Carbs have been vilified a lot in recent years, with some of the latest diet trends advocating ‘carb avoidance’. This goes against most people’s normal eating pattern and much of the dietary advice given by qualified healthcare professionals and governing bodies. So, if low carb diets are so successful and cutting out carbs helps with weight loss and disease risk, why is it that the messages being given out by healthcare professionals isn’t catching up with the proven success stories seen daily in the media?
Part of the problem may be a tendancy to ‘lump’ all carbs together in one category, but just as we’ve heard a lot recently about not all fats being equal, neither are carbs…
What are carbs?
Simple Carbs- or for those of us to like to keep it simple, sugars! These are the smallest molecules of carbs and are found naturally in foods, like fruit, honey and milk, and are often added to processed foods (usually in high amounts). Most of us know to avoid, or at least limit, the sugars that are easy to spot, like in sweets or sugary drinks like colas. The issue can become a little more complicated when trying to spot added sugars in shop bought processed foods, for example savoury sauces.
Complex carbs- or starches, are long chains of sugars and can be found in foods like potatoes, rice, pasta, bread and cereals. Some complex carbs are high in fibre which has proven health benefits for our digestive system, additionally fibre promotes healthy gut bacteria which have recently been linked to many health benefits outside the gut such as type 2 diabetes, heart health and metabolism.
Studies recently have indicated that advice to replace fat in the diet with some carbs can contribute to weight gain, type 2 diabetes and heart disease(1). This had led to a bit of a face off between our 2 major energy providers, but a black and white view of fat vs carbs in the diet may be unfortunately oversimplifying the matter. The fact is that some carbs are protective against disease and weight gain, as are some fats(2,3). As with all other dietary matters, it’s a case for careful consideration rather than generalisation.
Depending on which diet you choose, the extent to which it is actually low carb can vary wildly. It is actually fairly hard to exclude carbs altogether as they are found in such a wide variety of foods. Some of the more strict low carb diets advocate very little fruit and even restricting or banning certain vegetables and pulses, which not only means cutting out the carbs but also cutting out all the other nutrients they provide. This could prove quite detrimental to long term health unless you are very careful to ensure you are getting these nutrients elsewhere in your diet. Any low carb plan that also recommends supplemental vitamins or fibre is demonstrating that the diet isn’t nutritionally complete so bear this in mind when considering whether to try it. Don’t forget, very restrictive diets may also be difficult to stick to in the long term, consider what will happen to any benefits you have gained, if you were to give up.
So what’s the bottom line? As not all carbs are equal, common sense would suggest that careful consideration of which carbs we include is something that we should be considering. My suggestion would be to start with cutting out (or reducing as far as possible) those that provide empty calories such as the added sugars found in processed foods, sugary drinks cakes and sweets but continuing to include those with health benefits like fruit, vegetables and wholegrains. If after restricting these, you have not achieved your dietary goal, perhaps consider looking at portion sizes of the carbs you are still eating before going to the more extreme tactic of cutting out carbs altogether.
Di Nicolantionio JJ. (2014) The cardiometabolic consequences of replacing saturated fats with carbohydrates or W-6 polyunsaturated fats: Do the dietary guidelines have it wrong? Open Heart 1:e000032.doi:10.1136/openhrt- 2013-000032
Aune D, Keum NN, Giovanucci E, Fadnes LT, Boffetta P, Greenwood DC, Tonstad S, Vatten LJ, Riboli ER, Norat T. (2016) Wholegrain consumption and risk of cardiovascular disease, cancer and all cause specific mortality: systematic review and dose-response meta-analysis of protective studies. BMJ; 353: I2716
Yanping L, Hruby A, Bernstein AM, Ley SH, Wang DD, Chiuve SE, Sampson L, Rexrode KM, Rimm EB, Willett WC and Hu FB. (2015) Saturated fats compared with unsaturated fats and sources of carbohydrates in relation to risk of coronary heart disease: A prospective cohort study. JACC; 66 (14), 1538-1548