Meeting Your Macronutrient and Micronutrient Needs on a Vegetarian Diet

Hi I’m Sammy,

Your Good Farm in-house nutritionist. Here to bring you essential information on nutrition, diet and permaculture gardening - in a bite size, easy to understand, science-backed way.

Meeting Your Macronutrient and Micronutrient Needs on a Vegetarian Diet

People choose vegetarian diets for many reasons. For some, it is an ethical decision. Others are motivated by environmental concerns, religious beliefs, health goals, or simply because they do not enjoy eating meat.

The environmental discussion is often more nuanced than it first appears. Industrial livestock systems can place significant pressure on the environment, but not all animal farming is the same. Regenerative farming systems aim to improve soil health, increase biodiversity and, in some cases, sequester carbon. Many regenerative and mixed farming systems rely on animals moving across the landscape to support healthy ecosystem function.

Equally, some large-scale monocropping systems that produce soy, wheat, corn and other commodity crops can contribute to soil degradation, biodiversity loss and heavy pesticide use. Nature was never intended to be a one-species show. Strength and resilience in natural systems rely on diversity.

As with so many aspects of health, nutrition and environmental sustainability, there is rarely a simple black-and-white answer.

When assessing any dietary pattern, it is helpful to look through the lens of nutrient density and bioavailability. Nutrient density refers to the amount of protein, vitamins, minerals and beneficial compounds contained within a food. Bioavailability refers to how easily those nutrients can be absorbed and utilised by the body. Both deserve consideration when choosing a dietary pattern.

A well-planned vegetarian diet can be nutrient-dense, but it generally requires more planning than a diet that includes animal foods. There are several nutrients that become worth paying closer attention to once meat is removed from the plate.

What is a Vegetarian Diet?

A vegetarian diet excludes meat but may include eggs, dairy products and honey.

There are several variations. Some vegetarians consume eggs and dairy, while others avoid them. Pescatarians include seafood but exclude meat. Vegans avoid all animal-derived foods, including eggs, dairy and honey.

Seafood is often viewed as a more sustainable option than land-based animal foods. While this may be true in some cases, sustainability varies enormously between species and production methods. Well-managed fisheries exist alongside significant issues such as overfishing, habitat destruction and bycatch. It is also worth noting that our oceans now contain a growing burden of pollutants, including heavy metals, microplastics and other environmental contaminants, some of which can accumulate in larger predatory fish. As a result, a seafood choice may score well from a sustainability perspective while still raising questions from a contaminant perspective.

Protein

Protein is usually the first nutrient people think about when discussing vegetarian diets. While protein intake can certainly be adequate, protein quality and amino acid composition also deserve consideration.

Protein is made up of amino acids, which are required for muscle maintenance, hormone production, neurotransmitter synthesis, immune function and tissue repair. Despite the attention protein receives, it is often one of the nutrients that can fall short in both adults and children. This can be particularly relevant for vegetarians, growing children, older adults and selective eaters.

Many plant foods contain lower amounts of one or more essential amino acids compared with animal foods, making variety increasingly important. Digestibility also differs, with animal proteins generally being more readily digested and absorbed than plant proteins. This is another example of why bioavailability deserves consideration alongside nutrient content.

Eggs and dairy are valuable additions to a vegetarian diet because they provide highly bioavailable protein and a complete amino acid profile. For those following a vegan diet, legumes, lentils, tofu, tempeh, edamame, nuts, seeds and whole grains become important. Combining different plant protein sources across the day can help provide a broader range of amino acids. Common examples include beans and rice, lentils and whole grains, or oats topped with nuts and seeds.

Traditional preparation methods such as soaking, sprouting and fermenting help improve digestibility and nutrient availability. Foods such as sourdough bread, tempeh and properly prepared legumes have been staples in traditional diets for generations.

If you would like to learn more about protein requirements, protein quality and how much protein is needed, refer to our previous protein series here.

Fats

Fats play important roles in hormone production, brain function, cell membranes and the absorption of fat-soluble vitamins.

Extra virgin olive oil, avocado, olives, nuts, seeds, eggs and dairy products can all contribute valuable fats to a vegetarian diet.

One pattern I often see is people replacing meat with a greater reliance on packaged vegetarian foods. These foods are often made with refined vegetable oils such as soybean, sunflower, canola or safflower oil. As intake of these foods increases through snacks, dips, convenience meals and meat alternatives, omega-6 fat intake can rise substantially. At the same time, intake of foods that naturally provide the long-chain omega-3 fats EPA and DHA, such as seafood, eggs and certain animal foods, may decline. Together, these changes can create a less favourable balance between omega-3 and omega-6 fats. A similar pattern is often seen with gluten-free diets, where foods are sometimes assumed to be healthier simply because they are gluten free, despite many gluten-free convenience foods also being highly processed.

Rather than focusing solely on increasing omega-3 intake, it can be equally worthwhile to consider reducing unnecessary sources of omega-6 fats. Making foods such as hummus at home, choosing products made with extra virgin olive oil where possible, and limiting highly processed foods can help create a more beneficial balance.

If you would like to learn more about healthy fats, cooking oils and omega-3 fats, refer to our previous series on fat here.

Carbohydrates and Fibre

One area where vegetarian diets often shine is fibre.

Legumes, vegetables, fruit, nuts, seeds and whole grains generally feature more prominently in vegetarian diets than in the average Australian diet. This often translates to higher fibre intake and greater diversity of plant foods.

Fibre is a type of carbohydrate that we cannot fully digest ourselves, but many of our gut microbes can. In this way, fibre acts as nourishment for the microbes that reside within the digestive tract.

If you would like to learn more about carbohydrates and the different types of fibre, refer to our previous carbohydrate series here.

Micronutrients Worth Paying Attention To

Vitamin B12

Vitamin B12 is found almost exclusively in animal foods.

Low B12 levels can affect energy, mood, memory, concentration and nervous system function. Because deficiency often develops gradually over many years, symptoms are frequently mistaken for stress, ageing or a busy lifestyle. Left untreated, long-term deficiency can result in neurological damage, some of which may not be reversible.

Those following a vegan diet require vitamin B12 supplementation. Vegetarians should periodically assess both dietary intake and B12 status, particularly if eggs and dairy are consumed only occasionally.

Iron

Iron is one of the most common nutrients requiring attention in vegetarian diets.

Plant foods contain non-haem iron, which is absorbed less efficiently than the haem iron found in meat and seafood. Useful vegetarian sources include lentils, legumes, tofu, pumpkin seeds, tahini and dark leafy greens.

If haem iron foods are not being consumed, improving iron absorption becomes increasingly important. Pair iron-rich foods with vitamin C-rich foods such as citrus, kiwi fruit, berries or capsicum, and avoid drinking tea or coffee with meals, as they can reduce iron absorption.

If you would like a deeper dive into iron and strategies to improve absorption, refer to our previous article on iron here.

Zinc

Zinc supports immune function, skin health, fertility, growth and wound healing.

Good vegetarian sources include pumpkin seeds, legumes, nuts and whole grains. However, zinc from plant foods is generally less bioavailable than zinc from animal foods because naturally occurring phytates reduce its absorption. For this reason, zinc requirements may be slightly higher in predominantly plant-based diets.

Traditional preparation methods such as soaking, sprouting and fermenting can help improve zinc availability by reducing phytate content.

Choline

Choline is one of the most overlooked nutrients in nutrition. It is essential for liver function, methylation, cell membrane integrity and brain health, and plays a particularly important role during pregnancy and early childhood.

Eggs are by far the richest vegetarian source of choline. Smaller amounts are found in soy foods, legumes and cruciferous vegetables such as broccoli and Brussels sprouts, although meeting requirements from plant foods alone can be challenging. For those following a vegan diet, careful planning and, in some cases, supplementation may be required.

Omega-3 Fats

As discussed in the fats section above, omega-3 fats deserve particular attention in vegetarian diets. While plant foods such as chia seeds, flaxseeds and walnuts provide ALA, conversion into the more biologically active long-chain omega-3 fats EPA and DHA is often limited.

For those who consume seafood, oily fish remain one of the richest dietary sources of EPA and DHA. For those who do not, an algae-derived omega-3 supplement provides a direct vegetarian source of these important long-chain fats.

If You or Your Child Simply Doesn't Like the Taste of Meat

Not everyone avoids meat for ethical, environmental or religious reasons. Sometimes it simply comes down to taste, texture or preference.

If you or your child do not enjoy eating meat but are open to food-based nutritional supplements, there are several ways to increase nutrient density without dramatically changing the diet. Liver powder can be added to soups, casseroles, sauces, dahls and curries. Bone broth can be used in these dishes as well, or as the cooking liquid for grains. Collagen can be added to smoothies, porridge and yoghurt. Liver capsules can also provide an alternative for those who can swallow tablets. Oyster capsules are another food-based option, providing a concentrated source of highly bioavailable zinc, a nutrient that can be difficult to obtain in adequate amounts when meat intake is low.

In many cases, it is easier to prevent a nutrient deficiency than it is to correct one. Consistent additions of nutrient-dense foods can help support intake of nutrients such as iron, vitamin A, zinc, B12, choline and glycine over time. This can be particularly valuable during periods of rapid growth, such as adolescence, when zinc requirements increase to support growth, immune function and development.

If you suspect a nutrient deficiency, such as iron deficiency, it is best to consult an integrative health professional and, where appropriate, undertake testing before commencing supplementation. Minerals do not work in isolation. Taking a nutrient that is not needed can sometimes create imbalances elsewhere or, in some cases, become harmful when taken in excess.

Just because a herb, vitamin or mineral is considered "natural" does not mean it is without effects. Like medicines, nutrients can have benefits, risks and interactions. If testing is not immediately available, focusing first on nutrient-dense foods and food-based supplements is often a sensible starting point while seeking further guidance.

Good Farm Shop Picks

Here are a few of my favourite vegetarian Good Farm meals

Pumpkin Risotto is the ultimate comfort food. Because the rice has already been cooked, cooled and then reheated, it contains resistant starch, which helps nourish the beneficial microbes in our gut. I like to serve it with two fried eggs and a side of leafy greens to help with my protein intake.

Butter Tofu Curry offers a valuable source of complete plant protein from quality non-GMO tofu. Pair it with sautéed spinach and a squeeze of lemon to further support iron intake and absorption.

Mediterranean Veg and Lentil Pie combines legumes, which are a complete plant protein, along with plenty of vegetables, fibre and a range of beneficial plant compounds.

Whether you choose to eat meat or not, the same nutritional principles apply. Build your diet around nutrient-dense whole foods, understand where key nutrients are found and consider their bioavailability. These simple principles provide a strong foundation for long-term

References

Clinical Naturopathy. 2nd ed. Elsevier; 2020.

Academy of Nutrition and Dietetics. Position of the Academy of Nutrition and Dietetics: Vegetarian Diets. Journal of the Academy of Nutrition and Dietetics. 2016.

National Health and Medical Research Council. Australian Dietary Guidelines. 2013.

National Institutes of Health Office of Dietary Supplements. Fact Sheets for Health Professionals: Vitamin B12, Iron, Zinc, Choline and Omega-3 Fatty Acids.

World Health Organization. Healthy Diet Factsheet.