Carbohydrates are a large group in the food pyramid. For this reason, it is important we understand them. Amongst body conscious populations, carbohydrates are seen as a guilty indulgence. I believe carbohydrates are largely misunderstood and we need to educate ourselves on enjoying pasta, rice and bread in the healthiest ways possible.
Carbohydrates have a pretty bad reputation. They are too often blamed for the current obesity crisis, as well as the increasing prevalence of type 2 diabetes. This is only a half truth. Highly processed carbohydrate products such as white bread and cakes, confer high blood glucose (sugar) spikes that contribute to obesity and diabetes. These products are responsible for the negative connotation surrounding carbohydrates, and should be limited.
On the other hand, whole grain products such as brown rice and whole meal pasta help combat obesity and diabetes. The primary difference between whole grain and ‘white’ carbohydrate products, is that whole grains contain the germ and bran of the grain, as well as the starchy endosperm that constitutes ‘white’ grain. The germ and bran are rich in dietary fibre, minerals, healthy fatty acids, phytostreols, phytochemicals and other healthful compounds. Furthermore, bran increases resistant starch within the endosperm, acting as a barrier to digestion.
Due to increased dietary fibre and resistant starch within whole grains, their consumption offers less dramatic blood glucose spikes. Low blood glucose spikes put less pressure on the pancreases and are protective against type 2 diabetes. Dietary fibre and resistant starch slowly release glucose to the body. This prolongs satiety (the sensation of being full), prevents over eating and decreases the risk of obesity. Dietary fibre and resistant starch travel through the majority of the gastrointestinal tract undigested and end up at the large intestine, intact. Here, gut bacteria, known as microbiome, ferment carbohydrates, producing a variety of healthful compound such as short chain fatty acids (butyrate), B12, folate, biotin and methane gas. These compounds are responsible for anti-cancer and anti-inflammatory responses in the body (especially butyrate). By consuming a diet high in fibre and resistant starch, the growth of ‘good’ bacteria bacteria (Prevotella) is favoured, contributing to a microbiome that offers a symbiotic relationship with the body. High fat and protein diets, are associated with the feeding and propagation of ‘bad’ bacteria (Bacteriodies) which are not nearly as beneficial to health. I know brown rice isn’t as fluffy and nice as white, but surely the health benefits are worth a small sensory consequence.
Not all whole grains are equally as healthy as each other. For this reason, consumers need be critical of the products they purchase. The governing body for food labelling, FSANZ, defines ‘whole grain products’ as any food that incorporates every part of the grain inclusive of the bran and germ. This includes products where the bran and germ are separated from the white endosperm during processing, ground to flour and then re-packaged together. By separating the bran and germ from the endosperm, resistant starch is markedly decreased. Furthermore, when grains are intact, enzymes that breakdown healthful compound are kept in isolated cells. By grinding the gain, cell contents are mixed and enzymes are free to breakdown the healthful compounds our body desires. Consumers prefer their whole grains ground separately, which is why such products are abundant on the supermarket shelf. However, you body prefers them intact. So, when selecting your next loaf of bread, buy the crunchiest, chunkiest loaf you can find.
The main function of carbohydrates is energy metabolism. Excess carbohydrates are stored as glycogen in the muscle and liver. This is the theory behind carbohydrate loading before endurance exercise – it increases fuel stores prior to a race. Only if carbohydrates are consumed in abundance, are they incorporated to fat. On the opposite end of the scale, an extremely low carbohydrate diet can contribute to fat production. When too few carbohydrates are consumed, carbohydrate becomes a limiting factor in energy metabolism. This results in a build up of Acetyl Co-Enzyme A. The build up is then diverted down a lipogenesis pathway, resulting in fat production. Extreme low carbohydrate diets (for example Atkins) are therefore not as ‘slimming’ as they claim.
The food pyramid recommends incorporating carbohydrates to the daily diet, and this is something I fully endorse (so long they are of the brown, whole grain variety). Learn to love wholemeal pasta, bread and brown rice so that your body (and the the bacteria residing in your gut) will love you back, and reward you with a long healthy life, free of type 2 diabetes.
Renae Earle is a Masters of Dietetics student at the University of Queensland. Having achieved her Bachelor of Exercise and Nutrition Science with distinction, she is motivated to complete her studies and become an accredited practicing dietitian.
Renae is passionate about evidence-based practice and debunking nutrition myths. She believes that in today’s fad celebrity diet culture, it is increasingly important to deliver the facts. She aims to help people achieve a sustainable and healthful lifestyle by combating the flurry of misinformation offered by tabloids and social media.
In order to achieve this goal, Renae has dedicated herself to the field of nutrition. She is well educated on a wide range of nutrition topics such as supplementation, chronic disease, restrictive diets and metabolism.
Renae has a keen interest in offering personalised nutrition plans that suit the specific needs of her future clients.