weight in normal persons consuming diets just adequate in calories.  For example, walking three miles a day will require 300 K calories.

Weight maintenance diets:
The composition of weight maintenance diets for adults at varying costs providing 1500 and 1800 K calories is given.  Consumption of these diets by adults will help to maintain the body weight at constant level.

Prevention for Obesity
Prevention of obesity is by avoidance of eating frequent and excessive foods which contains rich in high calories such as sweets, nuts, and fried foods.
By doing moderate exercise you can prevent from obesity.
You should maintain body weight by consuming normal level of calorie.
Nutrition education for mothers as well as children helps to prevent from incidence of obesity.

How is Obesity Measured and Problem caused due to Obesity?

How is Obesity Measured and Problem caused due to Obesity?

How is Obesity Measured/Assessed?
Obesity can be assessed by 
(i) Body Weight, 
(ii) Estimation of total body fat
(iii) Skin-fold measurements and 
(iv) But Nowadays the Body Bass Index (BMI) is the simplier way to measure the obesity. 
A person whose body weight is higher than normal by 20 percent may be considered as obese. 

Complications of Obesity / Obesity Implications / Problem caused due to obesity.
Obesity leads to the development of several complications such as:
  • Physical disability
  • Metabolic disorders
  • Cardiac disorders
  • Proneness to accidents
  • Low life expectancy
Obese persons suffer more often from metabolic disorders such as diabetes mellitus, atherosclerosis and heart diseases.  They meet with accidents more frequently.  The life expectancy is also reduced in view of the above hazards.

What is Obesity and What are the Factors Contributing to Obesity?

Obesity is the condition in which a person has overweight because of deposition of fat in the adipose tissue.  The common cause of obesity is consumption of food in excess of requirements.  Excess food consumed is converted into fat and stored in the adipose tissues.  Obesity is very common among people living in western countries and among the higher income groups in India and other developing countries.

What are the Factors Contributing to Obesity.
Age and Sex:
There is no age limit for occurrence of obesity.  It occurs either for male or female.  The incidence is higher in persons who lead sedentary lives.

Economic status/ Corporate People:
Obesity is more common among the higher income groups as they consume excess food and do less physical work than the low income groups.

Physical Activity:
Obesity occurs rarely among persons who do hard work physically.  It is very common in those who lead sedentary lives.  With the extensive use of transport facilities and mechanization of industry, the proportion of people who lead sedentary lives has been increasing.

Proneness to obesity:
Some individuals are more prone to develop obesity than others.  Recent investigations have shown that these individuals have usually large proportion of adipose tissue cells as compared with normal persons.  These cells are filled with fat when excess food is consumed.

Physiological regulation of food intake
Food intake is controlled by the central nervous system.  It is initiated by hunger and inhibited by the feeling of fullness of the stomach.  Food intake is markedly influenced by the feeding centre and satiety centre present in the hypothalamus region in the brain.  In experimental animals, if the feeding centre is destroyed, the animals lose appetite, refuse to eat and finally die of starvation.  If the society is destroyed the animals eat voraciously and become obese in a short time.

How is Obesity Measured and Problem caused due to Obesity?

Whats is Malnutrition? How to Prevent Malnutrition?

An adequate diet should contain liberal amounts of protein-rich and protective foods and should supply all the dietary essentials in the required amounts.  Dietary surveys carried out in western countries have shown that the diets contain large amounts of protein-rich and protein foods such as milk, eggs, meat and fish and provide all the Nutrients in adequate amounts.  

The rate of growth of children and the nutritional status of the population are very good.  Studies carried out in United Kingdom and United States of America have shown that the quality of diets consumed by the people during the period 1910-1960 have been steadily improving and consequently the growth rate of children indicating thereby that the diets have been adequate for promoting maximum growth in children.  On the other hand, the diets consumed by a large majority of the population in the developing countries of Asia, Africa and Latin America, are based mainly on Energy Yielding Foods and contain only small amounts of Protective Rich Foods.  Such diets are deficient in proteins, certain vitamins and minerals.  

A fair section of the population does not get enough food to eat and their diets are deficient in calories also.  The rate of growth of children in the developing countries is poor.  The children are malnourished, emaciated and stunted.  The incidence of protein calorie malnutrition, clinical signs and symptoms due to vitamin A deficiency and anemia (Red Blood Cells- deficiency) are quite high among weaned infants and pre-school children.

Prevention of Malnutrition
The problem of overcoming malnutrition and improving the nutritional status of the vulnerable sections of the population has been engaging the attention of nutritionists.  Studies carried out in several nutrition research laboratories all over the world have shown that supplementation of the diets with extra cereals, legumes and green leafy vegetables or with processed food supplements based on cereals, oilseed meals and fortified with essential vitamins and minerals can help effectively to overcome malnutrition and improve the health and nutritional status of the population.  Recent developments have made it possible to manufacture vitamins synthetically on a large scale at low cost and use them for fortifying low cost food supplements and for the treatment of vitamin deficiency diseases.  By the application of the available knowledge, it is possible to eradicate malnutrition. 

Classification of Nutrients in Foods

Classification of Nutritional Foods

Since foods vary widely in their contents of various Nutrients, they have been broadly grouped under three heads from the nutritional point of view namely,

1) Body building foods
2) Energy-yielding foods and
3) Protective foods.  

These are briefly discussed below:

Energy yielding foods:
Rich in carbohydrates and Fat Foods are called Energy Yielding foods.  Cereals, tubers and roots, dried fruits, sugars and fats are included in this group.  Cereals contain, in addition, fair amounts of proteins, minerals and certain vitamins and form the important sources of the above nutrients in poor dietaries.

Body Building Foods:
Body Building Foods are those foods which are rich in proteins, Pulses, Milk, Meat, Oilseeds, Fish, Eggs and Nuts and lower Fat Oilseed Fours are included in the group of body building foods.

Protective Foods:
Protective Foods are those foods which are rich in Vitamins, Proteins, and Minerals.
Protective Foods are broadly divided/classified into 2 Groups: (a) Foods rich in Vitamins, Proteins, and Minerals with high biological value, for example, milk, eggs, and liver, and (b) Foods rich in certain specific vitamins and minerals only, for example, green leafy vegetables and fruits.

What are Nutrients and different types of Nutrients?

Studies carried out by many scientists have shown that foods contain several chemical constituents which are known as nutrients.  These chemical are which a organism need to develop its substance using its metabolism.  These are basically used in enrichment of body. 

What are the different types of Nutrients?
Proteins, Carbohydrates, Fats, Minerals, and Vitamins.

The importance of these nutrients is briefly discussed below:

What are Proteins and why are they Important/required?
Proteins are required for growth in children and maintenance of body weight in adults.  Proteins also provide energy to a small extent.  Proteins constitute about 25% of the body weight.  Body proteins are derived from the dietary proteins.  The body loses continuously some quantity of proteins and this loss has to be made up of simpler chemical substances known as amino-acids.  The amino-acid contents of proteins have been found to differ from one protein to another.  The nutritional value of proteins depends on their amino-acid contents.  As a result of studies carried out by several scientists, a large amount of information is available on the nutritive value of dietary proteins and the protein requirements of human beings.

What and why are Carbohydrates used?
Carbohydrates are the main sources of energy for doing work.  The carbohydrates commonly occurring in foods are starch, cane sugar, glucose, fructose and milk sugar.  About 50 to 70 percent of energy value in the average diet is provided by carbohydrates.  They are the cheapest source of energy.  Glucose derived from the digestion of carbohydrates is used as the main source of energy in the body.  Hence, the diets should contain adequate amounts of carbohydrates to meet a greater part of the energy needs.

What are the functions of fats and oils / How Fats and oil functions in the body?

Oils and fats serve mainly as the source of energy and they contain some essential nutrients like essential fatty acids and fat soluble vitamins.  Fat is essential for maintaining good health, as absence of fat leads to the development of a deficiency disease affecting the skin known as Phrynoderma.

Different types of Minerals?
The body contains about 24 minerals all of which are derived from the diet.  The important minerals are calcium, phosphorus, potassium, sodium, chloride, magnesium, iron, copper, iodine, cobalt, fluorine and zinc.  The minerals are essential for formation of various body functions, example, calcium and phosphorus for the formation of bones and teeth, sodium, potassium, chloride and phosphorus for maintaining water balance in the body, iron and copper for the formation of hemoglobin and iodine for the normal functioning of thyroid glands.  Diets should, therefore, provide adequate amounts of all the minerals.

What and how many types of Vitamins are there?
Studies carried out by several pioneers have shown that foods contain certain chemical substances in small amounts which are now called Vitamins.  About 17 different vitamins have so far been discovered.  All of them are essential for normal functioning of the human body.  Inadequate intake of vitamins will lead to the development of deficiency diseases.  Vitamins have been grouped under two heads: fat soluble vitamins such as vitamins A, D, E and K and water-soluble vitamins, example, vitamin B, riboflavin, niacin, pantothenic acid, folic acid, biotin, vitamin C and vitamin P.  A large amount of information is available on the functions of vitamins, vitamin content of foods and vitamin requirements.