Veggies can make us feel stuffed because they take up so much room and are harder to break down. It's one of the many reasons we're encouraged to eat more of them.
That said, I highly disagree with the idea that the veggies are more nutritious than the chicken. The protein in the chicken is very, very important for your body. You need protein, especially if you are working out, as a basic building block of muscles and organs. Of course, balance is the important thing--you need protein and veggies and complex carbs, etc.--but you shouldn't negate the power of protein.
I'd say that you should try to stop when you are satisfied. If you find that you usually have the problem of eating your protein and then barely getting into your veggies before you are full, you should try to eat about half your protein and then get into your veggies so you are getting a balanced meal. Save the rest and, if you are hungry later, finish it.
Though veggies are important and are low in calories, it's not a good habit to get yourself used to eating until you are uncomfortably full. My nutritionist asked me to use a 1-10 scale of fullness. This quote from a
website explains it better than I can:
Quote:
When it comes time to lose weight, listening to your body is key. Especially when it is telling you that you are full.
A 1 to 10 scale can help you do that.
...
You know when your body is saying it's hungry, no doubt about that, but doctors say it's just as important to learn how to recognize when you're done eating, too.
It takes your brain a few minutes to catch up to your stomach, so you need to take your time eating and pay attention.
Here is a guide. Take a break every few minutes and ask yourself, just how full am I right now? If one is starving to death and 10 is so stuffed you are nauseous, you should try to stop eating when you are around six. So, by the time your brain catches up, you should be about a seven, which is satisfied, but comfortable.
One rule I've always had with myself is that if I feel hungry, I'll try to ignore it for a while, but if it doesn't go away, I offer myself the option of having some veggies. If I find that I'm very happy to eat veggies, then I assume I really am hungry. If the veggies don't sound good, I know it's probably a craving. So if you find that you are hungry after dinner and eating the rest of your dinner seems appealing, why not eat it? We aren't supposed to be hungry on SBD, and veggies are a great way to fill up.