Hi Beachrunner: Here's an explanation for the weight gain that makes so much sense. I found it online looking up "weight gain after going off low carb diets" This is the quick summary...for every molecule of glycogen (stored carbs in the liver) there are 4 molecules of water attached. So, when you are on a low carb diet, you deplete your glycogen stores and also the attached water molecules...the reason you lose so much weight (water weight) when you first begin a low carb diet. Therefore, when you eat enough carbs (like that 3/4 cup of rice) for the body to replenish the glycogen stores, water is also retained.
This explains why the day following a "cheat" there is often 1-3lbs gained. I think this is also why the stabilization process is so important after reaching goal. It allows introduction of carbs back into the system slowly, over 6 weeks to help counter the water gain.
FYI: a serving of rice is usually 1/2 cup cooked. And while on MRC it is 1/4 cup cooked.