There is much interest in the range of dietary practices followed by vegetarians, both in terms of the nutritional content of their diets and their health.
Parallel to this, there is also growing awareness on the potential benefits of plant-based diets. Even those who include meat in the diet are advised to eat more plant-derived foods.
Vegetarianism has become more popular in recent years, and a body of information is now emerging that provides an insight into the differences between those following an omnivorous diet (contains both animal and plant foods) and those following plant-based diets.
Despite the popular opinion that vegetarianism is a healthy option, there are some areas for concern. The nutritional status of an individual is at risk when any group of foods is regularly omitted from the diet, for whatever reason, whether it is an altruistic demand to avoid meat, or in response to an allergy to a particular food, such as cows’ milk or eggs.
Whatever the motive for avoiding a certain food group, care must be taken to ensure that the diet remains balanced and nutritionally complete to avoid any deficiencies and to ensure optimal nutritional status.
Who are vegetarians?
Vegetarians are people who consume plant-based foods as their major protein sources and exclude meat, poultry and fish.
The reasons cited for being vegetarian include ethical causes (including animal welfare); health concerns; sensory and taste preferences; religious reasons cost or as a reaction to food safety scares.
Vegetarians practice different degree of strictness depending on the beliefs of the individual or family. Some people eat animal products such as milk and eggs but not animal flesh.
Others eat plant foods only. A vegan is a person who eats only foods of plant origin.
A lactovegetarian eats plant foods plus milk and other dairy products. An ovovegetarian includes eggs as the only source of animal protein. An ovolactovegetarian consumes milk, dairy products and eggs in addition to plant foods.
Vegetarian diets can be healthy as long as the foods are selected and prepared appropriately. There is evidence that a well-planned vegetarian diet is nutritionally adequate, healthful and provides benefits for prevention of certain chronic diseases such as heart diseases.
Since vegetarian diets eliminate foods from animals, it is necessary to find substitutes for the nutrient-dense animal products. The general healthy eating principle also applies to vegetarian diets.
MIXTURE OF PLANT PROTEIN FOODS
The following is recommended:
Choose a variety of foods including whole grains, vegetables, fruits, legumes, nuts, seeds and if tolerated, dairy products and eggs can be included in the diet.
Minimise the intake of sweetened, fatty and heavily refined foods and select low fat dairy products to reduce saturated fat intake.
Vegetable protein foods contain fewer essential amino acids than animal proteins (meat, eggs, and dairy products).
Vegetarians must, therefore, eat larger and varied amounts of vegetables and cereals to compensate for the lower quality protein in vegetable foods.
It is recommended that they eat a mixture of plant protein foods such as soya beans and soya products, other beans, pulses, nuts and cereals to make up for the deficiencies of essential amino acids. Soya bean products are complete protein sources and should be included in the diet.
Complete proteins are those that contain all essential amino acids in proportions capable of promoting growth in the human body when they are the sole sources of proteins in the diet.
Other nutrients of concern are iron, calcium and vitamin B12. Sources of iron for vegetarian diets include beans, dark green vegetables, dried fruits and iron-fortified cereals or oats.
Vitamin C rich foods (like citrus fruits) should be included in each meal to enhance iron absorption and for prevention of anaemia.
For those who do not consume dairy products, intake of calcium would be impaired. It is advised that they choose beans (particularly soya and soya products), nuts, dark green vegetables, calcium-fortified food such as soya milk, juice or cereals to achieve an adequate intake.
Vitamin B12 deficiency is common for vegans. They are, therefore, advised to take supplements of this vitamin to prevent pernicious anaemia.
Vegetarians can use a variety of fresh and colourful ingredients, and vegetarian seasonings like herbs, spices and vegetable stock with different cooking methods to make their dishes nutritious, attractive and tasty.
The writer is based at the Department of Human Nutrition, Egerton University.