I think your meal was just fine. Just think how small two bowls of salad become after they're chewed well. It all depends for me-some foods, I can eat quite a bit-but others, just a few bites and I'm full. I think it does depend on how much space the chewed food takes up. The thought that you can now eat two bowls of salad-may be quite frightening when you think that your tummy is only the size of an egg-but really, as long as you chew well and take your time-that salad will not take up much space-and think how much you'ld have eaten in your old life.
They're isn't any guidelines, at least as far as I know, about calories after bypass. Of course, you can't eat lots of high calorie foods-but salad??? Keep the dressing low fat or no fat-and I think it's a good choice.