Is a vegan diet better for our physical health?

In terms of physical health alone, a vegan diet has been associated with greater desirable health outcomes and weight loss (1-5,7). However, this is not necessarily due to diet alone. 

A vegan diet is often started in response to an increase in health seeking values, which radiate to other areas of lifestyle (smoking, sleep, stress management, alcohol intake, physical activity). 

Food selection associated with a vegan diet is typically representative of nutrient dense, high plant fibre, low Calorie per bite foods. 

These health and nutrition improvements can be achieved with an omnivorous diet.

A diet that's high in plant foods with some lean meat, dairy, eggs is unlikely to be less ‘healthy’ than a vegan diet. 

In fact due to potential vitamin and mineral deficiencies that arise with veganism, a very strong argument in favour of a “plant based diet with some animal foods sprinkled on top” can be made. 

Is a vegan diet better for athletic performance?

A vegan/vegetarian diet is sometimes perceived as superior for athletic performance, especially among those who turn to Netflix for nutrition education.

A vegan diet can be great for athletic performance, however whether vegan diets are better for performance has not been well studied, or no significant difference has been found (6).

Risks and considerations of a vegan diet

A vegan diet is not risk free.

When you completely eliminate whole food groups you’re exposing yourself to nutrient deficiencies, as animal based foods are high in certain nutrients that plant foods are not (or at least they’re poorly absorbed if coming from plants). 

Vegans can have nutrient poor, Calorie dense diets.

With more people looking for meat-free options, vegan alternatives for just about every indulgence food are being created.

Adopting a vegan/vegetarian diet brings a set of unique considerations that relate to achieving nutritional adequacy that have been well studied at a general, non-athletic specific population level (8).

Eating enough Calories for Vegan Athletes

Total energy (Calorie) demands can vary greatly among athletes depending on total workload and exercise type. 

Your ability to build exercise capacity, muscle mass and strength from the training you’re doing will be impaired when you’re not eating enough.

Consistently eating enough food can be difficult for athletes with very high energy needs (9,11). 

Chronic underconsumption of energy can pose significant health and performance implications that are especially common in athletes who participate in endurance or weight conscious and weight-class-based sports (9,10). 

Vegans eat lots of plants and plants are low Calorie per bite, high in fibre, very filling and typically not hyper-delicious. So eating a lot of Calories can be a little tricky, which makes meeting Calorie demands especially difficult for vegan athletes. 

On average vegans and vegetarians do indeed consume less Calories than omnivores, which likely explains why vegan/vegetarian diets outperform omnivorous diets for weight loss (1-5).

What to do about it?

If an athlete is struggling to eat to their Calorie needs it’s recommended that vegan/vegetarian include some lower fibre, Calorie dense, hyper delicious foods.

Foods that combine sweet, salty, and creamy characteristics on top of a minimally processed whole food foundation (8). 

Protein for Vegan Athletes

Plant protein is less “powerful” to muscle & athletes require more protein than non-athletes (12, 13).

An athlete’s ideal protein intakes range between 1.4 - 2 grams of protein per kilogram of body weight per day.

This intake should maximally promote a positive balance of muscle building to muscle breakdown, recovery and desired training response (12-15). 

On a gram for gram basis, plant proteins are “less powerful” than animal proteins from a muscle growth/retention perspective.

This is largely because plant based proteins are often lacking in one or more essential amino acids (EAA).

Vegan protein sources often come with a high proportion of carbohydrate and fat.

For vegans aiming for fat loss in order to improve performance or make a weight class, it can be more difficult to hit a protein target, without going over your daily Calorie budget.

What to do about it?
It is suggested vegan athletes consume additional protein to counteract the blunted muscle protein building response (16). 

Emphasising variety in protein rich plant foods is also recommended to promote the provision of a full spectrum of EAA’s. 

Consuming an all-inclusive variety of soy-based foods, beans, legumes, nuts and seeds can provide a more robust spectrum of EAA’s without the presence of animal derived protein (16).

Plant proteins come with extra carbs and fats

Lean/low fat meat and dairy products provide a macronutrient (protein, carbohydrates & fat) profile that is almost exclusively protein.

This is less so with plant-based protein-dense foods which typically have higher amounts of carbohydrates and/or fat.

Thus, during any fat loss phases where total Calories are restricted, eating enough protein presents practical difficulty.

What to do about it?

Relying on supplemental protein to boost protein intake is a good idea.

Rice and pea protein powder blends have a favourable amino acid profile, not too dissimilar to dairy based protein supplements (17). 

Fats for Vegan Athletes

With the exception of pescatarian diets, it’s not practical for a vegan/vegetarian to consume sufficient omega 3 EPA and DHA fats, which are found in fatty fish and seafood (18). 

What to do about it?

It is recommended vegan/vegetarian athletes consume an algae-based omega 3 supplement (19).

Micronutrients (vitamins and minerals) for Vegan Athletes

Achieving adequate intakes of micronutrients is a vital consideration of any athlete in order to promote human function and sports performance.

Extra vigilance is required for diets partially or completely excluding animal-based food groups, especially vegan diets.

Meeting your daily vitamin and mineral needs can be achieved with a vegan diet, it might just require extra focus, and sometimes supplements (20). 

 

Vitamin B12 for Vegan Athletes

Vitamin B12 plays an important role in neurological health and can affect exercise performance through fatigue and lethargy.

B12 is present in seafood, red meat, white meat, eggs and dairy.

Vegetarians and pescatarians therefore have an array of dietary options to consume B12, however this is not the case for vegans. 

What to do about it?
Fortified cereals, and nutritional yeast can provide vegans with B12. However, regular monitoring through a medical practitioner is recommended and supplementation is often required (17).

Iron for Vegan Athletes

Deficiency of iron can occur through a lack of presence and absorption.

Vegan diets can contain plenty of iron but the absorption of iron from plants is not so great, therefore vegans are at greater risk of iron deficiency. Iron deficiency can reduce exercise capacity, cause fatigue and impair desired training response.

Thus, iron sufficiency is not only relevant for general health but also athletic performance.

A vegan/vegetarian diet rich in whole grains and legumes provides similar amounts of iron compared to an omnivorous diet, however, as alluded to above, poor absorption of plant derived iron appears to be the primary reason for deficiency in those who exclude animal based foods (21). 

What to do about it?
Vegans and especially female vegans should be conscious of consuming liberal amounts of iron rich plant foods such as whole grains and legumes (22).

Pairing iron rich plant food with fruit or vegetables that are high in vitamin C (such as oranges and broccoli) can promote absorption (21), whilst consuming foods and beverages containing polyphenols (such as tea and coffee) with iron containing foods can have the opposite effect (23).

Zinc for Vegan Athletes

Zinc is a mineral that plays a vital role in immunity, affecting risk of illness as well as testosterone and thus athletic performance (24, 25).

Zinc is abundantly present in a well-rounded whole food focused vegan/vegetarian diet rich in nuts, seeds, legumes and whole grains.

However, similar to iron, absorption of plant derived sources is often limited (20).

As dairy contains dietary zinc that is not prone to poor bioavailability, vegetarians are not necessarily at higher risk of zinc deficiency. 

What to do about it?

Vegans should aim to consume an additional 50% total zinc (20).

Fermenting and/or soaking zinc rich nuts, seeds and legumes reduces the presence of phytates and can enhance absorption.

Supplementing with folic acid, iron, calcium, copper and magnesium without good reason is not recommended as it can impair zinc absorption (26).

 

Calcium for Vegan Athletes

Calcium is a mineral involved in bone integrity, vitamin D absorption and muscle contraction.

It’s important for reducing risk of injury, as well as muscular performance (27).

Calcium is most abundantly found in dairy; thus, deficiency is not a high risk for vegetarians (28).

Green leafy vegetables provide a high proportion of calcium intake for vegans however the presence of oxalates limits absorption (29). 

What to do about it?

It is recommended that vegans consume calcium fortified foods such as calcium set tofu, calcium fortified milk alternatives and if needed, rely on supplementation through a medical professional.

 

Iodine for Vegan Athletes

Iodine is a mineral that plays an important role in thyroid function which regulates our metabolism or “how many Calories we need to keep the lights on”.

Vegetarians and pescatarians are not at notable risk of deficiency because iodine is abundant in seafood and dairy.

What to do about it?

Vegans might consume iodine through small amounts of seaweed, iodised salt and more moderate servings of fortified whole grains (30, 31).

Sports supplements for vegan athletes

The list of sports supplements that can be useful for both vegan and non-vegan athletes is pretty similar.

Protein powder, sports drinks and caffeine work just the same for both groups.

However, the effect of some sports supplements, namely creatine monohydrate and beta alanine, may be more profound in vegan/vegetarian athletes (32, 33).

Creatine for Vegan Athletes

Maximising intracellular phosphocreatine stores enhances short term high intensity performance, skeletal muscle size and maximal strength.

Meat provides a portion of creatine.

As vegan/vegetarians exclude meat from their diets, the effects of creatine monohydrate supplementation can be more profound due to lower pre-existing muscle creatine levels.

Note that even in omnivorous athletes, supplementation is required to fully saturate intracellular stores (34).

What to do about it?

It is recommended that vegan athletes supplement with 3-5 grams of creatine monohydrate per day.

A week-long loading phase of 0.3 grams per kilogram of body weight per day is not required but will speed up the saturation process significantly compared to a consistent 3-5 grams per day (35).

Beta alanine for Vegan Athletes

Beta alanine is a precursor to carnosine.

Concentrations of muscle carnosine are lower in vegan/vegetarians compared to omnivores as beta alanine is found in red meat and poultry (33). 

What to do about it?

4 weeks of beta alanine supplementation at a dose of 4-6 grams per day has a more profound enhancement of intermittent high-intensity exercise lasting 1-4 minutes in vegan/vegetarians compared to omnivores who commence supplementation (36).

Split doses are recommended to take care of the single, currently known side effect of beta alanine which is tingling and may cause discomfort for some athletes. 

 

Conclusion

Vegan diets are growing in interest and popularity among athletic and non-athletic populations creating demand for accurate and practically applicable nutrition information.

Ticking off nutrition “check boxes” as a vegan athlete is certainly achievable, however takes a bit of work and know-how.

Athletes considering partially or completely eliminating animal food groups should consult a sports nutritionist or dietitian. 

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