Carbohydrates are one of the three macronutrients we need to survive (the other two being fats and protein). Weight gain occurs when the amount of energy we eat is more than the energy we expend1. Therefore, eliminating an entire food group will result in weight loss because it is difficult to meet your nutritional and energy requirements with the remaining two food groups. However, carbohydrates do not inherently cause weight gain in isolation2.
Why do we need to eat carbs?
Carbohydrates are broken down into glucose, which is the body’s preferred source of fuel. Glucose is needed to provide energy for every process in the body. Additionally, glucose is able to cross the blood brain barrier, which means it can power the brain (fats and proteins cannot, unless broken down further into ketones, which is inefficient). Furthermore, carbohydrates are our primary source of fibre, found in fruits, vegetables, wholegrains and legumes (all sources of carbs), which is important to keep the bowel healthy.
Quality counts!
Not all carbohydrates were created equal. If you are consuming most of your carbohydrates from highly processed sources, such as lollies, cakes, biscuits, pastries and chips, then you are likely not getting the greatest bang for your buck! There is a large body of research that consistently demonstrates that people who eat most of their carbohydrate from wholegrain sources, such as wholegrain bread, pasta, brown rice, as well as legumes and fruits and vegetables, experience a lower incidence of chronic disease such as Type 2 Diabetes, cardiovascular diseases and certain cancers3. Therefore, brandishing all carbohydrates as weight gain inducing is inaccurate and potentially harmful.
Is it dangerous to cut out an entire food group?
It can be! By eliminating an entire food group, it is very difficult to meet your nutritional requirements, which can lead to malnutrition. Also, if you eliminate carbohydrates and are consistently under-eating, then your risk of developing the refeeding syndrome can increase. The refeeding syndrome is a dangerous collection of symptoms and a cascade of events that can lead to death when carbohydrates are reintroduced to the diet following a period of undernutrition4. Electrolyte derangement and subsequent heart complications occur, which can cause cardiac arrest4.
Additionally, by eliminating carbohydrates from your diet, you are risking a low fibre intake, which carries a swathe of potential complications. Particularly, it is well established that a low fibre intake can increase bowel and colon cancer risk5. Fibre also plays a role in cardiovascular health, helping to keep blood cholesterol levels within normal parameters3.
As you can see, choosing to eliminate an entire food group must be considered with nuance and a critical lens. There are specific situations in which carbohydrate reduction or elimination may be appropriate, but must be discussed with a dietitian and medical professional. It is really important when considering any dietary change that you consult with a dietitian to ensure you are well-informed and supported in your journey. To book a consultation with Carly, our dietitian, please contact the practice on 9439 6776.
References
1. Energy Balance and Obesity, Healthy Weight Basics, NHLBI, NIH [Internet]. Nhlbi.nih.gov. 2020 [cited 25 September 2020]. Available from: https://www.nhlbi.nih.gov/health/educational/wecan/healthy-weight-basics/balance.htm
2. The truth about carbs [Internet]. nhs.uk. 2020 [cited 25 September 2020]. Available from: https://www.nhs.uk/live-well/healthy-weight/why-we-need-to-eat-carbs/
3. Aune D, Keum N, Giovannucci E, Fadnes L, Boffetta P, Greenwood D et al. Whole grain consumption and risk of cardiovascular disease, cancer, and all cause and cause specific mortality: systematic review and dose-response meta-analysis of prospective studies. BMJ. 2016;353(i2716).
4. Mehanna H, Moledina J, Travis J. Refeeding syndrome: what it is, and how to prevent and treat it. BMJ. 2008;336(7659):1495-1498.
5. Gianfredi V, Salvatori T, Villarini M, Moretti M, Nucci D, Realdon S. Is dietary fibre truly protective against colon cancer? A systematic review and meta-analysis. International Journal of Food Sciences and Nutrition. 2018;69(8):904-915.
6. Threapleton D, Greenwood D, Evans C, Cleghorn C, Nykjaer C, Woodhead C et al. Dietary fibre intake and risk of cardiovascular disease: systematic review and meta-analysis. BMJ. 2013;347(dec19 2):f6879-f6879.