Food is freshest, and of the highest quality through the large supermarket shelves. No-one else can compete with their quality control and the speed of movement from farm to shelf. They also have the highest turnover, so food ingredients have rarely been on the shelf long, and only a very few ever reach their best before dates.
More unusual items can often be obtained at ethnic supermarkets and health food shops.
Fresh fruit and vegetables have the highest food values and the fewest additives. Buy them in quanities you can use quickly and store them at the correct temperature.
Most should be kept cool and dry.
When you look at tinned foods, select those with the fewest added ingredients. There are hundreds of additives designed to modify the texture, appearance and taste, which do nothing for the food value but whose health risks are as yet unknown. There is no need to avoid them altogether, but it might be wise to restrict their use as far as possible.
Many tinned foods have high salt and/ or sugar levels and these are best avoided.
Some breakfast cereals may also have excessive levels of salt and sugar and these should be avoided.