Veggie diet can be healthy

PUBLISHED : Sunday, 06 April, 2008, 12:00am
UPDATED : Sunday, 06 April, 2008, 12:00am

This week T.C. Chu, 13

T.C. asks: Is a vegetarian diet healthy?

Wynnie says: Both omnivorous and vegetarian diets have potential health benefits as well as risks. Scientific studies have shown that vegetarians live longer and suffer less from heart disease, some cancers, hypertension and Type 2 diabetes.

This may be due to the diet alone, though many vegetarians are more health-conscious and so lead healthier lifestyles, such as doing more exercise and not smoking.

A vegetarian diet needs to be planned carefully, especially during teenage years when rapid growth and development take place. Special emphasis should be on obtaining adequate protein, iron, calcium and vitamin B12.

Cutting out meat or other animal products means you have to replace them with foods that have similar nutrition levels. For example, protein from animal sources contains all the amino acids (protein building blocks) that the body needs. Apart from soya, most plant proteins have a low content of one or more of the essential amino acids that we need.

Different amino acids are missing in different plant foods. Therefore, to ensure an adequate intake of essential amino acids, plant foods can be combined to provide high-quality protein. For example, complementary combinations include beans and rice or dhal and rice, beans on toast or a peanut butter sandwich. Eating a mixture of plant foods throughout the day will ensure your requirements for essential amino acids are met.

Vegetarians who drink milk and eat dairy products will have adequate intakes of calcium. However, vegans (vegetarians who don't take milk or other dairy products or fish) may lack calcium.

Although calcium can be found in green leafy vegetables and other plant foods, the bioavailability is reduced by the presence of compounds such as phytates and oxalates. These combine with calcium to form insoluble complexes, making calcium unavailable for absorption by the body. Vegans need to choose fortified products, for example, calcium-fortified soya milk, cereals or tofu processed with calcium sulphate.

Iron from animal products is easily absorbed by the body. While foods such as eggs, cereals, green vegetables and nuts contain iron, they are present in a form which is not properly absorbed by the body.

Vitamin B12 is only found in foods of animal origin. Hence, vegetarians need a supplement or foods fortified with vitamin B12, such as yeast extract, soya milk or breakfast cereals (check the labels).

If a vegetarian diet is well-balanced, it should provide all the nutrients needed by the body.

T.C.'s diary

Breakfast: Milk, egg and ham sandwich

Lunch: Noodles with beef and vegetables

Dinner: Vegetables, steak, fish and soup

Snacks: Chips

Exercise: Swimming