Feeding children on a plant-based diet

Major dietetic associations have concluded that appropriately planned vegetarian and vegan diets are suitable for all stages of life, including infancy and childhood.

The words doing the work are "appropriately planned". Children have higher requirements relative to body size, smaller stomachs, and less tolerance for deficiency.

This article is orientation. Anyone raising a child on a fully plant-based diet should have input from a registered dietitian or paediatric professional, and this is not a formality.

The specific risks

Energy density. The main practical issue. Children have small stomachs and high energy needs relative to size, and plant foods are bulky.

A child filling up on vegetables and wholegrains may not obtain enough energy, and inadequate energy in childhood affects growth.

The fix is deliberate energy density: nut butters, tahini, avocado, oils, full-fat plant alternatives, dried fruit, and not over-restricting fat.

Very high-fibre diets in young children can be a problem for this reason, which is the opposite of adult advice.

B12. Non-negotiable and the risk is highest here. Cases of severe deficiency in infants of unsupplemented mothers are documented and the consequences can be permanent.

Breastfeeding mothers must supplement. Children must receive B12 from supplements or reliably fortified foods, in age-appropriate amounts.

Iron. Requirements are high in infancy and adolescence, and deficiency affects cognitive development. Plant iron is less well absorbed.

Testing is worth doing rather than assuming.

Calcium and vitamin D, for bone development during the period when peak bone mass is established.

Iodine, important for cognitive development and easily missed when dairy is removed.

Zinc, required for growth and immune function.

Omega-3, particularly DHA, for brain and eye development. An algal supplement is the reliable route.

Protein, generally adequate if the diet contains regular legumes and soy foods, and worth attention in fussy eaters.

Infants

Breast milk or appropriate infant formula for the first year, with the mother supplementing B12 if breastfeeding on a plant-based diet.

Soy-based infant formula is available and should be used only on professional advice, since it is not appropriate for all infants. Other plant milks are not suitable as a main drink under one year.

Weaning follows the same general principles as any diet — introducing a range of textures and flavours from around six months — with deliberate attention to iron-rich foods and energy density.

Do not give unmodified plant milks as a main drink before one year. After one year, fortified soy milk is the closest nutritional match to cow's milk among plant options.

Rice drinks are not recommended for young children because of arsenic content, and several countries advise against them under five.

Toddlers and young children

The fibre and volume issue is at its sharpest here.

Practical measures: include fat generously, use smooth nut butters, offer refined as well as wholegrain foods, and offer frequent small meals and snacks rather than three large ones.

Do not restrict fat in children under two. Full-fat versions of plant alternatives, and oils in cooking.

Whole nuts are a choking hazard under five — use butters and ground nuts.

Older children and adolescents

Adolescence brings a growth spurt and substantially increased requirements, particularly for energy, protein, iron and calcium.

Iron deficiency in adolescent girls is common in all dietary patterns and worth testing for.

Adolescents also frequently adopt plant-based eating independently, sometimes without knowledge of what needs replacing, and sometimes as a socially acceptable route to restriction.

That last point deserves care. Where a young person adopts a restrictive diet alongside weight loss, increasing exercise, or preoccupation with food, that warrants attention rather than accommodation. Plant-based eating is not disordered eating and it is sometimes used as cover for it.

Practical strategies

Include a protein source at every meal and snack.

Use fortified foods deliberately — fortified plant milk, fortified cereals — and check the labels, since unfortified varieties are common.

Do not rely on the child's preferences alone. Children in any dietary pattern will eat carbohydrate and avoid vegetables given the choice.

Offer foods repeatedly. Acceptance of new foods frequently requires many exposures, and the standard advice not to pressure but to keep offering applies.

Family meals, with everyone eating the same thing, which is associated with better dietary quality across the board.

Monitor growth, which is the most important single indicator. Regular weight and height measurement against growth charts detects a problem earlier than anything else.

Get professional input

Genuinely. Not because plant-based diets are dangerous, but because the margin for error is smaller in children and because a dietitian will identify gaps you will not.

What to ask for: a full dietary assessment, guidance on supplementation, and a plan for monitoring growth and, where indicated, blood tests.

Ask your GP or health visitor for a referral, and look for a dietitian with paediatric experience.

The reassurance

Children are raised on plant-based diets successfully across the world and have been for a very long time.

The problems arise from inadequate planning rather than from the diet itself, and the specific things that need attention are known and addressable.

Supplement B12, keep energy density high, include legumes and fortified foods daily, monitor growth, and get professional input.

Anyone feeding an infant or child a fully plant-based diet should seek advice from a registered dietitian. Do not delay medical assessment if a child is not growing as expected, is persistently tired, or is losing weight.