I've used the sainsburys ones as well - v convenient for pp days. I suppose the trouble is you don't know what they've put into them, but taking the skin off gets rid of the fatty bit. I like the M & S deli chicken as well, but I noticed that it's marinaded in sugar, so probably not to be recommended if being strict. Hasn't done me any harm though, still lost, and it seems ok on the carb/sugar breakdown, so maybe it's not too terrible.