Topic 4.6 - Vegetarian Diets

What does it mean to be a vegetarian?

* vegetarianism is the dietary practice of consuming foods of plant origin, including vegetables, fruit, grains, and nuts, and *excludes* the consumption of
* Meat
* Fowl (birds)
* Fish

Semivegetarian (or flexitarian)

food consumed: fruits, vegetables, grains, nuts, legumes; *rarely* meat, seafood, poultry, eggs, dairy

* *typically exclude or limit red meat*; may also avoid other meats

Pescovegetarian (pescitarian)

foods consumed: similar to semivegetarian but *excludes*

*poultry*

* pesco means “fish,” the only animal source of protein in this diet

Lacto-ovovegetarian

foods consumed: fruits, vegetables, grains, nuts, legumes, dairy products (lacto), and eggs (ovo)

* *excludes animal flesh and seafood*

lacto-vegetarian

similar to lacto-ovovegetarian but excludes eggs

* relies on milk and cheese for animal sources of protein

Ovovegetarian

foods consumed: fruits, vegetables, grains, nuts, legumes, and eggs

* *excludes dairy, flesh, and seafood products*

vegan (also called strict vegetarian)

foods consumed: only plant-based foods (fruits,vegetables, grains, nuts, seeds, legumes)

* may not provide adequate vitamin B12, zinc, iron, calcium

macrobiotic diet

foods consumed: vegan-type diet; becomes more strict until almost all foods are eliminated; at the extreme, only brown rice and water or herbal tea

* taken to the extreme, can cause malnutrition and death

fruitarian

foods consumed: only raw or dried fruit, seeds, nuts, honey, and

vegetable oil

* *very restrictive;* deficient in protein, calcium, zinc, iron, vitamin B12, riboflavin, other nutrients

raw food diet

foods consumed: vegan-type diet with foods either sprouted or minimally heated

why do people choose vegetarian diets?

1. religious, ethical, food safety

* example: Many Hindus are vegetarian – the cow is a sacred animal
* ethical reasons related to practices in animal industry
* meat handling and illness


2. ecological benefits: impact of meat production on environment and greenhouse gas emissions
3. health benefits

vegetarianism in canada

* canada is home to approximately 466 000 vegans, and approximately 2 650 000 canadians have restricted dietary preferences due to food intolerances or allergies

positive health aspects of following a vegetarian dietary pattern

Health benefits of vegetarian diets:

* reduced intake of fat and total energy, reducing risk for obesity and type 2 diabetes
* lower blood pressure
* reduced risk for heart disease
* fewer digestive problems
* reduced risk for some cancers (colorectal)
* reduced risk for kidney stones and gallstones

positive health aspects of following a flexitarian dietary pattern

Health benefits of flexitarian diets:

* improved markers of metabolic health
* reduced risk for obesity and type 2 diabetes
* lower blood pressure

life cycle

* well-planned meet nutrient needs and growth at all stages of life cycle
* more restrictive = likely to be unhealthy

example #1: pregnancy

* pregnancy outcomes similar to omnivores


* special consideration for iron, zinc, B12, EPA, DHA

example #2: vegan diets appropriate for young children

* lacto-ovo diet as nourishing as a diet that includes meat and fish
* zinc and heme iron would be low in a lacto-ovo diet
* need to enhance foods to provide these nutrients

example #3: children and teens

* lower risk for overweight/obesity
* increased fruits/vegetables; fewer sweets, salty snacks, and saturated fats
* ample energy = normal growth
* special consideration for vit B12, vit D, calcium, iron and zinc

example #4: older adults

* nutrient intakes are similar or better than average omnivore
* nutrient dense choices
* protein – need may increase;
* special consideration vit D, vit B6, vit B12

bioavaliability

* the degree to which the human body can absorb and utilize any given nutrient

vitamins to consider in a vegetarian diet

* Vitamin B12
* Vitamin D
* Riboflavin

Vitamin B12

Function:

* assists with DNA synthesis
* protection and growth of nerve fibres
* fermented foods (tempeh, nori, nutritional yeast – not adequate sources)
* not reliable sources because they do not act the same way in the human body

examples of foods with Vitamin B12 for vegetarian diet

* yogurt
* low-fat milk
* cheese
* eggs

examples of food with Vitamin B12 for vegan diet

* fortified plant-based beverages
* fortified foods (e.g. cereal)
* B12 supplements

Vitamin D

Function:

* contributes to bone growth and regeneration
* facilitates calcium absorption
* sunlight activates vitamin D in skin (Canada May-Oct)
* supplement 1,000 IU , 10 mcg

Riboflavin

Function:

* promotes release of energy
* component of coenzymes (FMN & FAD) for carbohydrate and fat metabolism
* part of antioxidant Glutathione Peroxidase
* supports normal vision and skin health

Mineral Considerations for the Vegetarian Diet

* iron
* calcium
* zinc

Iron

Function:

* assists with oxygen transport
* involved in making amino acids and hormones
* vegetarians consume iron intakes equal to or greater than omnivores BUT body stores are lower

Heme vs. Non-Heme Form

Food contains two types of iron

* heme iron: iron that is part of hemoglobin and myoglobin; found only in animal based foods such as meat, poultry, fish
* non-heme iron: iron not part of hemoglobin or myoglobin; found in animal and plant based foods
* Bioavailability of heme iron is greater than from non-heme

iron pt.2

* bioavailability of non-heme iron
* absorption varies depending on status and dietary enhancers and inhibitors
* DRI for vegetarians = 1.8 x
RDA

• Spinach and dark leafy greens
• Raisins
• Whole grains and
enriched/fortified grains
• Legumes (beans)

Iron bioavaliability (enhancers and inhibitors)

enhancers:

* low body stores
* vitamin C
* citric acid
* other organic acids

inhibitors:

* phytates
* polyphenolics

Calcium

Function:

* bone health maintenance
* assists with muscle contraction, blood pressure, and nerve transmission

Calcium pt.2

1. lacto-ovo vegetarians typically adequate calcium intake

* vegans
* Kale
* Broccoli
* Bok choy
* Beans
* Nuts and seeds
* Tofu


2. Calcium-fortified products

* soy beverages
* breakfast cereals
* orange juice

calcium bioavaliability

enhancers:

Low oxalate vegetables

* kale
* turnip greens
* bok choy
* Chinese cabbage
* vitamin D

inhibitors:

* oxalate
* phytate
* fibre

Zinc

Function:

* assists with DNA and RNA synthesis
* assists with immune function
* assists with growth
* many plants are good sources of zinc; poorly extracted compared to animal sources
* non-meat sources:


1. whole grains
2. beans
3. nuts and seeds
4. zinc-fortified breakfast cereals
5. soy products

zinc bioavaliability

enhancers:

soaking and sprouting

* beans
* grains
* nuts
* seeds
* leavening bread
* organic acids (citrus)

inhibitors:

* phytates