Prof. Dr. Shyam P Lohani 

THE practice of vegetarianism started from 6th century B.C. from India, Greece and Italy. The concept had originated from the principle of not harming animals. Nowadays, there are a lot of options available in the supermarkets and eateries for people who primarily eat plant-based foods than in the past. People choose vegetarian diets for different reasons such as health, religious, and rights related to animal welfare.
Sub-groups
Becoming a vegetarian has become more accessible due to the growing number of vegetarian foods that are available in the market. Vegetarianism is defined as the practice of refraining from the consumption of meat (red meat, poultry, seafood, and the flesh of any other animal), and may also include abstention from by-products of animals processed for food (Wikipedia, 2019). However, there are different subgroups among vegetarians. Total vegetarians or vegans do not eat meat, poultry, and fish, any products derived from animals such as eggs, dairy products, honey, and gelatin. Lacto-Ovo vegetarians eat eggs and dairy products but refrain from meat, poultry or fish. Lacto-vegetarians avoid meat, fish, poultry, and eggs but eat dairy products. Ovo-vegetarians eat eggs but avoid other animal products. Some pesco-vegetarians eat fish but avoid other animal products. There are other terms such as pure vegetarians, strict vegetarians, and flexi-vegetarians.
An estimated 375 million people are vegetarians worldwide. The number of vegetarians has been increasing each year across the world. There may be several reasons why people are turning into a plant-based diet. Besides religious beliefs and love for animal welfare, mainly people are becoming vegetarians for health reasons and owing to the recommendation of health care providers. A growing number of people are becoming aware that plant-based foods that are based on whole grains, legumes, fruits, and vegetables with reduced consumption of meat and low intake of sugar, salt, and fat-based products are better for their body and healthy life. Only a few countries are promoting diet or food systems that are healthy, sustainable and delicious. The UN has called upon all the countries to move towards vegetarianism (UN, 2016).
The environmental impact of the livestock sector is enormous. An estimated 14.5 per cent of greenhouse gas emission is from the livestock sector and highly concentrated form of manure that causes environmental pollution and has a tremendous impact on the environment. The methane gas excreted by animals is said to be 30 times more potent than carbon dioxide as a greenhouse gas. There are numerous health benefits to being a vegetarian but the issue of being strict or total vegetarian also has raised debates and has gone through criticism. Vegetarian diets have lower saturated fats and higher fiber content than animal-based products. Vegetarian has a lower body mass index (BMI) than non-vegetarians. They have a lower level of bad cholesterol, low-density lipoprotein (LDL), therefore, they have lower chances of cardiovascular diseases. Studies have shown that vegetarians have lower chances of different types of cancer than non-vegetarian.
Vegetarians should give special attention to a few of the nutrients such as calcium and Vitamin D, Vitamin B12, omega 3 fatty acids, iron, zinc, and iodine for which prime source is animal-based food products. Calcium is essential for our strong teeth and bone health. Milk and dairy products are a great source of calcium which is needed as mentioned above. They should consider taking sufficient amounts of dark green vegetables to compensate for animal products to get those nutrients. However, calcium-enriched and fortified products like cereals, soy milk, soy yogurt, and tofu are good alternative foods for vegetarians. For sufficient Vitamin D needed for the body, vegetarians should take soy and rice milk, cereals and kinds of margarine besides enough direct sun exposure. People who have limited sun exposure may need to consider Vitamin D supplements also from selected plant sources. Vitamin B12 is found almost exclusively in animal products. Therefore, it can be difficult for a strict vegetarian to get enough B12. They, however, need to consider Vitamin supplements; vitamin-enriched cereals and fortified soy products to prevent Vitamin B12 deficiency. Proteins can be obtained from plant sources that include but not limited to soy products and meat substitutes, legumes, lentils, nuts, seeds, and whole grains.
The intake of fatty acids from canola oil, soy oil, walnuts, ground flaxseed, and soybeans is a good source of essential fatty acids but for omega 3 fatty acids, strict vegetarians should consider fortified products or supplements or both. The vegetarians should plan eating beans and peas, lentils, enriched cereals, whole grain products, dark leafy vegetables and dried fruits for sufficient iron needed for a healthy body and of course healthy life. Moreover, iron from plant source is not easily absorbable, the recommended intake for iron for vegetarians is nearly double than those needed for non-vegetarians. The foods rich in Vitamin C such as strawberry, citrus fruits, tomatoes, cabbage, and broccoli help absorb iron for people who are vegetarians. Like iron, zinc is not easily absorbed from available plant sources. Whole grains, soy products, legumes, nuts, and wheat germ are the main plant sources of zinc.
Risk of deficiency
The vegetarian also may not get a sufficient amount of iodine and may be at risk of deficiency of iodine and develop even a goiter. Also, foods such as soybeans, cruciferous vegetables, and sweet potatoes may promote a goiter in those people who are strict vegetarians. However, just one-fourth teaspoon of iodised salt per day provides a significant amount of iodine and might be sufficient for the iodine requirement of our body. Every people need to consider balanced food for a healthy life and if you are choosing to become vegetarian, you should always be cautious to get enough of the above nutrients for a healthy life and fit physical body. Being vegetarian is easy but people should be cautious while being a vegetarian.

(Prof. Lohani is the academic director of Nobel Health and Education Foundation and can be reached at lohanis@gmail.com)