Vegetarian Diets
Presented by Janice Hermann, PhD, RD/LD
OCES Adult and Older Adult Nutrition Specialist
Types of Vegetarian DietsVegetarians:
exclude meat, poultry, fish, seafood and other animal products from their diets
Lacto-ovo-vegetarians: include milk, milk products, and eggs, but exclude meat, poultry, fish and seafood
Lactovegetarians:include milk and milk products, butexclude meat, poultry, fish, seafood, and eggs
Vegans:exclude all animal and animal-derived foods (meat, poultry, fish,
eggs, and dairy products)Macrobiotics
Extremely restrictive diets limited to a grains and vegetables
Vegetarian DietsVegetarian diets are classified based on
what they exclude, but foods excluded not nearly as important as the foods included.
Vegetarian diets that include a variety of whole grains, vegetables, legumes, seeds, nuts, and fruits offer complex carbohydrate, fiber, a variety of vitamins and minerals and low fat – all of which reflect the Dietary Guidelines.
Health Benefits Health impacts of vegetarian diets would be
easy if the only difference was what they ate.Many vegetarians also have lifestyles
differences:Maintain a healthy weightDo not use tobaccoUse little (if any) alcoholAre physically active
Make it difficult to determine if health benefits due to diet or other lifestyle factors.
Health BenefitsEven when dietary effects are correlated with
health benefits, this only means health effects go with diets, not that health effects are caused by diet.
Still, even with cautions, research suggest well-planned vegetarian diets offer adults nutrition and health benefits.
Body WeightVegetarians tend to have healthier body
weight than non-vegetarians Vegetarians’ lower body weight is correlated
with their higher fiber and lower fat intakesSince being overweight can increase many
health risks, this gives vegetarians a health advantage
Blood PressureVegetarians tend to have lower blood
pressure than non-vegetarian A healthy body weight along with a diet low in
total fat and saturated fat and high in fiber, fruits and vegetables helps maintain a healthy blood pressure
Other lifestyle factors, such as not using tobacco, little (if any) alcohol use, and being physically active help lower blood pressure
Heart DiseaseVegetarians tend to have a lower incidence of
heart disease than non-vegetarians Dietary factors related to heart disease risk are
high total fat, saturated fat, and cholesterolVegetarian diets tend to be lower in total fat,
saturated fat, and cholesterolVegetarian diets tend to supply monounsaturated
fats from olives, seeds, and nuts and polyunsaturated fats from vegetable oils associated with decreased heart disease risk
Vegetarian diets also tend to be higher in dietary fiber associated with lower heart disease risk
Heart DiseaseMany vegetarian diets include soy products,
which offer additional benefits Even when calories, protein, carbohydrate, total
fat, saturated fat, unsaturated fat, alcohol, and fiber intakes are similar, diets using soy as a protein result in lower blood cholesterol and triglyceride levels than those using muscle meats
Soy products also contain phytochemicals which may also have a role in lowering blood cholesterol
CancerVegetarians tend to have lower rates of
certain types of cancer, most notably colon cancer, than non-vegetariansLower cancer rates may be due to the higher
fruit and vegetable and lower fat intake Fruits and vegetables provide ample amounts of
fiber, antioxidant nutrients and phytochemcials and low fat
Planning Vegetarian DietsVegetarians and non-vegetarians have the
same meal-planning challenge – utilizing a variety of foods to provide all the nutrients needed while staying within a calorie range that maintains a healthy weight.
Vegetarian Food GuideMost vegetarians consume adequate
amounts of nutrients found in abundance in plant foods including thiamin, folate, and vitamins B6, C, A, and E
Vegetarian food patterns help to ensure adequate intakes of nutrients vegetarian diets might otherwise lack including iron, zinc, calcium, vitamin B12, and vitamin D
Planning Vegetarian DietsThe Dietary Guidelines for Americans, 2010
contains adaptations to the USDA Food Pattern for lacto-ovo vegetarians and vegans.
ProteinRecommended protein intakes for
vegetarians is the same as for non-vegetarians, although some have suggested that vegetarian protein requirements should be higher due to the lower digestibility of plant protein.
Lacto-ovo-vegetarians who include milk and eggs receive high-quality proteins and are likely to meet protein needs.
ProteinEven vegans, who exclude milk and eggs, able
to meet protein needs if consume adequate calories and varied sources of protein
Whole gains, legumes, seeds, nuts, and vegetables can provide adequate amounts of protein and all the amino acids.
Many plant based protein foods tend to be lower in saturated fat and higher in fiber and some vitamins and minerals than animal based protein foods.
Vitamins and Minerals Getting enough iron can be a problem for
both vegetarians and non-vegetarians. However, vegetarians must pay particular
attention to iron intake. Iron is poorly absorbed from plant foods
such as legumes, dark green leafy vegetables, iron-fortified cereals, and whole-grain breads and cereals.
Vitamins and Minerals Because iron is less available from plant
sources, the iron DRI for vegetarians is higher than non-vegetarians.
Fortunately, the body is more efficient at absorbing iron when dietary intake is low.
In addition, vitamin C increases iron absorption, and vegetarian diets typically provide ample fruits and vegetables rich in vitamin C.
Vitamins and MineralsZinc is similar to iron. Meat is a rich food
source of zinc; and zinc is not well absorbed from plant sources.
In addition, soy, which is commonly consumed as a meat alternate in vegetarian meals, interferes with zinc absorption.
However, most adults who follow vegetarian adults are not deficient in zinc.
Vitamins and MineralsThe best advice in terms of zinc for
vegetarians is to eat a variety of nutrient-dense foods; include whole grains, nuts, and legumes.
Oysters, crabmeat, and shrimp are also rich in zinc for vegetarians who include seafood in their diets.
Vitamins and MineralsCalcium intake of lactovegetarians is similar
to the general population. However, vegetarians who do not include
milk and milk products are at risk for inadequate calcium intake.
Vitamins and MineralsIf milk is not included in the diet,
recommendations are to choose ample amounts of calcium-rich foods, such as calcium-fortified juices, soy milk, and breakfast cereals.
Including plenty of these calcium rich foods is especially important for children and adolescents.
Vitamins and MineralsSome other good food sources of calcium
include figs, some legumes, some green vegetables such as broccoli and turnip greens, some nuts such as almonds, certain seeds such as sesame seeds, and calcium-set tofu.
Because plant sources of calcium can be limited, including a variety of calcium rich foods is important.
Vitamins and MineralsThe DRI for vitamin B12 is low, but vitamin
B12 is only found in animal foods. Bacteria used to ferment soy products such
as tempeh may provide some vitamin B12, but much of the vitamin B12 may be an inactive form.
Vitamins and MineralsSeaweeds such as nori and chlorella supply
only a very small amount of vitamin B12, and excessive intake of these foods can result in iodine toxicity.
To protect against vitamin B12 deficiency, vegans must depend on foods fortified with vitamin B12 such as soy milk and breakfast cereals or dietary supplements.
Vitamins and MineralsVitamin D is also a nutrient of concern for
vegetarians to support bone growth and maintenance.
Vegetarians who do not consume foods fortified with vitamin D and do not receive enough sunlight exposure to synthesize adequate vitamin D may need supplementation.
Vitamins and MineralsAdequate vitamin D intake is especially
important for infants, children, and older adults.
Young children following vegan diets who live in northern climates during winter months can easily develop rickets which is a vitamin D deficiency disease.
Omega-3 Fatty AcidsVegetarian diets typically provide adequate
levels of omega-6 fatty acids, but provide inadequate levels of omega-3 fatty acids.
The imbalance in omega-6 and omega-3 fatty acids can slow the production of EPA and DHA.
Omega-3 Fatty AcidsIf seafood and eggs are not included in the
diet, dietary intake of EPA and DHA is low as well.
To make up for this inadequacy, vegetarians need to include good sources of linolenic acids in their diet, such as flaxseed, walnuts, soybeans, and their oils.
Vegetarian Diets Through the Life SpanCarefully planned vegetarian diets can
provide adequate calories and nutrients to support good health.
However, obtaining adequate calories and nutrients can be difficult for vegans who excludes all animal products; particularly for growing children and pregnant and lactating women.
Vegetarian Diets Through the Life SpanPlant foods typically provide fewer calories
than animal foods. Lower calorie intakes can be helpful for
overweight adults, it can be harmful for growing infants, children and adolescences.
Diet during pregnancy, lactation, infancy, childhood, and adolescence must provide adequate calories and nutrients for growth and development.
Healthy Food ChoicesIn general, adults who follow vegetarian
diets have lower risks of developing many chronic diseases, including obesity, high blood pressure, heart disease, and cancer.
However, there is nothing magical about vegetarian diets. Vegetarianism is not a religion, but rather a pattern of eating that chooses plant foods to provide necessary nutrients.
Healthy Food ChoicesDiet quality doesn’t depend on whether
meat is included, but on whether the other food selected are nutritionally sound.
A diet that includes plenty of fruits, vegetables, whole grains, legumes, nuts, and seeds is higher in fiber, antioxidant vitamins and minerals, and phytochemcials, and lower in total and saturated fat.
Healthy Food ChoicesThe key to nutritional adequacy of
vegetarian diets is including a variety of foods.
Restrictive vegetarian eating plans, such as macrobiotic diets that limit selections to a few grains and vegetables cannot possibly deliver a full variety of nutrients.
Healthy Food ChoicesBased on current research of the role of diet
and chronic disease, the USDA Daily Food Plan also recommends a diet pattern that includes plenty of fruits, vegetables, whole grains and legumes.
Such a diet plan provides the same health advantages of a vegetarian diet if lean meat intake is limited to the amounts recommended by the USDA Daily Food Plan.
Healthy Food ChoicesIn general, vegetarian diets can promote
good health. However, both vegetarian and non-
vegetarian diets can be detrimental to health if fat intake is high.
Vegetarians who consume large amounts of foods high in fat invite the same health concerns as non-vegetarians who consume high fat diets.
Healthy Food ChoicesIn addition, both vegetarians and non-
vegetarian diets can be low in some nutrients if poorly planned.
Poorly planned vegetarian diets are often low in iron, zinc, calcium, vitamin B12, and vitamin D
Poorly planned non-vegetarian diets are often low in vitamin A, vitamin D, folate, and fiber.
Healthy Food ChoicesIn general, negative health aspects of any
diet, including vegetarian diets, reflect poor diet planning.
Careful planning to adequate calories and problem nutrients can ensure adequacy.
Healthy Food ChoicesIt’s important to remember that diet is only
one factor affecting health. In addition to diet, not smoking, moderate
alcohol intake (if at all), regular physical activity, and adequate rest all contribute to health.
Healthy lifestyles early in life seem to be the most important step one can take to reduce risk of disease later in life.