There are hundreds of thousands of diets are available in the world such as Atkins diet, medeterranean diet, vegetarian diet and raw food diet. Vegetarian diet is most common among Sri Lankan people. They choose to follow vegetarian diet for different purposes. Most are ethical concerns of animal and some are to promote their healthy life.
Vegetarian diet can be categorized as different types, such as lacto vegetarian, vegan, lacto ovo vegetarian etc. the vegan diet does not include any animal based foods. It includes only foods from plant sources like fruits, vegetables, legumes, pulses and grains. Lacto vegetarian diet includes food from plants and dairy products. Lacto ovo vegetarian diet includes eggs, dairy products and plant based foods.
Vegetarians must be aware about some nutritional concerns, if they consume optimal vegetarian diet also. A vegetarian diet need not be deficient in nutrients. However, the risk of getting nutrient deficiencies is high among vegetarian people compared with non vegetarian. They should consider about some nutrients such as protein, vitamin B12, essential fatty acids, iron vitamin D and Zn.
Adequate amount of protein in the diet is very important to provide all essential amino acids. Vegetarians have an incrased risk for protein deficiency because they eliminate certain high protein foods from their diet. Vegan avoids eating meat, poultry, fish, sea food and dairy products which are all high protein foods. Eating a wide variety of food such as soy-based foods, legumes, nuts, and whole grains although many plant based foods are not considered as complete protein. A complete protein is a high quality protein that contains all of the essential amino acids that required each day by body to build, repair and maintenance of cells. Soy protein has been shown to equal to protein of animal origin. Consumption of soy based foods such tofu, tempeh, soy based protein drinks, soymilk and soy yogurt can reduce the risk of protein deficiency
Iron deficiency also can be a nutrional problem in vegetarians, especially among women. The major function of iron is to transport oxygen to all of the organs, muscles and tissues in the body there are two forms of iron found in food. Haem iron and non-haem iron. Haem iron is the more readily absorbed form of iron found in meat, poultry and fish. Plant based foods contain high concentration of non-haem iron. It is not absorbed readily as haem iron. Vegetarians need to include plenty of iron rich foods in diet like dried beans, Spinach and dried fruits. It is better to combine iron rich foods with foods that enhance iron absorption and avoid foods that inhibit iron absorption. Citrus fruits, tomatoes, capsicum, broccoli, cabbage and spinach are good sources of vitamin C. It has been shown to enhance the absorption of the non haem iron found in plant foods. Vegetarians should try to avoid Regular tea, herbal teas such as red wine coffee. And cocoa at meal times because they contain tannins that reduces the absorption of non haem iron. For best absorption of iron calcium supplements should be avoided at the same time as eating iron rich foods
Vitamin B12 is a water soluble vitamin that comes naturally only from animal sources. Vitamin B12 works together with folate in the synthesis of DNA and RBC. It is also involved in the production of the myelin sheath around the nerves and the conduction of nerve impulses. Very low B12 intake can cause nerves and the conduction of nerve impulses. Very low B12 intake can cause nervous system damage and anemia. To avoid B12 deficiency, it is recommended to take B12 fortified foods or B12 supplements
Getting enough essential fatty acids may also be difficult in vegetarian diet. Essential fatty acids that body cannot produce it, but that should be obtain from food. They are important for the energy production and the production of various compounds in the body like eicosanoids. The two essential fatty acids are linoleic acid and alpha linolenic acid. Linoleic acid can be obtained from variety of vegetables. DHA and EPA are the forms of alpha linolenic acid, but the active form in the body is DHA that primarily found in animal foods. The plant form of alpha linolenic acid is insufficiently converted to DHA in the body. Supplementation of DHA is important for vegetarians to avoid DHA insufficiency
Vitamin D is found only in animal food sources. Vegans who don’t get much sunlight may need a supplementation. Getting enough calcium and vitamin D is important to keep bones strong. Vegan needs to eat lot of calcium rich foods like orange juice, soy milk, and calcium fortified breakfast cereals. Some leafy vegetables like spinach, some legumes and soybean products have relatively high concentrated calcium but that is not efficiently absorbed. It is affected by level of 0xalte and phytate in the diet which are inhibitors of calcium absorption thus decrease the amount of calcium the body can extract from plant foods.
So the vegetarian diet needs to include variety of food sources such as fruits, vegetables, legumes, nuts and seeds, soy products and whole grains. Vegetarian can get adequate nutrient from nonmeat sources, but vegans need to pay attention to get enough protein, iron, calcium, vitamin D, vitamin B12 and omega 3 fatty acids