I'm still finding it relatively easy and have lost 4kg since the beginning of January (haven't weighed myself for a week so here's hoping there's some more lost as well). However, the only reason I am succeeding is that I am, without fail, cycling 20 miles per day to earn myself 700-800 calories, plus walking the dog (good for another 100). I can't exist on just 1660 calories a day, but with the extra that I earn I am managing to finish each day with a reasonable calorie deficit (usually 400-500) which seems to be working. This is a deficit over the amount MyFitnessPal says I should eat to lose 1lb a week, which is I think a 500 calorie deficit over 'remain the same'.
What's been fascinating to me is realising HOW MUCH I was eating during the day in the run-up to Christmas. Not portion sizes particularly (they are still huge - I like my spuds and veg) but biscuits, nuts, other nibbles. I reckon I was taking on board at least 1000 calories per day in nibbles. And having lots of cake.
Thank God for bicycles!