There is plenty of fresh meat, fish, eggs, vegetables and fruit available, eating out in the tavernas, well there is a lot of grilled meats and fish, kebabs or souvlaki would be fine, there are stuffed peppers they are stuffed with feta cheese so quite a good choice. Baked feta is delicious, a greek salad is ok, you usually put the dressings on yourself.
You dont really get many cream based sauces they are usually tomato based. But at the end of the day you are on holiday, and its very easy to go straight back to the slimming world diets compared with diets which involve just having shakes etc, so just enjoy yourself!!