This is what I found online:
'Wholemilk yoghurt contains 3.4 per cent fat; low-fat yoghurt contains 1-2 per cent fat; and diet, virtually fat-free yoghurt contains 0.2 per cent fat or less. Greek yoghurt has a much thicker consistency, giving a more concentrated yoghurt with a fat content of 8-10 per cent.'
Seona