October 16, 2009
Weight - 221.2 (-3.8 lbs) Attitude - still trying to find that sweet spot where I balance capability with weight loss. At this point, I'm not limiting fruit intake (fructose) at all, I drink milk (lactose), still eat chocolate but that still wasn't enough glucose fuel for me. So I had to start adding truly starchy items like breads or potatoes and I think that for me, having 2 starchy items a day allows for weight loss but my metnal cupasity ain't quite firing on all cylinders yet. I'm going to allow for three servings on days I exercise. Biochemical lesson - Ketosis, finally. I pause to admit it, but the whole way one's body fits this together is actually kinda cool. Our body cobbles together our metabolism out of bits and pieces. To me, it is NOT some highly tuned fine machine. It's some organism that has managed to keep afloat despite itself. I think that it all starts with the brain (and red blood cells). The brain requires glucose. Why, I don't know. From what I can tell, fatty acids can cross the blood/brain barrier. Red blood cells (RBC) require glucose because they have no organelles, ie they have no mitochondria (the little factories) in which to burn fats. So they must utilize glucose. Why they don't have organelles? I suspect it's because RBCs are essentially there to transport oxygen and that's it. After about 4 months, they breakdown and die. They really don't need any DNA or organelles to do that job so it must give some advantage to not waste the materials on them. Kinda analagous to replacing some factory workers with a robot. A brain is not really required to perform the task. So back to ketosis. Those two NEED glucose. Well, let's take an ancient ancestor of ours named Mog. Let's say he can't kill anything for a few days and has yet to find any good fruits around. The brain has to keep going and the RBCs have to keep carrying oxygen or he's going to run into a world of hurt when trying to avoid a predator. The body has cobbled together a clever solution to deal with it. It needs glucose so why not make it? For that to happen, two main elements are required. #1 - a carbon skeleton to build a glucose molecule (think of it like a frame on a car) and #2 - the energy to drive the process. Our body uses fats to drive the energy and protein to use as the carbon framework. It seems strange to consume energy to make energy but we do that all the time. Think gasoline. It takes energy to find, extract crude oil and refine it into useable gas. The net result is that we get more energy from that process. That's one of the complaints about corn based ethanol - it consumes as much, if not more, energy than it provides. Our bodies, are like the corn scenario, not the crude oil. We burn calories (in this case fat) in order to build glucose. It's a net caloric loss which is one of the reasons that weight comes off so quickly with these low carb diets. Like I said, not the best of designed systems but it works. But your body can only burn so much fat for 2 important reasons. First, fat breaks down into a compound called Acetyl CoA. It then goes into a process that everybody saw in high school biology called the Krebs Cycle (or TCA cycle for tricarboxylic acid cycle). It's a cycle so the beginning is the end. The CoA is liberated and recycled to join up with more fat and keeps going. Two problems occur when Mog is cruising through fat to make glucose. He pulls intermediates out of the Kreb cycle to synthesize glucose whole cloth. It's a cycle. If he keeps pulling things out, it doesn't cycle anymore. So it slows down which means less glucose and less energy. Enter the second problem. There's only so much CoA your body has. It's a finite pool and when Mog hasn't eaten, it's all tied up in breaking down fats (in financial terms, it's not a liquid asset at the moment). So he has to free up some of that CoA. Enter Ketosis, your body's last resort at keeping things moving. He changes Acetyl CoA into molecules called Ketone Bodies. Those can exported from the liver and used in the muscle as a source of energy (the brain eventually will use them after prolonged periods, something like 6 weeks). So Mog's liver has saved the day. He has provided the muscle with an alternative source of energy while still allowing for the synthesis of glucose. It's an energy wasting process in the long run which makes it a useful tool for losing weight in the short term. Long term weight loss with any means is a different story.