Plant-based nutrition

Vegetarian and vegan diets

A well-planned vegetarian or vegan diet can meet nutritional needs across life. Balance depends on the foods, fortification and supplements used—not simply the “plant-based” label.

Reviewed August 2026

Common eating patterns

Lacto-ovo vegetarian: includes dairy foods and eggs, but not meat, poultry or fish.
Lacto-vegetarian: includes dairy but not eggs, meat, poultry or fish.
Ovo-vegetarian: includes eggs but not dairy, meat, poultry or fish.
Vegan: excludes animal-derived foods, including dairy, eggs, meat and fish.
Pescatarian: includes fish and seafood and is plant-forward, but is not usually classified as vegetarian.

Benefits and challenges

Vegetables, fruit, legumes, wholegrains, nuts and seeds can provide fibre, folate, potassium, magnesium and protective plant compounds. Replacing fatty meats with legumes, tofu, nuts and seeds can support heart and metabolic health. Poorly planned diets, however, may be low in vitamin B12, iron, calcium, iodine, vitamin D, zinc, omega-3 fats, protein or total energy.

A simple balanced meal

Aim for ½ vegetables or salad, ¼ protein-rich food and ¼ wholegrain or starchy carbohydrate. Add a calcium-rich food and a suitable amount of olive or canola oil, nuts, seeds, tahini or avocado.

Protein across the day

Include tofu, tempeh, beans, lentils, chickpeas, textured vegetable protein, soy mince, edamame, nuts or seeds at main meals; eggs and dairy foods are options for those who include them. A variety of plant proteins across the day supplies all essential amino acids. “Complementary” proteins do not need to be combined at every mouthful or meal.

Key nutrients

Iron: choose legumes, tofu, tempeh, seeds, wholegrains and fortified cereals. Add vitamin C-rich fruit or vegetables to improve non-haem iron absorption, and keep tea and coffee away from iron-rich meals if stores are low.
Vitamin B12: vegan diets require a reliable fortified source or supplement. Some vegetarians also need one. Seaweed, mushrooms, fermented foods and nutritional yeast are not reliable unless the label confirms added B12.
Calcium: use dairy foods or calcium-fortified plant milk, calcium-set tofu and verified fortified alternatives. Check plant-milk labels: calcium and protein vary widely, and many almond, oat and coconut drinks are low in protein.
Iodine: needs can be harder to meet without dairy, eggs or seafood. Iodised salt or an appropriate supplement may help, but kelp products can provide unpredictable excess iodine.
Vitamin D: sunlight exposure, skin pigmentation, clothing, season and location affect status. Fortified foods or supplements may be needed after individual assessment.
Zinc: include legumes, tofu, tempeh, nuts, seeds and wholegrains; soaking, sprouting and fermenting can improve availability.
Omega-3: include chia, ground linseed, hemp seeds, walnuts or canola oil. An algae-derived DHA/EPA supplement may be considered individually.

Enough energy matters

Very high-fibre, bulky meals can fill the stomach before enough energy and protein are eaten. This needs particular attention for infants and children, pregnancy and breastfeeding, older adults, athletes, people with poor appetite or illness, and people recovering from an eating disorder. Energy-dense foods can be useful and should not be unnecessarily restricted.

When to seek advice

An Accredited Practising Dietitian or doctor can help with pregnancy, infant or child feeding, multiple exclusions, gastrointestinal disease, fatigue, weight or growth concerns, eating-disorder recovery, high training loads, or uncertainty about supplements. Blood tests may be appropriate based on symptoms and risk. Do not self-prescribe high-dose iron or iodine.