Alsbaby, when a food doesn't have a free food allowance (choc, crisps, cake, drinks etc) it's technically irrelevant about the fat v sugar amounts . . . it'd be a straight 1 syn for every 20 cals.
However, in this case, I assume Kelly selected 'yoghurt' as the free food on the SW Syns Calculator which, has a sneaky jiggery pockery way of calculating depending on a number of ingredients, it comes out as less syns.
It does seem confusing but just think, if you overestimated you syns for things like this, it would be in your favour at the end of the day
