The first few weeks (months) post-op are not at all indicative of what life with WLS is like. At this point, 16 mo post-op, I can eat and tolerate pretty much anything I want. The thing is, my tastes have changed so dramatically.
I don't crave garbage food anymore. For breakfast, I used to eat chicken biscuits, fries, muffins, and other junk. This morning, I had a bowl of greek yogurt with banana, berries, and granola, and it was the most delicious thing ever. I could force feed myself the garbage breakfast, but I wouldn't enjoy it.
Over time, you figure out your new anatomy and reshape your eating to accommodate it. Even now, almost a year and a half post-op, I'm still testing things out, seeing what works and what doesn't. That's the whole point of the surgery... to force you to make better choices.