Lots of good advice from all of you, thanks. Very confused about carbs though. I was looking at a website showing carb content of various foods and a lot of it doesn't make sense to me. For example, white bread (which I always thought was the arch enemy) has fewer carbs than a seeded loaf that is full of protein-filled seeds! I also understand that Pilsner lagers have a relatively benign effect on blood sugar yet I'm told that alcohol is also an arch enemy, particularly beers and lagers. And finally, "carbs" measurements seem to be different to the actual amount of sugar/wheat etc in a particular type of food.
I am baffled by it all.