…That is indeed the question! Carbs. Once an unremarkable nutritional compound, it seems carbohydrates – now lovingly known as “carbs” – have become a household name. But why are we so obsessed with them? What are they? Should we be eating them? Are they the source of all our modern lifestyle diseases or simply a nutritious part of a balanced diet? The views in both the public and the nutrition profession are wide and varied, and very conflicting, so it’s not surprising that a lot of people are very confused about carbs.
Hopefully I can dispel at least some of that confusion for you today, and help you to make your own informed decision about the role carbohydrates play in your diet.
What Are Carbs?
Basically speaking, our human diets are made up of three “macro” nutrients – carbohydrates, proteins and fats. From these three main groups our bodies get the majority of the building blocks they need to build, repair and function. Carbohydrates are compounds made up of sugars – They come either as straight simple sugars (e.g. glucose, fructose), disaccharides (e.g. sucrose – table sugar; lactose – milk sugar) or complex carbohydrates (e.g. starch, cellulose).
Where do they come from? All plant-based food sources contain carbohydrates – they are the energy source that plants make through photosynthesis. Fibre is also a form of carbohydrate. The lactose found in mammalian milk is synthesised from two simple sugars – glucose and galactose; the presence of lactose in mammalian milk means dairy products are also a source of carbohydrates. Additionally, any food product made from plants (e.g. pasta, fruit juice, hummus) and any product that has any form of sugar added to it (soft drink, sweets, commercial pasta sauces, most manufactured foods) becomes a dietary carbohydrate source.
What do they do? Carbohydrates form the main source of ENERGY for our bodies. This doesn’t just mean energy for your daily cross-fit session – we’re also talking about cellular energy, the energy needed for every cell in your body to continue to function and contribute to your overall health. Of particular interest here is your brain – you may have heard that your brain needs carbs. This is an over-simplification – our brains need glucose, but our bodies can manufacture glucose from other energy sources (most importantly, fat). When your blood sugar levels have dropped too low and you start experiencing the familiar symptoms such as brain fog, crankiness and general “hanger”, a simple carbohydrate source is what you crave. Why? Because that’s the quickest and easiest way to get that glucose level back up and feed your brain again.
Do we need carbs?
So, if our bodies can use fat (and protein) to produce energy, why do they need carbohydrates? Let me offer two answers for you to consider:
- Carbohydrates offer the body the quickest and most efficient way to make energy. The metabolic pathway that produces cellular energy (do you remember ATP from high school biology?) most efficiently is the Krebs Cycle (citric acid cycle), which uses glucose as an input and produces ATP at the other end. Fat and protein can also be converted to ATP but it takes a lot more work – the energy input is much higher, which means the body has to work harder and use energy reserves to create more energy, so the return on investment is much lower. This is great if you want to lose weight, not so great if you’re about to pass out from low blood sugar!
- We eat food, not macronutrients. This is a big one to remember. When we eat something we think of as “carbs”, whether that be a slice of sourdough, a piece of fruit, a bowl of pasta, or a nice lentil curry, we aren’t just getting sugar and calories. We’re also getting essential minerals, fatty acids, B vitamins, fat soluble vitamins, anti-oxidants, phytonutrients, soluble & insoluble fibre. All these nutrients tend to work synergistically in our bodies, providing all the moving parts necessary for our bodies to metabolise the specific foods we’re eating. Here’s an example: when you eat a grain – a whole, unprocessed, not too genetically-messed-with grain, grown in not-too-depleted soils (so yes, a fairytale grain!!) – your body gets carbohydrates, sure. But it also gets: zinc, B vitamins, selenium, magnesium, chromium, iron, manganese, soluble and insoluble fibre, and Vitamin E. Guess what nutrients your body needs to metabolise carbohydrates? B vitamins, zinc, magnesium, copper, & iron; the chromium helps shuttle glucose from the blood into the cells, basically assisting insulin function; and the zinc, vitamin E and manganese help protect against oxidation caused by some of the byproducts of the process*. So along with your carbohydrates, you’re also getting the minerals and other nutrients needed to metabolise the carbohydrates and to minimise the effect on your blood sugar and help your body use the energy efficiently. (*this is an oversimplification, but we’re not in a nutritional biochemistry lecture here so it will suffice!)
So.. Are we eating too many carbs? As we know, the human body can make glucose out of other dietary components – this is an adaptive mechanism to protect against starvation in times of low nutrient intake. Our bodies are really clever like that. From an evolutionary perspective, our ancient ancestors lived in an environment that was not replete with rich carbohydrate sources. As a result, our bodies are well adapted to function on small amounts of carbohydrates, and to be able to store and convert fat and protein into glucose when needed. But carbohydrates are still the preferred energy source for humans – this is why the sweet taste is perceived as enjoyable and desirable.
We are primed to seek out sweet foods because they provide the most nutrient density (ignoring our current food supply for the moment) and therefore the most energy for the least amount of effort, even though that energy is short-lived. Hunting and killing and butchering a large animal for protein and fat takes a lot more energy, but our bodies can store that energy for much longer. Jump forward to our modern food system: We now have access to a huge, unending supply of carbohydrate-rich foods, most of which have been refined and processed in a way that strips them of other beneficial nutrients. This leaves us with a situation where we still have that instinctual attraction to sweet foods, but there is never any shortage, and we don’t use that energy for hunting down our protein & fat sources – these too are in plentiful supply.
The result: yes, most of us are eating more (sometimes, a lot more) carbohydrates than we need to.
What’s the problem with this? Firstly – my main concern is that if you’re eating lots of foods that are high in carbohydrates, what other foods are they pushing out of your diet? Let’s take an extreme case that is probably less extreme than I’d like to think. Let’s say you have cereal for breakfast, a ham and cheese sandwich for lunch, and pasta carbonara for dinner. You’ve had heaps of carbs, hardly any vegetables (potentially none at all), and very little good quality protein and fat. You might be very full and satisfied, not overeat, and rarely eat things such as chocolate, cakes or desserts, but you’re still getting very few beneficial nutrients, and your body is using a lot of minerals and vitamins to metabolise all those carbohydrates.
Secondly – there’s no getting around the fact that diets high in sugars are linked to many, if not all, of our current chronic disease burden. The increased inflammation, decreased digestive health, insulin dysregulation, hormone disruption and micronutrient deficiencies commonly caused by high sugar diets are unavoidable facts that show we would, as a population, benefit from reducing our intake of sugar and carbohydrates.
What’s the alternative? Firstly – avoid extremes! There’s no need to completely cut out carbs – indeed that would be pretty difficult unless all you ate was muscle meats and fat, and you’d rack up some nutritional deficiencies pretty quickly doing that.
Secondly – rethink the way you approach your meals. We talked about the key macronutrient groups earlier; if you build each meal and snack around these macronutrients, you’ll be much less likely to over-consume carbohydrates & sugars. To further refine this idea, I encourage people to build their meals on vegetables, protein and fat. By doing this, you’ll find it much easier to get heaps of great nutritious foods into your body at each meal, and likely feel more satiated and less likely to have energy slumps and sugar cravings. Don’t feel like you can’t add bread, pasta, rice etc into these meals – just move away from using these as the basis for your meal, rather as a side-dish or small component.
Third – choose more nutritious carbohydrate foods. When you’re eating grains, go for those that have been minimally processed. If you love a sweet treat, make it yourself from ingredients you are happy putting into your body and in quantities you are comfortable with. Consider non-grain alternatives that are higher in protein, fat and essential nutrients and lower in carbohydrates (e.g. amaranth, millet, quinoa).
Fourth – when you’re hungry, eat! Don’t let yourself get too hungry, this is when the sugar-beast will kick in, and you won’t be satisfied until you’ve eaten something that gives you a quick blood sugar hit. Eat protein and fat at each meal, eat as regularly as you need to, listen to your body. Appreciate the fact that your appetite will fluctuate on a seasonal, monthly and even daily basis, and with your age, activity levels, general health (and many other factors).
Other hints and tips:
- When eating food that is a rich source of carbohydrates (grains, root vegetables, sweet foods) always add some protein and fat. Why? because (a) it will make you feel fuller more quickly so you won’t be as likely to over-eat; (b) you’ll lower the overall glycemic load of the meal, making your blood sugar reaction more stable; and (c) you’ll be adding some more beneficial nutritious foods to your diet without really trying
- for example – love a croissant every now and then, or a hot cross bun at Easter? Make sure you buy baked goods made with butter, not margarine or other vegetable or seed oils, and enjoy them with some grass-fed butter to slow down absorption of carbohydrates.
- love your dried fruit? eat it with a handful of nuts and seeds, or try it with some natural yoghurt
- craving a baked potato? top it with some ground beef and yoghurt, or tuna and grated cheese, or kidney beans and fresh coriander.
- Rather than worrying about carbs in general, just focus on added sugars in your diet. If you can minimise the amount of added sugar – rather than naturally occurring sugar – in your daily food intake, you’ll be well on your way to eating a nutritious diet.
- Eat more veggies 🙂 You knew I was going to say that. It’s seriously the best way to get heaps of great nutritious energy-rich food into your diet, and reduce your reliance on grains and grain products. Eat locally grown, choose lots of variety and bright colours, and your body will thank you for it.
Well, that sure got long!! Hopefully I’ve answered some of your more pressing questions and helped you decide how to include delicious carbohydrates in your diet – please don’t hesitate to ask if you’ve got more questions. As always feel free to contact me directly or via my Facebook page if you’d like more information.