Vegetarian and vegan diets: how to plan them well

What types of vegetarian diet are there?

Vegetarian diets include several patterns, depending on which animal-based foods they include. A lacto-ovo vegetarian diet excludes meat, fish and their derivatives, but includes eggs and dairy. A lacto-vegetarian diet also excludes eggs. An ovo-vegetarian diet includes eggs but excludes dairy. A vegan diet, also called a strict vegetarian diet, consists entirely of plant foods and excludes honey. See “Raw vegan diet”.

In adults, all these patterns are nutritionally adequate when well planned, according to the Academy of Nutrition and Dietetics [1]. They may also offer long-term cardiometabolic benefits [1]. What differs is which nutrients are covered by food and which need more attention or supplementation. Pregnancy, breastfeeding and childhood have specific guidance, which we cover below.

How to get enough protein without meat

This is the question we hear most often in consultations when someone gives up meat. A common myth says plant protein is “incomplete” and that you need to combine pulses and grains in the same meal. You do not. A varied plant-based diet provides all the essential amino acids over the course of the day, as long as you eat enough energy to meet your needs [1].

In practice, include a protein-rich food at each main meal [1]. Options include pulses (chickpeas, lentils, beans and peas), tofu, tempeh, textured soy, edamame, seitan, nuts and seeds. AESAN recommends at least four servings of pulses a week for the general population, building up to daily intake [2]. Eating them every day is sensible on a vegetarian diet. Eggs and dairy can contribute, but should not push pulses off the plate. If you eat dairy, choose plain, unsweetened options, up to three servings a day. If you also want to lose weight, see our guide to the vegetarian diet for weight loss.

Why is vitamin B12 essential, and how do you supplement it?

Vitamin B12 (cobalamin) is not found in plant foods. Fermented foods such as tempeh, nori seaweed, spirulina, chlorella and unfortified nutritional yeast are not reliable sources [3]. This is a common and delicate misconception. B12 levels can be low for a long time without noticeable symptoms while the deficiency progresses [3].

That is why you need a B12 supplement if you are vegan. Fortified foods can help, but they do not replace a supplement [1] [3]. Supplementation is also advisable if you are lacto-ovo vegetarian. One glass of milk and one egg a day provide only about two-thirds of the recommended daily amount [3].

What about the dose? Active B12 absorption becomes saturated at small amounts per dose. With larger doses, around 1% is also absorbed by passive diffusion, which allows less frequent dosing [3]. Cyanocobalamin is the form most often used in supplements because it is stable [3]. Your doctor or dietitian-nutritionist sets the dose and frequency according to your needs.

How can you get enough iron and calcium without meat or dairy?

Another common myth is that giving up meat causes anaemia. The iron in plant foods, known as non-haem iron, is absorbed at widely varying rates. Absorption ranges from 1% to 23%, depending on a person’s iron stores and what they eat with the meal [3]. Vitamin C improves absorption, while tea and coffee reduce it [1]. In practice, pair pulses with raw pepper, tomato, lemon, strawberries or kiwi.

Calcium is not found only in dairy. EFSA sets the general reference intake at 950 mg a day for adults aged 25 and over. Calcium from tofu set with calcium salts and from fortified plant-based drinks is absorbed at a rate similar to calcium in cow’s milk, around 30% [3]. Low-oxalate leafy greens such as kale, turnip greens and pak choi reach about 50% [3]. Calcium from white beans, almonds, tahini and figs is less well absorbed, at around 20% [3]. Spinach and chard contain plenty, but their oxalates mean only about 5% is absorbed [3]. If you are vegan, aim for at least two or three servings a day of foods that are rich in well-absorbed calcium [1].

Omega-3 and iodine when you do not eat fish

Oily fish provides the long-chain omega-3 fats EPA and DHA. A plant-based diet provides their precursor, alpha-linolenic acid (ALA). It is found in ground flaxseed, chia, hemp seeds, walnuts and their oils. Healthy adults are advised to include these sources regularly [1]. During pregnancy and breastfeeding, your team assesses whether you need a microalgae-derived DHA supplement [3]. Your doctor or dietitian-nutritionist decides on the DHA supplement. If you take anticoagulants or antiplatelet medicines, speak to your doctor before taking omega-3 supplements.

Iodine is needed for normal thyroid function, and plant foods provide little unless they are seaweeds. Iodised salt is therefore the simplest way to get enough [1]. Brown seaweeds such as kombu and kelp have the opposite issue: their iodine content can be very high and variable, so limit how often you eat them [1]. Avoid seaweed during pregnancy and breastfeeding. Your midwife or doctor assesses whether you need an iodine supplement.

What mistakes do we commonly see in consultations?

“I’ve stopped eating meat but I still eat the same way.” “I’ll take B12 if my blood test shows it’s low.” We hear both almost every week, and both are straightforward to address.

The first leaves a meal unbalanced. Pasta with tomato, rice with vegetables or a cheese sandwich, with no pulses or other protein source. Include a plant protein at each main meal to address this.

The second is more concerning, for the reasons explained above. Start the B12 supplement from day one.

We also often see two shortcuts. One is replacing meat with ultra-processed plant-based foods. Vegan burgers, sausages and cheeses often contain refined flours, less healthy fats and plenty of salt; a “vegan” label does not change that. The other, among people who eat eggs and dairy, is relying on cheese and eggs for everything. This increases saturated fat and leave less room for pulses.

Is a vegetarian or vegan diet safe for babies and children?

Well-planned vegetarian and vegan diets were considered suitable during pregnancy, breastfeeding and childhood too [3]. The more recent 2025 position paper focuses on adults and refers these life stages to specific guidance [1]. The European society for paediatric nutrition (ESPGHAN) recommends that vegan diets in childhood be followed only with supervision from a paediatrician and a dietitian-nutritionist [5]. Vitamin B12, vitamin D, iron, zinc, calcium, omega-3 fats, protein and energy all need to be covered. If recommended supplements are not taken, the consequences can be serious [5]. If you are vegan and pregnant or breastfeeding, B12 is essential and supplementation should be prescribed. Avoid restrictive diets in the postpartum period.

During complementary feeding, provide enough energy and nutrients with hummus, tofu, well-cooked pulses and mashed avocado [3]. You can offer ground nuts or nut butter from the start of complementary feeding. Do not give whole nuts before age 5. Avoid restrictive diets in childhood. Before one year of age, plant-based drinks do not replace breast milk or infant formula. Ask your paediatrician to monitor your child’s weight and height [5]. If you want support from the outset, a dietitian-nutritionist specialising in vegetarian and vegan diets can work with you and your paediatrician.