So, I am in a condition of severe caloric deficit, with my fat stores being accessed and burned. This is a condition our ancient ancestors would be in on a regular basis. In my foray to the past I am joining them, albeit in an artificial, contrived way, but essentially identical. You would think that in a period of scarcity the body would want to slow things down to conserve energy. That it does when scarcity becomes total, real starvation. This was the case in the 1944/45 Minnesota Starvation Experiment conducted by the (increasingly) infamous Ancel Keys. The volunteers were fed a typical American diet consisting mainly of potatoes, rutabaga swede, turnips, bread and macaroni about 1500 calories per day (yeah, me too!). Their basal metabolism plummeted and they felt cold in the middle of summer and obsessed about food to the exclusion of ANYTHING else. It’s important that it’s understood the difference between scarcity and starvation, for in conditions of scarcity the basal metabolic rate goes UP, not down. Starvation is the last resort to keep the body alive, so metabolism tanks. Think about it. You are in your primitive shelter with nothing to eat. If your metabolic rate falls you feel like crap and don’t want to move; the last thing you need when you should be getting up off your backside and getting out there to hunt for food. But what really happens is the body ramps up the metabolic rate so you feel good and motivated. Jason Fung says it goes up by some 14% and points to studies that confirm this. Does it? Well, I haven’t a clue, as the evidence I have is empirical, however, what I can say is that my enthusiasm to exercise has gone through the roof - hence me going out in a flying gale on Sunday and cycling 17 odd miles when anyone sane would be sat in front of the television.
While we are on the subject of fasting there often is the bogeyman in the background - muscle mass. More often than not whenever the subject of rapid weight loss crops up, it is often followed by dire warnings of lean tissue loss. This has never made any sense to me. Even the leanest amongst us will have many thousands of calories stored as fat, so why would nature sacrifice precious muscle when you need it most and leave fat energy in storage? The prime example of this myth is the story of Scotsman Angus Barbieri who fasted for 382 days under medical supervision. His weight decreased from 456 to 180 lb and was able to move around normally. Hardly an example of muscle loss. This to me is a prime example that needs the application of Occam’s razor!
Update. Yesterday swam 50 lengths and cycled 22 miles. Exercise calories burned 1495.
