Vegetarian diets exclude animal products and are practiced with differing degrees of restriction. When most people think of a vegetarian diet, they are referring to an ovolactovegetarian diet, which excludes meat. Vegan diets exclude all animal products, including dairy, honey, and eggs. Lacto-vegetarian diets include dairy but exclude meat and eggs.
Vegetarianism has been practiced throughout history for a variety of religious, cultural, philosophical, social, and economic reasons. Similarly, people have expressed concerns about animal welfare and the environmental, ethical, and proposed health benefits associated with the consumption of animals and animal-based products. Many individuals over the years have chosen to either exclude or reduce their consumption of animal meats and associated products. Many followers of certain religious faiths have similarly adopted differing degrees of vegetariantype eating patterns, including Buddhism, Jainism, and Hinduism.
Vegetarian eating patterns date back over hundreds of years. Famous vegetarians include Plato, Socrates, and Pythagoras. In the earlier stages of the vegetarian movement, there was a scarcity of evidence and knowledge to help support people in making the decision to adopt a vegetarian diet. Over the years, however, a wealth of evidence-based research has provided the public with information about how to ensure that dietary intake is balanced despite the exclusion of animal products. Research has also suggested health benefits associated with vegetarianism, such as reduced risk of disease.
In 2011, the U.S. Department of Agriculture released a new form of its dietary recommendations— MyPlate—which replaced the food pyramid. MyPlate recommendations are illustrated in the form of a dinner plate separated into four sections: fruits, vegetables, grains, and protein, with a side dish for dairy. The MyPlate recommendations can be adapted to reflect the dietary needs of lacto-vegetarians. Ensuring that substitute foods of similar nutritional value to meat and eggs are introduced will help achieve an adequate protein intake.
The grains section contains starchy carbohydrates and is relatively similar for both meat eaters and lactovegetarians. Foods include bread, cereals, rice, potatoes, yams, oats, corn, rye, millet, barley, quinoa, buckwheat, and cous cous. Egg-free pasta is available as a noodle or pasta substitute. Quinoa is a particularly good grain for lacto- and other types of vegetarians, because it is one of the few plant-based complete proteins. Complete proteins provide the body with all of the essential amino acids that it needs and are usually meat products.
Grains are usually low in fat and are good sources of energy, and whole grains are typically high in fiber. Fiber helps people feel full quickly and for longer, reducing the risk of snacking throughout the day. Fiber-containing foods also help to regulate bowel movements and reduce the risk of constipation. For optimum benefits, food from this food group should be included at each mealtime.
Fruits and vegetables are important to vegetarian diets. These foods provide essential vitamins and minerals—including vitamins A and C, folate, and fiber—that can help reduce the risk of cancer, stroke, and heart disease and contribute to the maintenance of general good health. The worldwide recommendations for fruit and vegetables vary somewhat, but most sources encourage a minimum of five portions of fruit and vegetables per day.
Foods in the protein section that are appropriate for lacto-vegetarian diets include pulses, lentils, vegetarian cheese, nuts, textured vegetable protein, meat substitutes, seeds, soy, and peas (including chickpeas). Protein is a very important nutrient because it makes up part of the structure of every cell in the body. There is a constant turnover of cells in the body, so an adequate supply of protein is essential for good health. Protein foods should not be the main source of fuel for the body; this should come from starchy carbohydrates. Someone consuming large intakes of protein and only small amounts of starchy carbohydrates will end up using protein as their main energy source, which will leave insufficient amounts to meet the daily protein needs of the body. People following a lacto-vegetarian diet should consult with a qualified doctor or registered dietitian if they are concerned about consuming too much protein.
Dairy products include milk, cheese, yogurt, fromage frais, and soy products. Even though lacto-vegetarian diets permit dairy products, some lacto-vegetarians may still choose to include some dairy-free options (such as soy-based products) as part of their dietary intake. It is important to note that soy-based products are typically low in calcium as compared to dairy foods, and individuals are encouraged to opt for brands that are fortified with calcium. Calcium is a mineral essential for healthy bones and teeth. Dairy foods are also a rich source of protein, energy, vitamin B2 (riboflavin), vitamin A, and vitamin B12.
A lacto-vegetarian diet is generally lower in fat and higher in both fiber and antioxidants than a meat-based diet. Much research suggests that individuals who adopt vegetarian eating patterns are less likely to suffer from obesity, coronary heart disease (CHD), high blood pressure, type 2 diabetes, certain nutrition-related cancers, and constipation. People who choose vegetarian diets tend to lead healthier lifestyles.
People wishing to adopt lacto-vegetarian eating habits need to know how to go about it safely. It is essential to ensure that foods excluded from the diet are replaced with suitable nutritional equivalents. Important nutrients such as iron are found primarily in meat and animal products, so vegetarians may risk vitamin and mineral deficiencies if they do not take steps to ensure that these needs are met.
Iron is essential for the formation of red blood cells, which carry oxygen to all parts of the body. A low body iron level can result in anemia. Iron from non-meat sources is referred to as nonheme iron, whereas iron from meat sources is heme iron. The body is able to absorb heme iron better than nonheme iron. Sources of nonheme iron include green leafy vegetables, pulses, wholemeal bread, fortified cereals, dried fruit, and nuts and seeds, including sesame, pumpkin, and sunflower seeds. Consuming vitamin C (such as in a glass of orange juice) with nonheme iron helps enhance the absorption of iron in the body.
The omega-3 essential fatty acids found in oily fish are found in vegetarian foods such as rapeseed (canola) oil, flaxseeds, and walnuts. Omega-3 fatty acids are thought to support heart health and also play an important role in the development of a baby's brain while in the womb, so pregnant women especially should aim to include plant-based sources of omega-3 in their diet.
Calcium is essential for the formation of strong bones and teeth. During childhood, bones develop and become more dense until the mid-thirties. The combination of adequate dietary calcium intake and vitamin D levels in conjunction with regular exercise is essential to the development of bone mineral density and to helping safeguard against the development of osteoporosis (brittle bones) in later life.
Lacto-vegetarians typically receive most of their calcium intake from dairy products. Other sources of calcium include tofu, dried figs, pulses, tahini, sesame seeds, and some green vegetables (such as kale). Soybased dairy products are typically low in calcium. Individuals are encouraged to either opt for brands that are fortified with calcium or ensure that calcium intake from other foods is sufficient.
Zinc is an essential nutrient for health, growth, male fertility, and wound healing. Vegetarian diets in general may not always provide adequate intake, so it is important for lacto-vegetarians to be aware of zinc-rich foods. These include cheese, pulses, nuts, seeds, and whole-grain cereals.
Risks associated with lacto-vegetarian eating patterns are minimal as long as steps are taken to ensure adequate consumption of required nutrients. If a vegetarian diet is too restrictive, it may lead to malnutrition and vitamin and mineral deficiencies, adversely affecting overall health.
According to the Academy of Nutrition and Dietetics (formerly the American Dietetic Association), vegetarian diets have been associated with a reduced risk of heart disease, high cholesterol, hypertension (high blood pressure), type 2 diabetes, and cancer. Vegetarians also tend to be leaner and are less likely to be obese than people who regularly eat meat. It is important to note, however, that risks of these illnesses in meat eaters are also reduced if dietary intake is based on the US dietary guidelines.
See also Antioxidants ; Calcium ; Flexitarian ; High-fiber diet ; Iron ; Low-fat diet ; Omega-3 and omega-6 fatty acids ; Vegetarianism ; Vitamin B12 ; Zinc .
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Annette L. Dunne, BSc (Hons) MSc RD
Revised by David Newton