Is there a significant difference in the metabolic effect (or weight loss success or blood work improvement) between following the paleo eating plan at 80% versus following the paleo eating plan at 100%? I would suspect that zero-carb fans would argue yes. What I'm looking for is links to any academic research (if some has been done) or anecdotal evidence. I understand that theoretically there is a difference; but I'm wondering if the difference is statistically significant.
To clarify, I mean 20% to be one non-paleo meal (or day) per week that would likely include whole fermented grains, fruits and very little refined sugar. I'm not talking about eating a whole cake and fettucini alfredo. For example, should I allow myself a few "cattle" foods now and again or should I go completely hard core because if you're not 100% you're not actually paleo...?
Or let me ask a different question: if I'm going to "cheat" anyway, should I cheat big once a month, or just a little each day? Again, for example, what if I, once or twice a week, sneak a little teaspoon of rice or a bite of potato that I make for my non-paleo husband (when I'm having veggies and a broiled tuna steak), have I ruined my whole day?
Will a teaspoon of starches immediately cause me to switch back to burning sugar for fuel? Even though the rest of the day has been awesomely paleo?