As a vegetarian and later a vegan, I have encountered many people who believe that only meat can make us grow big and strong. A group of my students even expressed genuine astonishment that I had survived from the age of 13 without eating meat.
The truth is that in order to grow and thrive, a human body simply needs adequate nutrients. Enough energy overall, enough protein overall, enough of the essential fats and amino acids, enough of the vitamins and minerals we need, enough dietary fibre.
We don't have to eat meat to get adequate nutrition at any stage of life. All of our nutritional needs can be met in a vegetarian (or vegan, with B12 supplementation) diet. But any diet should be properly planned; we all need to have access to a variety of nutritious foods in sufficient quantities.
In some cases, adolescents who become vegetarian may face social challenges - for example, their home or school may not provide nutritious vegetarian meals or snacks. Others may have inadequate access to food for financial reasons. These things are bad and we should fight against them. But the problem is not the choice of diet.
There are some nutrients that may need extra attention for young vegetarians. For example:
- Iron
Iron is a concern for non-vegetarians also; many children and adolescents do not get enough regardless of their dietary pattern. However, non-haem iron from plant sources is less bioavailable than haem iron found in meat. To mitigate this, plant sources of iron (such as pulses and nuts) should be consumed alongside a source of vitamin C (such as capsicum, strawberries, kiwifruit, pineapple, lemon juice etc etc) which greatly improves the absorption of iron.
- DHA (omega 3 fatty acids)
Although essential fatty acid DHA can be produced from ALA which is present in walnuts, flaxseeds and a few other plant foods, the conversion is not very efficient and is even less efficient in babies and children, so children who don't eat oily fish may benefit from taking DHA supplements sourced from algae.
- Vitamin D
People who don't spend much time outdoors in the sun may benefit from vitamin D fortified foods or supplementation. Vitamin D is especially important for people who are growing because it's required for the absorption of calcium which builds our bones.