Diets excluding certain foods or food groups can risk causing deficiencies in different nutrients. Choosing to eat a vegan diet is no exclusion. This can become especially problematic when you live an active lifestyle, want to maximize health and your performance. However, there are ways around this and by making smart food choices and with the right supplements, you can optimize your vegan diet.
First of all, for optimal performance, it is important that the diet reaches your energy needs (if your goal is not to lose weight). An energy deficiency can compromise training results, set you up for illness, muscle mass-loss, reduced strength, bone mass-loss, etc (Rogerson, 2017).
It can be harder to reach your energy needs on a vegan diet since you exclude a lot of energy-dense food, like cakes, ice cream, pizza, etc. A vegan diet is also usually high in satiating fiber and has a low energy density (kcal per gram of food) which makes it more difficult to reach energy needs.
A vegan diet excludes all animal products, this is in contrast to for example lacto-ovo vegetarianism in which you exclude all flesh but can eat dairy products and eggs.
A lot of animal products are rich in protein and fat, and a vegan diet becomes mostly plant-based. Plants usually have a lower protein content and a less favorable amino acid profile, incomplete proteins, meaning; often not a sufficient amount of all essential amino acids. It can, therefore, be difficult to reach an optimal protein intake, both in terms of the absolute amount but also amino acid profile. For this reason, it could be favorable to combine different protein sources that complement each other’s amino acid profiles. For example, combine beans with soybeans and nuts.
Protein is for example important for triggering muscle protein synthesis (building of muscle), decrease muscle protein breakdown, and promote a positive balance between the two, ie favoring muscle building (Phillips, 2016). A recommended protein intake for athletes is around 1.6 g/kg/day in order to optimize strength and muscle mass (Morton et al., 2017).
When in an energy deficit an even higher protein intake could be beneficial with regards to increase in muscle mass gain and increased fat loss with an intake of around 2.4 g/kg/day showing beneficial results (Longland et al., 2016), i.e. 144g/day for a 60 kg and 192 g/kg for an 80 kg individual. These are values that can be really difficult to achieve on a vegan diet when kcals are low on a diet. This is because most vegan protein sources are also high in other macronutrients.
The lower biological value and digestibility of plant-based proteins could warrant an aim for the higher end value of recommendations (or a bit above recommended intake) in order to make sure to get enough of all amino acid and optimal results. Therefore, a vegan athlete could aim for up to, or above, 2 g/kg/day of protein even when not dieting.
In table 1 you can see protein content in some protein rich vegan foods. Important to note though is that while the foods are high in protein, the E% protein (% energy from protein) of vegan food is generally low, meaning; to get a good amount of protein you also get a lot of fats and/or carbs with the protein as an unwanted (or wanted) passenger. E.g. to get 21 g protein from almonds you also get 52 g of fat and around 600 g kcal! This is hardly something you could consume if you want to reach a protein intake of 166 g if your total energy need is 2500 kcal, (you would only get 87.5 g protein).
There are however, vegan protein supplements that are for example soy-, pea-, rice-, or hemp-based. Again, be vary of the amino acid profile, you might need a higher amount of vegan protein supplements compared to whey (milk-based protein source) that have a complete amino acid profile with high levels of leucine (the amino acid that stimulates protein synthesis the most).
Vegan protein sources include different protein supplements (eg soy, pea, rice, hemp), tofu, lentils, beans, oats, quinoa, almonds and seitan. Again, be aware that the protein quality might not be optimal and that you have to combine different sources to get appropriate levels of all amino acids.
Table 1. Protein content in some high protein vegan foods (Rogerson, 2017) and E% protein (Lifesum app).
As for carbohydrates, vegan diets tend to be higher in carbohydrates, fiber, vegetables, and fruits compared to diets containing meat products. This can be beneficial in the aspect that you get lots of vitamins and minerals from the fruits and vegetables.
In the pursuit of reaching your protein goal you most likely will get some carbohydrates as well. Since it is more difficult for a vegan to reach a higher protein intake it could be recommended that carbohydrate sources that are also relatively high in protein are consumed. For example, lentils, beans, and grains.
However, if you are an endurance athlete and require a very large amount of carbohydrates, the foods mentioned above might not be optimal if you can´t tolerate the high fiber content of these foods. Then foods like rice, noodles, and pasta might complement the protein and fiber-rich carbohydrate sources. Potatoes are also a great source of carbohydrates but have a low protein content.
Vegan carbohydrate sources are for example lentils, beans, and grains (oats, rye, etc), potatoes, rice noodles, chickpeas.
The total and saturated fat intake in a vegan diet are generally lower than non-vegan diets. Also, their omega-3 intake tends to be lower. This might not be optimal. Omega-3 fatty acids are important for normal growth and possibly for cardiovascular health (Rogerson, 2017). Therefore, a sufficient intake of omega-3 is vital.
Vegan foods that can be consumed to get omega-3 fats are flax seeds, chia seeds, and walnuts (walnuts contain alpha lipoic acid, ALA, which is converted to the omega-3 fatty acid eicosapentaenoic acid (EPA), but only with ~8% efficiency). To get the omega-3 fatty acid docosahexaenoic acid (DHA), which are primarily found in fish and seafood, microalgae oil is a good vegan source (1-2 g microalgae oil to reach a DHA dose of 500-1000 mg) (Rogerson, 2017). Other sources of fats include nuts, avocado, oils etc.
Micronutrients at higher risk of under-consumption and therefore deficiency on a vegan diet include vitamin B12, iron, zinc, vitamin D, calcium, and iodine.
Vitamin B12 (Cobalamin)
- Why risk for deficiency: Dietary sources of Vitamin B12 is typically animal products. Plants usually have a low vitamin B12 content, but can contain some if contaminated by manure or animal waste. Around 50% of vegans are vitamin B12 deficient (Rogerson, 2017).
- Effects of deficiency: Neurological and hematological symptoms. Vitamin B12 is, for example, essential for the nervous system and DNA synthesis.
- Good vegan sources: Vegans need to supplement with vitamin B12 in order to not risk deficiency. Supplemental vitamin B12, B12-fortified cereals, nutritional yeast, and plant milk are recommended (although the bioavailability and absorption are limited, partly due to intrinsic factor (a factor secreted in our stomachs)). It could, therefore, be necessary to monitor B12 levels at a medical practitioner to make sure there is no deficiency present.
- Why risk for deficiency: The absolute amount of iron in the diets of vegans and non-vegans are about the same (whole-grains and legumes are rich in iron) but the bioavailability is different. Iron is rich in meat. The iron present in meat is in a molecule called haeme-iron, iron bound to a haeme molecule (this is how iron is bound in our own red blood cells and why red blood cells can carry oxygen). This form of iron has a much higher bioavailability than non-haeme iron -> vegan sources are not absorbed as readily. Vegan sources of iron can also contain other molecules that inhibit the iron uptake.
Fertile females have a higher risk for deficiency than males due to iron loss each month. Male vegans seem to have similar iron status as non-vegans. Whereas vegan women are more likely to have iron-deficiency compared to non-vegans. Lower levels of iron potentially increase absorption of iron, this seems to be a compensation by the body to tailor the intake to the appropriate levels.
- Importance and effects of deficiency: Anaemia (decrease in the oxygen-carrying red blood cells). Can cause tiredness, weakness, and fatigue.
- Good vegan sources: Grains, legumes, nuts, seeds, fortified foods, green vegetables. Consume iron-rich foods with vitamin C, this can actually increase iron absorption.
- Why risk for deficiency: Plant-based foods have lower bioavailability, but the body seems to adapt to lower intakes by reducing the losses and increase the uptake.
- Importance and effects of deficiency: Important for cell growth, protein metabolism, and repair.
- Good vegan sources: Beans, whole grains, oats, seeds, and nuts or a dietary supplement (avoid co-ingestion of other minerals like iron, magnesium, calcium, copper since this absorption of zinc).
- Why risk for deficiency: Calcium is mainly found in large amounts in dairy products. Vegans, therefore, risk under-consumption of this mineral. However, the body seems to regulate the calcium uptake based on calcium status in the body.
- Importance and effects of deficiency: Calcium is important for bone health, nerve transmission, muscle contraction, and vitamin D metabolism (Rogerson, 2017).
- Good vegan sources: Broccoli, tofu (calcium set), fortified plant milk, cauliflower, kale, sprouts.
- Why risk for deficiency: Iodine is found in some foods excluded in the vegan diet including fish and dairy products. Iodine status seems to vary between vegans and it´s not clear whether a deficiency is more common in vegans than non-vegans.
- Importance and effects of deficiency: Essential for physical and mental growth, thyroid function and metabolism.
- Good vegan sources: Iodized table salts, potatoes, seaweed.
- Why risk for deficiency: Vitamin D can be synthesized by humans from sun exposure. We can also get vitamin D from the diet, mainly from animal products and fortified foods. Vegans with low levels of sun exposure can, therefore, develop a vitamin D deficiency.
- Importance and effects of deficiency: Vitamin D is for example important for muscle function and calcium metabolism.
- Good vegan sources: Lichen-derived D3 supplements.
A healthy diet is important for everyone, but for the active person that want optimal performance, it might be even more important to fine tune the diet. On a vegan diet, as with any diet that excludes certain foods, it might be more difficult to achieve optimal nutritional status.
A vegan diet is generally rich in carbohydrates, fruits, vegetables, and fiber. This usually means that you get a lot of healthy vitamins and minerals from the diet and that you possibly are less likely to overconsume food and gain fat. However, there are some nutrients that are usually less abundant in vegan foods compared to non-vegan foods. These include complete sources of protein (with ample amounts of essential amino acids) with good bioavailability, fats, vitamin B12, omega-3 fatty acids, calcium, and iodine. There are ways around this, one just has to be a bit more mindful of the diet and make sure to add a few key ingredients or supplements.
Please share your favorite vegan foods and recipes in the comments and why you like them 😀
- Check out the vegan recipes in the LIfesum app. Frida Westman, the nutritionist at Lifesum, has created some awesome tasty vegan recipes!
Post writen by: Fredrik Wernsta, Sept 19, 2017
Longland, T.M., Oikawa, S.Y., Mitchell, C.J., Devries, M.C., Phillips, S.M., 2016. Higher compared with lower dietary protein during an energy deficit combined with intense exercise promotes greater lean mass gain and fat mass loss: a randomized trial. Am. J. Clin. Nutr. 103, 738–746. doi:10.3945/ajcn.115.119339
Morton, R.W., Murphy, K.T., McKellar, S.R., Schoenfeld, B.J., Henselmans, M., Helms, E., Aragon, A.A., Devries, M.C., Banfield, L., Krieger, J.W., Phillips, S.M., 2017. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. Br. J. Sports Med. doi:10.1136/bjsports-2017-097608
Phillips, S.M., 2016. The impact of protein quality on the promotion of resistance exercise-induced changes in muscle mass. Nutr. Metab. 13, 64. doi:10.1186/s12986-016-0124-8
Rogerson, D., 2017. Vegan diets: practical advice for athletes and exercisers. J. Int. Soc. Sports Nutr. 14, 36. doi:10.1186/s12970-017-0192-9