More out of curiosity than anything, i would like to know what exactly happens metabolically if i indulge in some pasta, or bread or something else??? a dear friend of mine does BTD and swears that she follows at 80/20 or so, and still loses and feels great...thoughts? thanks!

Lots of good information posted on this that you might look through and others will add to this thread.

Here is a place to start: http://www.dadamo.com/cgi-bin/Blah/Blah.pl?b-GC/m-1142920713/

A real general answer is that there are a range of different effects.
Some foods cause mucous and congestion.
Some foods interfere with proper immune response.
Some foods hurt the digestive system, causing IBS, pain or bloating.
Some foods cause insomnia and/or restlessness.
Some foods affect the emotional balance, showing up as depression or irritability.
Some foods show no obvious reaction and work invisibly over years to later appear as a serious disease.

Adding to Victoria's List:
Some cause dry eyes, leading to bouts of excess tearing if the eyes get too irritated.
Some cause muscle and /or joint pain.
Some cause weight gain.

Yes, Joe, it's so true.

And some of the reasons that people sometimes feel mysterious symptoms that appear for a while, or off and on, after starting to eat right is like this (as I see it):

After a lifetime of eating foods that do some or all these things, our bodies can become somewhat non-responsive to them , at least overtly.  When we finally remove those toxic foods, the body gradually begins to wake up again on all levels and we can begin to see the damaging effects of how we have been eating and living.  It's different for different people.  It's different for Non-Secretors than for Secretors.  It's different for younger people than older.  And different for people who have already begun to see the manifestation of chronic disease than it would be for healthy or 'apparently healthy' people.

dry eyes and very sluggish is how I feel but I think everyone is very different.

tired, pain, breathing, nose sinus, big belly, puffiness, more craving, depression, hopelessness, sleep and bathroom issues.. I think this is enough.. you decide...

the good part about BTD i no longer need to see a doctor when I don't get why I just gained 10 pounds and feel all the above.. all I need is my friend to ask, what did you eat last night?.. end of all questions.. answer self evident..    

you've eaten *avoid* foods.....