Fasting and Vegetarian Diets

What is alternate day fasting?

Alternate between days of no restriction with days that provide about 25% of caloric needs

What is whole day fasting?

1-2 days a week of complete fasting

What is time-restricted feeding?

Eating during a condensed time period

What are some cardiometabolic benefits of intermittent fasting?

• Decreased body weight

• Decreased blood pressure

• Decreased LDL choleserol and triglycerides

• Decreased oxidative stress

• Decreased insulin and insulin resistance

What are the pros of intermittent fasting?

• Can be effective as consistent calorie restriction

• May have metabolic benefits

• Time restricted feeding may provide structure for people who eat late at night

• Several variations, so it can be individualized

What are the cons of intermittent fasting?

• Not sustainable for many people

• Not appropriate for all types of people (athletes, diabetes)

• Research is still emerging

What are some reasons for choosing vegetarianism?

Religious/cultural customs

Perceived health benefits

Ethical/philosophical beliefs

Concern for environment and/or animal welfare

What is flexitarian/semi-vegetarian

Avoid eating some animal products (usually red meat) but eat limited amounts of poultry and fish

What is lacto-ovo vegetarian?

Includes milk/dairy and eggs, avoids other animal foods

What is vegan?

Avoids all animal-derived foods

What are the benefits of vegetarian/vegan diets in terms of nutrients?

Lower levels of saturated fat and cholesterol

Higher levels of carbs, fiber, magnesium, folate, antioxidants, and phytochemical.

What are the benefits of vegetarian/vegan diets in terms of risk of disease?

Reduced risk of:

• Obesity

• Hypertension

• Type 2 diabetes

• Cardiovascular disease

• Some cancers

What are the disadvantages of vegan diets?

It can be difficult to eat enough calories or enough protein (especially for athletes).

It can also cause lower levels of:

• Iron

• vitamin B12

• Calcium

• Vitamin D

• Zinc

• Riboflavin

How do vegetarian athletes get enough protein?

They must learn to complement proteins that are not animal-derived.

What does plant protein lack?

Lysine, theonine, tryptophan, sulfer containing amino acids

What do carbs look like for vegetarians?

They are very similar to omnivores and are capable of getting 8-10 g/kg body weight.

What are vegetarians most likely to be deficient in? Why?

IRON!

The problem is that animal products have iron that is easily absorbed, while iron in plant products is non-heme and less easily absorbed.

How can vegetarians avoid iron deficiency?

• Choose foods that are good sources of iron (fortified cerials, tofu, legumes, nuts/seeds)

• Consume vitamin C source at every meal

• Semi-vegetarians can get iron from chicken and fish

How does vitamin C help with iron deficiency?

It increases non-heme iron absorption!

What other thing besides iron are vegetarians likely to be deficient in?

Vitamin B12 → a B12 deficiency is called macrocytic anemia and may be masked by high folate intakes commonly found in vegetarian diets

What is the antioxidant status of vegetarians?

They consume more antioxidants than omnivores! (vitamin C, E, beta-carotene, phytochemicals)

Myth bust: All vegetarians/vegans have a healthy diet

Vegetarian diets CAN BE UNHEALTHY if meat and other animal products are not substituted by nutritionally appropriate foods

Myth bust: all vegetarian athletes are healthy eaters

Vegetarian athletes suffer less heart disease, cancers, high BP, etc, but studies show it is more likely to be from a generally healthier lifestyle.

How does vegetarianism impact athletic performance?

Does not impair physiological response or change endurance performance.

High risk of iron deficiency.

Creatine supplementation might be extra beneficial for supramaximal perforamance.

Can you build significant muscle on a protein diet?

Not as much as omnivores or at a slower rate likely due to less animal fat/more soy hindering production of testosterone.