Today’s lesson looks at the fuel your body uses in both physical activity and every day life: fat or carbs (sugar). Until I started reading about low-carb, high-fat eating, these terms weren’t even on my radar. That said, until I started reading about primal eating, I thought I knew a lot about ‘healthy eating;’ it turns out I knew nothing. And that was why I was gaining weight.
Disclaimer: I’m not a registered dietician, I’m just someone who has done their research and successfully implemented a primal way of eating, and has seen major benefits. I do, however, plan to certify in the next year.
Your body can use one of two fuels: fat or carbohydrates (sugar). What each entails and feels like is totally different though, let me explain.
Carbohydrates = Cheap fuel
Those who are not in the primal know say that carbs are the body’s preferred source of fuel; this is a very misleading statement for many reasons. The most important is because the body doesn’t actually prefer carbs as fuel, it needs to address what carbs do to our physiology, which is misinterpreted as our body fuelling up. It’s basically the science behind primal eating: carbs, unlike protein and fat, raise our blood glucose (sugar) levels. This is toxic to our bodies, so we release insulin to lower it. To you, this would feel like the high you experience after eating a carb-laden meal and/or sugary food. Then you crash – this is your blood glucose levels falling too low. So your body says you need to feel good again, communicating this as hunger signals. You eat, you feel better for a bit, then you crash, feel hungry, eat, feel better for a bit…. etc.. This act of experiencing constant high’s and low’s is stressful to your body. In response, it releases cortisol – your stress hormone – which sends your body into fight or flight survival mode. Your body is desperate for sugar, but there is none, so it eats your muscle for fuel instead.
Yes, your body just ate your muscle for fuel. Your body ate itself because it was so stressed. Reminds me of the Bonies in Warm Bodies, who ate their own flesh. Your body can use muscle for fuel through gluconeogenesis – a process by which the body can obtain glucose and glycogen (energy stored in the liver and muscles) from substances which aren’t carbohydrates. The word actually means ‘create new sugar.’ This muscle-eating can also occur when you feel hungry but don’t/can’t eat, and you actually start to feel famished. Then, for some reason, the hunger eventually goes away. Why? It just cannibalised itself again. Gluconeogenesis can also occur with protein in our body, minus the muscle-eating bit.
While carbs can be used as fuel – and for too many are used as fuel – it’s actually seen as a cheap fuel because our body converts it to glucose (sugar) and it burns incredibly quickly. The body can only store about 2000 calories of carbs, which looks like 350-500 grams of stored glucose in our muscles as glycogen (muscle energy); this is enough to say, run 90 minutes. Your liver also produces glycogen, about 100g. Any longer distance runner (or athlete) knows that to keep going without hitting the wall – running out of glycogen– you need to refuel often using quick-acting, quick-burning gels, bars or gummies. If you don’t, you hit the wall, crash, bonk. This looks like the people that are staggering, crawling, to the finish line of a marathon, an Ironman, even a half marathon with inadequate fuelling, because their fuel stores are done. And when this happens, again the body is eating muscle as a last ditch attempt for fuel.
Carbs are quick energy, but not lasting. They’re cheap. They make you eat your muscle if you don’t fuel again in time. They run out very quickly. They’re not actually essential to our survival. Our body can make glucose (and glycogen) on its own without our needing to consume it. Our brains and muscles need some glucose and glycogen to function – how much depends on whether you’re a sugar-burner or fat-burner – but they don’t need nearly as much as we think they do, and how much mainstream health tells us we do. If you’re an athlete that trains longer and multiple times a week, you will have to eat a bit of energy through tubers, but again, not to the amount that we think we need to.
Eating a diet that consists of a lot of carbs through grain consumption, sugar consumption, high fruit intake, and processed foods, make you a sugar-burner. How do you know through and through that you’re an SB? By these telling signs:
- You get cravings, and get them often
- You are hungry all the time
- You can’t go more than three hours without eating.
- And as a result, you eat 5-6 times+ a day.
- You sometimes (all the time?) feel like you just can’t stop eating.
- You need to eat before you workout or else it’ll go badly.
- You experience the late afternoon blahs, where you’re tired and it feels like your brain no longer works.
- You experience brain fog, meaning this feeling of your brain not working.
- You experience the high’s and low’s I referred to above.
- Your hunger is an all-consuming monster. You need to feed it and you need to feed it now!!!!! You can’t do anything until it’s fed, And if you don’t, watch out because…
- You get hangry. Hunger + angry is not a nice thing to be around. I’ve seen it.
- You can experience hunger in the middle of the night and feel the need to eat.
- When you’re really hungry, you feel faint.
- Your diet is akin to the UK’s Eatwell Plate, the Canada Food Guide, the USDA MyyPlate/MyPyramid, or the Australian Healthy Living Pyramid (four examples in the western world). Or your countries version of low-fat, high-carb eating.
I used to feel all of the above, all the time. Is this you? I don’t know about you, but once I read all the information on carbs and how they give you energy, I couldn’t help but think that this wasn’t a good source to depend on. Plus, over-consumption over time leads to several serious health implications… Type 2 Diabetes for one.
You know what is a rich source of energy? Fat.
When we were early humans, our bodies were actually adapted at burning fat for energy, it was their preferred energy source. This allowed them to survive when food wasn’t so plentiful, fasting if need be.
Fat doesn’t affect our metabolism the way carbs do; it doesn’t touch our blood glucose levels, which allows us to feel stable all day long, rather than experience high’s and low’s. If you’ll remember from the science of primal eating, our fat cells are open for business, allowing fatty acids to travel around and feed our cells; this explains why we aren’t perpetually hungry all day long. We can continue this uninterrupted cycle with a primal diet (low-carb, high-fat); it’s only when we consume grains, legumes, sugars, ample fruit – which all raise our blood glucose levels – that this fatty-acid-eating cycle is disrupted. And if you’re a sugar-burner, this happens often. In a sugar-burner, our fat cells would shut for business whenever our blood glucose levels increased due to high carb consumption, then open again once blood glucose levels are back to normal (1 teaspoon). To make a long story short, if this cycle were to continue, one would continue to gain weight, and would also become leptin-resistant, insulin-resistant, and fall under many, if not all markers for Metabolic Syndrome.
Our brains are made of mostly fat, so it makes perfect sense to use a familiar fuel. Our muscles burn fat as fuel more efficiently and without needing so much glycogen, so things like getting heavy legs, ‘hitting the wall’ and feeling the need to fuel up pre-exercise are non-existent, or at least prolonged, (you’d still hit the wall if you ran a marathon or did an Ironman). We can store up to 100,000 grams (close to a million calories!) worth of fat; pretty heft compared to carb storage. And we don’t have to fat-load to accomplish this. And you’ll never get into desperate muscle-eating territory.
The only downside to being a fat-burner is that you can’t train hard and long all the time, but you can effectively burn fat when training in the fat-burning zone. If you were to train hard and long all the time, this is where supplementing with tubers to supply your muscles with additional glycogen comes in to play. For me, this only happens leading up to a run of 9+ miles or a race. I run long and hard about once a week, and my fitness is the best it’s ever been.
Being a fat-burner means that you are using fatty acids in your fat stores, or fat from your diet, as energy. And once you become a fat-burner, it will feel like night and day! Here’s how to know you’re definitely a fat-burner:
- You have energy all. Day. Long. I’m not talking about the buzz you feel after drinking a sugar-laden drink or espresso; the lasting energy that you feel you could just keep going all day long.
- You feel great. You really do.
- You have mental clarity all. Day. Long, even in the late afternoon at work.
- Hunger doesn’t rear its ugly head. In fact, your hunger pangs are tiny in comparison to the hunger monster you used to have to deal with.
- No cravings!
- No hanger!
- You eat about every 5-6 hours, but can go longer if need be. And you won’t feel famished if you do.
- You eat 2-3 meals a day.
- You can exercise in a fasted state.
- You don’t need a pre-exercise snack, meal.
- You can engage in the occasional fast and function normally.
- At times, you forget to eat because you’re so used to relying on hunger to tell you when it’s meal time. Then you look at the time and realise “I haven’t eaten in 8 hours!” And you still feel great.
And we can effectively burn fat, from our diet or our stores, once we become a fat burner. How do you become a fat-burner you ask? By eating primally and making sure you get a lot of fat, every day, (and don’t even think about fat-burning pills!). Eat fat to lose fat! Yes, sugar-burning primal/paleo eaters do exist. Your aim is to not to be one.
Are you a fat burner or a sugar burner?