I often talk to my clients about developing "metabolic flexibility", the ability to burn both carbohydrates and fats for efficient energy in the body. With our current "normal" eating patterns, we are so heavily based in carbohydrates (sugars and starches) that our bodies never are stimulated to create the metabolic pathways to burn fatty acids, so we become almost exclusively carb-burning machines.
Think of it like a hybrid car. A Prius... The car is designed and engineered to use electricity for many functions, including propelling the car forwards at lower speeds. It is a completely clean, no waste-creating, efficient system. The car also has all the systems in place for burning gasoline, and this system kicks in when the "environmental signals" are right - higher speeds, faster acceleration required by pressing harder on the gas pedal. Works great to create energy, but it's a fuel that burns dirty, creating byproducts (exhaust) that require another whole system to deal with and dispose of.
The car determines which fuel to burn based on signals from its environment - meaning the driver's requests of the car. The driver is like our brains - assessing the requirements of the situation and signalling to the car (by pressing on the gas pedal or brake, changing gears, etc) what response is required. The car itself either utilized its electric system or the gas system - the driver doesn't choose. That is hardwired into the car.
If one or other of the fuel systems was deactivated in your Prius, the car would not work properly. Your ability to smoothly go places, accelerate when needed, send signals out (turn signals, etc) would be severely limited. You may still be able to move the car, using only one system, but it wouldn't be a smooth or efficient ride...
Likewise, we are evolved with the ability to burn several different fuels in our bodies. However, not all of the systems are operational in most of us, because we never give our bodies the chance to rev up our fat burning pathways. In fact, by feeding ourselves carbohydrates every couple of hours throughout the day (and sometimes the night, too!), we have signalled to our body to shut down the fat burning metabolic pathways, and they simply are "down-regulated", disassembled and mothballed. The genetic blueprint for them is still there, but we haven't bothered to build them, because the "environment" in our body is totally focussed on carbs. Our hormonal signalling system senses only carbs coming down the pipe, so our blood insulin levels remain high to deal with that, and the really efficient metabolic pathway - the cleaner burning, more fuel efficient fat burning mechanism - never gets a chance to kick in.
By changing the "environmental signals" using a low carb, high healthy fats diet, we can signal our bodies to re-establish the fat-burning mechanism and kick it into gear. This clean burning fuel source is endless, as we all carry hundreds of thousands of calories of energy in our body fat stores. Once the fat-burning engine has been reinstalled, we are never caught seriously short of fuel again, unlike the situation that can happen with carb dependency - low blood sugars, brain fog, "hangry" irritability (that's the slang for "angry-hungry" that carb dependent people will recognize when they need to eat - like NOW!).
The cool thing is that once that new machinery is installed, it's yours for good. If you are clicking along, feeling great on a low carb diet, then you eat a crapload of sugar or starch for some reason, you will likely feel "crappy" for a few hours while your body deals with the carbohydrate energy burning, but the next day, you wake up again, back to your normal fat-burning state.
This happened to me this past weekend - a very "smack-me-up-the-side-of-the-head" example of this. I had to run straight from church to the local theatre for rehearsal of the big fall musical, in which I am a Wardrobe Lead. Despite having a solid breakfast (early because of the time change...), I was hungry when I arrived at the theatre about 12:15, and there was nothing to eat but sugar treats and little Halloween-sized bags of Doritos. I admit that I fell face first into a home-made treat called Scottish Tablet - basically a brown sugar/butter/sweetened condensed milk confection - all my favourite flavours together in one food. Not a scrap of protein or fatty foods in the place - only sugars. And I hadn't thought to bring something better - my bad. Well, rehearsal ran until almost 6 p.m., fueled by sugar and Doritos. I could feel the sugar rush, the slightly headachy feeling that follows it, the fatigue, and I missed a major cue for getting one of my actors into a quick change. I felt awful...
When I got home, I nuked a bowl of leftover beef stew and basically wolfed it down, followed by two large cups of tea to rehydrate (another problem from the afternoon). Felt somewhat better almost immediately, but still off...
The cool thing is that the next morning, I was able to get up feeling my usual fineness, and get right back on the wagon with delayed breakfast (Eat W.H.E.N. - when hunger ensues naturally), and ate low carb without any problem all day. The underlying machinery for fat-burning was still there, and was reactivated as soon as I gave it a break from the sugar deluge. That's metabolic flexibility. I can eat the crap - dirty burning, short acting fuel - but the machinery for efficient, clean burning fat metabolism is now installed in my body and ready to serve me well. It's a great feeling...
Share on Facebook
Share on Twitter
I'm busy working on my blog posts. Watch this space!