Definition and types of vegetarian diet
The vegetarian diet is generally referred to as a dietary practice which consists of plants as the major food source and excludes most or all meat, offal and animal products. Vegetarian diets can be categorised as the following four categories:
- Lacto-ovo-vegetarian diet: A diet which excludes all animal products with the exception of eggs and dairy products.
- Ovo-vegetarian diet: A diet which excludes all animal and dairy products with the exception of eggs.
- Lacto-vegetarian diet: A diet which excludes all eggs and animal products with the exception of dairy products.
- Strict vegetarian diet (Vegan): A diet which excludes all eggs, dairy products, meat, offal and food products of animal origin such as honey and bird's nest.
What kind of health benefits does a plant-based diet offer?
Plants are mostly rich in dietary fibre and low in fat and energy. None of them contains cholesterol. Thus they help prevent constipation and increase our sense of fullness without adding too much burden to our weight and cholesterol level. Fruit, vegetables and legumes are also excellent sources of antioxidants and phytochemicals which can strengthen the immunity and reduce risks of chronic diseases such as hypertension, heart disease and diabetes. A vegetarian diet, however, does not guarantee optimal health unless balanced nutrition and a healthy lifestyle are adopted in our daily life.
What is a balanced vegetarian diet?
Vegetarians should follow the basic guidelines for “balanced diet” to assure adequate nutrient intake:
- Grains: A significant amount of dietary fibre and minerals could be lost during the manufacturing process of refined grain products such as white rice and white bread. Vegetarians are recommended to choose unrefined grain products as much as possible, such as brown rice, oatmeal, wholemeal bread and fortified whole wheat breakfast cereals.
- Vegetables and fruit: Eat a variety of fruit and vegetables of different colours in order to get various vitamins and nutrients. Avoid overcooking, which can lead to nutrient loss.
- Milk and alternatives: Lacto-vegetarians should consume an appropriate amount of low-fat milk or dairy products to ensure an adequate intake of protein and calcium.
- Protein group: Protein can be obtained from a variety of nuts, seeds, legumes and soy products. Ovo-vegetarians can also get high quality protein from eggs.
- Fat/oil, salt and sugar: Choose healthy vegetable oils. Use oils and condiments only in small amount.
Major nutritional challenges for vegetarians
- Protein: Since the quality and absorbability of protein from plant sources are less optimal than that of meat and milk (and their alternatives), vegetarians are recommended to eat an adequate amount and different types of nuts, seeds, legumes and soy products to attain balanced nutrition.
- Vitamin B12: Eggs and dairy products are both food sources of vitamin B12. However, no plants have been proven to be a safe and reliable source of vitamin B12. Strict vegetarians are recommended to consume products that fortified with vitamin B12 (such as soy milk and cereals) and seek a physician's advice on vitamin B12 supplement.
- Calcium and vitamin D: Dairy products are good sources of these essential nutrients for lacto-vegetarians. Ovo- and strict vegetarians, however, should obtain calcium from firm tofu, calcium-fortified soy milk, green leafy vegetables such as Chinese flowering cabbage and Chinese kale, etc. Adequate exposure to sunlight can stimulate the production of vitamin D in the skin and prevent bone loss.
- Iron: An adequate amount of legumes, black ear fungus, iron-fortified cereals and wholemeal bread should be consumed to prevent iron deficiency, which is common among vegetarians. Foods that are rich in vitamin C (such as tomatoes, broccoli and oranges) can be eaten together to aid iron absorption.
- Zinc: Sources of zinc include whole grains, brown rice, legumes, tofu, nuts and seeds.
How to make vegetarian dishes healthy and tasty?
A significant amount of oils and condiments are often added to vegetarian dishes for better taste and increased satiety. However, excessive intake of such will be harmful to health in the long run. Vegetarians should note the following cooking tips to prevent excessive intake of fat and salt:
- Instead of stir-frying and deep-frying, use low-fat cooking methods such as steaming, stewing, braising and boiling.
- Use a variety of healthy vegetable oils, such as corn oil, canola oil, olive oil and peanut oil. Avoid coconut oil, palm oil and margarine in solid form which pose a negative impact on your blood cholesterol level.
- Make your dishes attractive and tasty with a wide range of fresh ingredients. Gourds, mushrooms, seaweeds, soy products (including tofu, dried soybean sheet and dried soybean curd), fresh fruits, dried fruits and small quantity of nuts and seeds can all add nice and natural flavour to your vegetarian recipes.
- Natural spices such as Chinese prickly ash, star anise and cinnamon are good alternatives to condiments and sauces with high fat or salt content.
- Reduce the amount of oil used by making cornstarch sauce for your dishes and by cooking with non-sticky pans.
Vegetarians with special nutritional needs
People who eat vegetarian diets may be at risk of deficiency of certain nutrients, such as protein, vitamin B12, iron, calcium and vitamin D. Before following a vegetarian diet, children, adolescents, pregnant women, lactating mothers, elderly persons and people with chronic diseases are advised to consult their physicians and dietitians for an individualised diet plan in order to meet their special nutritional needs.