Considering going Paleo? Thinking of trying keto? Pondering a low-carb high-fat diet? You might want to read this first.
Nutrition science is almost always more nuanced than the soundbites presented in mainstream media. With the rise of social media, we are constantly bombarded with the latest food fads, foods to eliminate, or "superfoods" we simply must work into our daily lives. As always, the devil is in the details.
When an association between saturated fat intake and cardiovascular disease was discovered in the 1950s, food manufacturers responded by developing an enormous range of low-fat foods to meet the resulting consumer demand. The idea that "all fat was bad" prevailed, but it meant that people were eating highly-processed, low-fat foods that were often higher in sugar and total energy (kilocalories or kilojoules) than the original product, just to avoid any and all fat.
Now it seems carbs are in the firing line. Unfortunately, the message is often over-simplified so that it would seem all carbs should be avoided, rather than just reducing your consumption of the less healthy options. Carbohydrates are our body's preferred source of fuel. Carbs provide most of the energy our bodies require to do all the things we need to do, as well as all the things we want to do. It's the fuel our brain depends on, although it can run on an alternate fuel if it really has to, such is the importance of a working brain!
Talking to fellow nutritionists, I have discovered we have all met with clients who have been genuinely afraid of carbs. The feeling is that carbs should be avoided at all costs as they will lead to weight gain, such is the prevalence of the anti-carb message. Often these clients are experiencing fatigue (due to carbohydrate restriction), and gastrointestinal issues (due to a low-fibre diet). In addition, a dietary pattern devoid of a variety of wholegrain carbohydrates often means these clients struggle to feel full without these valuable foods, which can lead to difficulty managing weight.
Regularly consuming high-fibre and whole grain foods is associated with a reduction in the risk of developing cardiovascular disease (along with two major risk factors, high blood pressure and elevated blood lipids), Type 2 diabetes, and many cancers. Adequate dietary fibre will support the health of your gut bacteria too - humans can't digest dietary fibre (we lack the enzymes), but the "roughage" in our diets is the ideal food for our friendly gut bugs.
Aside from the benefits around energy levels, weight management, disease risk and overall gut health that come from eating wholegrain carbs, research suggests a benefit to lifespan from consuming a moderate amount of carbohydrates, in line with current recommendations.
So, what kind of carbs should we eat? Current Ministry of Health guidelines suggest choosing at least six serves of grainy foods a day, giving preference to wholegrain and high-fibre options. That means breads made with whole intact grains, and containing at least 6 grams of fibre per 100 grams, instead of white and low-fibre breads. Some of the white breads have added fibre, often referred to as "hidden grains", but while this increases the grams of fibre on the Nutrition Information Panel (NIP) on the back of the bread bag, it doesn't have the same health benefits as a whole grain. Look for breakfast cereals with wholegrains too; these cereals will keep you full you for longer, just make sure to check the NIP for sugar and fat content. For more info on reading NIPs, check out my blog post "NIPs: where to go for the lowdown". Other examples of wholegrain foods include porridge or muesli made with rolled oats or wholegrain oats; brown rice, quinoa, barley, corn (including plain air-popped corn), millet and buckwheat.
Grainy foods aren't the only place you'll find carbs - fruits, vegetables, legumes and dairy products all contain various forms of carbohydrates (sugars, starches and fibre), and contribute to our overall health.
So instead of thinking "all carbs are evil", try thinking "wholegrains, fruits and vegetables are tasty carbs and really good for my health so I'll mostly eat them, but there are some other, less healthy and more refined carbs that I also enjoy, so I'll still eat them but not nearly as often". Like I said at the start, a bit more nuance...!
References:
Noto, H., Goto, A., Tsujimoto, T., & Noda, M. (2013). Low-carbohydrate diets and all-cause mortality: A systematic review and meta-analysis of observational studies. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3555979/pdf/pone.0055030.pdf
Oldways Whole Grains Council. (n.d.). Definition of a whole grain. [Website]. Retrieved September 7, 2018, from https://wholegrainscouncil.org/definition-whole-grain