Dairy products
A family of foods made from milk (milk, yoghurt, cheese, fermented milks), the main source of calcium in Western diets, whose tolerance and value vary greatly between individuals.
Dairy products bring together foods with very different profiles: a milk, a yoghurt, a hard cheese and a cream have neither the same nutrient density, nor the same fat content, nor the same effect on digestion. Treating them as a single block is the first source of confusion in debates about them.
Their main value lies in calcium, present in a well-absorbed form, and in protein of good biological value. They also provide phosphorus, vitamin B12 and, in whole-fat products, fat-soluble vitamins.
Fermentation changes a lot. This is the most useful point in practice: yoghurts, fermented milks and matured cheeses contain markedly less lactose than milk, because the cultures have partly consumed it. Many people who digest milk poorly tolerate a yoghurt or a tomme cheese perfectly well, without having to cut out the whole family.
Two caveats are worth knowing. Cheese is the biggest source of salt in the diet after bread, something its “dairy product” image often makes people forget. And the insulin index of dairy is high relative to its glycaemic index: it triggers a greater insulin response than its carbohydrate content would predict, a parameter that mainly matters to people monitoring their blood sugar.