I probably don't need to confess to you that i haven't been on the strict regimen prescribed in "The Six Week Cure for the Middle-Aged Middle" all this time -- the kids came up from Texas for spring break, and we ate, drank, and made merry for six days. I still made every effort to keep my protein-consumption up, however. Then when they drove off southward again, i happily got back on the wagon.
Interesting thing, though: as the days passed on the three-shakes-and-one-meal protocol, my FitBit reported that my resting heart-rate steadily declined. I felt unfueled despite getting plenty of protein and being fat-and-ketone adapted. My metabolism was clearly being depressed.
Obviously in my case, amino acids from whey plus the BCAA supplement are not as beneficial as some people find them. Two days ago i went back to my "normal" pattern of coffee-with-collagen for breakfast and two ample meals per day, but still continuing the BCAAs, and my heart-rate is trending back upward.
I FEEL a bit thinner, though the scale hasn't been giving me any good news -- i presume the extra protein put muscle on me to offset any fat-losses i managed to achieve. Until our vacation starts, i'll pursue the VLC plan that seems to suit my body best, and avoid the little indulgences that i'm sometimes prone to treat myself to: staying away from the stray potato or rice i occasionally allow; having a pot of tea at the cocktail hour instead of wine; preferring LC recipes that don't include cheese or cream, because those ingredients (like nuts) seem to slow fat-loss for me.
Online diet-trackers having the shortcomings they do, i don't really know what kind of calorie-reduction i was looking at while experimenting with the 3shake1meal routine. I could have calculated it, but was too busy with host-duties and socializing to be motivated to do it. I ASSUME that i was just trying to be too active on too little food, although i didn't FEEL like i was going hungry at any point. To me, it just underscores the point that calorie restriction has many more downsides than are acknowledged by the CRaP* people: the body WILL slow down, no matter how much running around you do, if it thinks its fuel intake is suboptimal.
*. I love Dr. Fung's acronym for "calorie reduction as primary" -- it's almost as good as the expression "CICOpaths"!