One of the biggest misconceptions switching from a largely meat-based to plant-based diet is whether it is possible to get enough protein into the diet. More specifically in sports nutrition, whether plant-based foods are enough to help support optimal performance and stimulating muscle growth.
We are aware of the many health benefits to adopting a more plant-based diet. Research has shown associations with a reduced risk of heart disease, certain cancers, type 2 diabetes, as well as contributing risk factors of these diseases such as lowered LDL cholesterol and lowered blood pressure. By removing meat from the diet, intake of saturated fat typically reduces, as well as an increase of fibre, vitamins and minerals and phytonutrients.
The research is still relatively limited on the effectiveness of a plant-based diet in improving performance in athletes but we do know that with an increase in phytonutrients and antioxidant activity, this will ultimately reduce stress and inflammation in the body, as well as playing a large role in supporting immune function. Consequently, helping to enhance the recovery process, as well as reducing the risk of illness in athletes.
Although there is the myth regarding whether it is achievable to consume adequate protein on a plant-based diet, it is totally possible. Athletes do require more protein than the general population, which is typically advised between 1.2 - 2 g per kg of body weight per day, depending on the individual as well as the intensity and duration of the activity. However, with additional planning ahead and education, it is possible to obtain this quantity of protein without the consumption of meat, for example from eggs and dairy products, beans, lentils, chickpeas, quinoa, nuts, seeds, tofu, peas, other whole grains, as well as plant-based protein supplements.
Plant-based protein sources are often incomplete sources, lacking some of the essential amino acids (those that cannot be made by the body so have to come from dietary sources). This is typically methionine, lysine and tryptophan. Plant sources also contain less branched chain amino acids (BCAAs) - leucine, isoleucine and valine. In particular leucine, which plays an important role as a trigger of muscle protein synthesis as well as a role in stimulating recovery.
BCAAs can be found in seeds, nuts and chickpeas and leucine in particular can be obtained from soy beans, pumpkin seeds and lentils; thus, it is possible to obtain these amino acids by consuming a variety of protein rich plant-based foods. There are also a wide variety of plant-based supplements available, typically including a blend of soy, pea, rice and hemp protein, which may be beneficial for convenience.
Cereals such as rice and wheat contain less lysine; however, beans, lentils and tofu are rich sources of lysine. Similarly, beans and lentils lack methionine yet cereals are rich in methionine. Therefore, by consuming a wide variety of different plant-based sources of protein, they will complement each other and will help to support a complete amino acid profile. Consequently, the proposed lowered muscle protein synthesis response to plant-based protein sources can be supported by the combination of multiple different plant sources.
Research also suggests that consuming larger amounts of plant protein is an effective tool to compensate for the poorer digestibility and lower quality, compared with animal sources. In particular, when there is a prolonged period until the next meal, a relatively large amount (>40g) of slowly digestible protein may help to prolong muscle protein synthesis response. This is a point worth noting for plant-based athletes prior to sleeping.
To conclude, with some additional planning, as well as education, it is definitely possible to obtain adequate protein from a plant-based diet to support performance, as well as muscle growth. Without the additional planning and appropriate considerations then a plant-based diet, more specifically a vegan diet, can result in deficiencies which may decrease performance.
It is key to consume a wide variety of different protein rich plant foods spread over the course of the day, in all meals. Some great ideas for meals combining various sources include: mixed bean chilli with wholegrain rice, porridge with soya milk and peanut butter, tofu and chickpea curry with rice, pea and chickpea pasta and nut butter on whole grain toast.
Written by Becs Sandwith, who is a Registered Associate Nutritionist with the Association for Nutrition (ANutr). Becs has a BSc degree in Nutrition and an MSc in Clinical Nutrition and Eating Disorders. As well as everyday nutrition, Becs has a great passion for sports nutrition and working with individuals on performance-based goals. You can find more about Becs on her website Becs Sandwith and through her Instagram @bitesbybecs.
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