Are Vegan Kids Really 'shorter' and 'weaker'?
Plant based diets have been rising in popularity in recent years, from celebrity ‘diets’, to chefs including plant-based meals in their restaurants. Plant based diets consist primarily of plants and forego anything of animal origin (meat, eggs, milk, even honey in most cases). Plant-based is remarkably similar to a vegan diet in terms of what they include and exclude in their diet, but people who are vegan tend to extend their beliefs to everything related to animals – they don’t support rodeos, use of leather or riding horses, among other things. Vegetarian diets, on the other hand, have been around since at least the 19th century, and gained popularity in Western countries in the 60’s and 70’s. People who follow a vegetarian diet do not eat meat, but happily include eggs and dairy, distinguishing them from both vegan and plant based.
As is normally the case, the rise in popularity of plant-based diets has brought with it its critics who claim many different assertions, from nutrient deficiencies and ‘weakness’, to going as far as to say they will make you terribly sick. A good example of this is the number of news articles that popped up in relation to a study on Polish children who followed omnivorous, vegetarian or vegan diets recently published in the American Journal of Clinical Nutrition (1). These news articles are claiming this study found vegan children are “shorter” and “weaker” or “have weaker bones”. But are these claims true? The simple answer – No. But there is certainly more to the story. People following a vegan, or plant-based diet do have an increased risk of certain vitamin and mineral deficiencies, including calcium, iron and vitamin B12. But an increase in risk certainly does not translate into kids being “shorter” and “weaker”. In fact, it has been demonstrated consistently that people who follow a vegan diet have lower cholesterol levels (that’s the LDL or ‘bad’ cholesterol), lower weight, and overall better cardiovascular health (2).
What was interesting about this study was they found kids following vegan diets to actually have a higher intake of iron, folate, polyunsaturated fats (good fats), vitamin C, magnesium and fibre, compared to those on omnivorous diets. While kids on omnivorous diets had a greater intake of vitamin D and B12 compared to vegans, omnivores had the highest intakes of saturated fat, cholesterol and sucrose (sugar). What these results start to suggest is that the kids following a vegan diet actually had higher intakes of lots of vitamins and minerals, and lower intakes of saturated fats and sugars.
What are the risks of a vegan diet?
Despite the positive health benefits of plant-based diets for both adults and children, it is clear from the evidence that children, especially, are at a greater risk of some nutrient deficiencies including calcium, iron, B12 and zinc. But there is no doubt that with a well-balanced and planned diet, a plant-based diet is perfectly safe for children of all ages (except infants if they are unable to breastfeed, but this is another matter altogether). So, it is not to say plant-based diets don’t need to be monitored and watched carefully, but just like an omnivorous diet, a well-balanced and planned diet consisting of mainly whole and minimally processed foods is the best thing for health, regardless of whether or not you include meat in your diet.
But I think that is the point of this article, in a lot of ways. That when a single person is writing an article about a scientific study, they can pick and choose which bits of information they want to include or talk about. It does not necessarily reflect the findings of the study, it’s one person’s perspective. So, does that mean my article I am in the middle of writing right now is also just one person’s opinion and perspective of the paper? Yes, absolutely it does. But does that make one article more right than the other? Possibly, but it depends on a lot of different factors, like the authors biases, or the authors motivations for writing the article.
“a carefully and well-planned vegan diet can provide all the nutrients needed for good health”
Building on that point, take me for example, I am vegan for ethical reasons. So, is it possible I am writing this article because I want to defend my position for following a vegan diet? Absolutely it is possible. But this is the reason we should not be using a single scientific paper as justification or evidence that one dietary pattern is healthy or not – people are subject to biases and influence. This is exactly what the scientific process is all about. We conduct studies more than once, we have people form outside the study carefully evaluate it, and we continue to build on the evidence with more studies that are bigger and more robust. And only with a lot of studies of high quality, do we start to form any conclusions at all about what a healthy diet is. This study itself states that there is a lack of evidence around plant-based diets in adults, let alone children (the focus of this study). The study goes on to say further work is required to determine the reason behind vegan kid’s low bone density – because this study cannot determine what caused the low bone density, only that it exists. It may not even be the fact they are eating a vegan diet.
What does the evidence actually say about plant-based and Vegan diets?
So, what does all the available evidence say about plant-based diets in kids? The position of Dietitians Australia, the leading body for nutrition and diet in Australia says: “a carefully and well-planned vegan diet can provide all the nutrients needed for good health”. This position in based on all the available evidence that has been carefully evaluated by multiple dietitians at Dietitians Australia. This position continues to be refined and evaluated based on any new evidence or studies that come out.
There are many different ways to achieve a healthy diet, there is no single, definitive diet you can eat that will lead to the best health results for everyone, but they may be one that works best for you.
Although this study is a strong study of high-quality, performed well and minimized bias, it cannot give us clear and definitive conclusions. We need to look at the evidence as a whole, not just single studies. Some studies will have the same findings, some likely will have different results – but that’s fine. Like I said, that is what the scientific process is about – we need a lot of robust, strong studies to draw conclusions on topics. Even then, a science like nutrition often cannot come to clear conclusions, not like some other sciences with clear ‘yes’ and ‘no’ answers to questions. In nutrition we know there are many different ways to achieve a healthy diet, there is no single, definitive diet you can eat that will lead to the best health results for everyone, but they may be one that works best for you.
So, what can we actually take away form this study? That there needs to be further research into this area. This is a strong study that highlights both positives and concerns surrounding a vegan diet. Plant based diets are healthy, with clear benefits for people’s health, the environment and for animal welfare. But they are not without their concerns with regards to calcium intake and bone health in kids. This is just one study, though, and we need to continue to build the evidence and find out if it is a plant-based diet that is causing the low bone density, and if so, why it’s causing it. Remember, this study was only looking at kids in one country, and does not mean this is true of kids eating plant-based diets in other parts of the world.
- Desmond MA et al. Growth, body composition, and cardiovascular and nutritional risk of 5- to 10-y-old children consuming vegetarian, vegan, or omnivore diets. Am J Clin Nutr. 2021;113:1565–1577
- Dinu M, Abbate R, Gensini GF, Casini A, Sofi F. Vegetarian, vegan diets and multiple health outcomes: a systematic review with meta-analysis of observational studies. Crit Rev Food Sci Nutr 2017;57:3640–9.