Overview of plant-based Diets
The popularity of plant-based diets including vegetarian and vegan lifestyles has increased over the years. In 2019, approximately 2.5 million Australians reported following a plant-based diet. Many Australians may choose to follow a plant-based diet due to ethical, personal, religious, health, economic or environmental reasons.
Definitions of plant-based diets
It’s important to distinguish the differences as this is likely to result in more or less risk of developing nutritional deficiencies. Vegetarian diets generally exclude all animal flesh but in addition, some may choose to consume dairy and eggs (lacto-ovo), eggs only (ovo) and dairy only (lacto).
Vegans typically avoid consuming the flesh of animals and fish as well as products made from animals and fish (i.e. dairy, eggs, cheese, fish oil etc.). A strict vegan lifestyle not only considers what is eaten but what cosmetics or clothes you choose to buy.
Well-constructed and planned vegetarian and vegan diets can be achieved, however, athletes and regular exercisers need to be well equipped with knowledge to substitute with suitable alternatives to prevent nutrient deficiencies and ensure that they recover well from exercise.
Australians that may be at higher risk of nutritional deficiencies when following a plant based diet include:
- Children and adolescents – due to higher nutrient and energy needs
- Elderly – due to increased nutrient needs and reduced bioavailability
- Athletes with very high energy needs –higher fibre content of plant-based diets may induce early satiety that can reduce energy intake.
- People with gastrointestinal conditions – due to food intolerances, bowel surgery and digestive issues.
- People living with diabetes – due to the higher carbohydrate content and its impact on blood glucose management
For the most part, whole-food plant-based diets supply ample carbohydrates from wholegrain breads and cereals, fruits, milk and yoghurt (soy, coconut or almond), starchy vegetables, rice, quinoa, pasta, legumes/ beans and lentils. It is unlikely that an athlete will not meet their daily and around training/ competition carbohydrate needs.
Plant sources of protein and omega-3 fatty acids (EPA & DHA) may not be so easily consumed in the recommended amounts. Careful attention needs to be paid to the quality, quantity and spread of protein each day, including adequate intake of leucine (a branched chain amino acid) to support recovery and adaptation from training.
Other nutrients that need special consideration on plant-based diets include:
- Vitamin B12
- Vitamin D
Consumption of plant-based drinks fortified with calcium (120mg/ 100mL) such as soy, almond, oat, rice and coconut milk can be suitable alternatives to dairy milk to meet calcium needs. However, not all plant-based drinks provide an equivalent source of protein compared with dairy milk.
|Protein||Grains, legumes, beans, tofu, lentils, quinoa, nuts, seeds, soy milk, soy yoghurt, split peas|
|Iron||Legumes, beans, grains, nuts, seeds, dark green leafy vegetables, fortified breakfast cereals|
|Calcium||Tofu (calcium set), fortified plant-based drinks and juice, kale, broccoli, almonds, sprouts, bok choy, cauliflower|
|Zinc||Beans, nuts, seeds, oats, wheat germ, nutritional yeast|
|ALA||Flax seeds, walnuts, chia seeds, hemp seeds|
|EPA & DHA||Seaweed, microalgae, algae|
|Vitamin B12||Supplements, fortified foods, plant-based drinks, nutritional yeast (fortified), mushrooms|
|Iodine||Seaweed, cranberries, potatoes, prunes, navy beans, iodised salt|
|Vitamin D||Lichen-derived D3 supplements, safe sunlight exposure|
|Table 1 provides a comprehensive list of plant sources of common foods that contain nutrients needing special consideration inplant-based diets.|
ALA = alpha-linolenic acid; EPA = eicosapentaenoic acid; DHA = docosahexaenoic acid
Source: adapted from Rogerson (2017) 1
Supplements likely required
Muscle creatine stores in vegetarian or vegan athletes is reduced as foods such as meat, fish and chicken that are rich sources of creatine are omitted in plant-based diets. Supplementation of creatine to improve short-term high intensity exercise, muscle hypertrophy and strength may be warranted for some athletes.
Research suggests that muscle carnosine is lower in vegetarian and vegan athletes compared with omnivores. Beta-alanine supplementation has been shown to improve intracellular buffering and act as an antioxidant by increasing muscle carnosine stores however; further research is needed and with any supplement use, seek the advice of an Accredited Sports Dietitian.
Well-constructed and planned plant-based diets such as vegetarian and vegan can be successfully achieved; however careful consideration in some groups is needed to prevent nutrient deficiencies. Ongoing support and monitoring from your medical practitioner or accredited sports dietitian is highly recommended to ensure adequate dietary variety and information about plant-based products available in Australia to help meet daily energy and nutrient needs.