A vegan is a strict vegetarian who does not eat any dairy products or eggs: most also do not eat honey. So vegan diets (as you may guess) will differ widely to normal diets, which may have consequences if you're on a weight management program.
A well-balanced vegan diet includes nuts, seeds, pulses, wholegrain and soya products for protein and essential amino acids. Vegetable oils - especially soya bean and rapeseed - deliver the two essential fatty acids (linoleic acid and a-linolenic acid) but there are other vitamins and minerals that can be hard to consume in large enough quantities.
In terms of Vegan diets and weight management, you will need to work harder to balance your bodies requirements for macro and micro-nutrients. It is the absence of any diary food or drink in the vegan diet that can sometimes cause problems. Milk and milk-based products, for example, are the primary sources of calcium in the UK. However, it can also be obtained from plant foods. Good sources include tofu, leafy green vegetables, watercress, dried fruit, seeds and nuts. Also food regulations require white bread to be fortified with calcium and some brands of soya milks also contain added calcium. People living in hard water areas may also find that that their drinking water contains significant amounts.
Making sure that levels of iodine are adequate may require more thought because it is not easy finding an alternative source as good as milk. Food and drinks made from seaweed can be an adequate substitute and some vegetables can be a good source if they were grown in iodine-rich soil.
Two important vitamins -vitamin B12 and vitamin D - are not found in any plant. Vitamin B12 - which mainly comes from meat, dairy products and eggs - plays a vital role in the manufacture of red blood cells and the maintenance of a healthy nervous system. As there is no natural substitute, the only alternative is to choose products that have been fortified with the vitamin. These include certain yeast extracts, veggie burger mixes, breakfast cereals, vegetable margarines and soya milks.
Fortified foods are also a way of delivering sufficient quantities of Vitamin D (found in oily fish, eggs and dairy products) but an outdoor life is also very helpful as this vitamin is synthesised by the skin when exposed to sunlight.