When I did Slimming World a few years ago I had Quark, it's not great, a bit like cottage cheese I suppose, but we were told to use it instead of marge or butter I gave up on it in the end as I didn't like it, but it's a matter of personal choice. Give it a try and you never know, you might be a convert.
A recipe idea I got from SW for a kind of mousse using quark. Put a pot of quark in a large mixing bowl. Make a jelly using quarter of a pint of water and water flavouring. Leave it to cool. Slowly, stirring all the time, add the liquid jelly to the quark. Leave to set. Its delicious!
I used to eat it all the time on SW
I used to mix it with a spoonful of jam/lemon curd(As a sin)or a tsp of drinking powder and it tasted like cheesecake...Wouldn't think you can have it on CD hough...maybe as you are on higher plans...you would have to check