Low carb diets are still very popular in many parts of the world. The problem is, many people do not seem to really understand what “carbs” actually are. Consumer research in Europe, for example, has found that only 51% of consumers can correctly identify a carbohydrate. This is not really surprising, because carbohydrates are complicated and not currently well described on food labels.
CARBS IN FOODS Carbohydrates include varieties that are digestible by humans (known scientifically as available carbohydrates):
- Oligosaccharides (e.g., maltodextrins)
- Starches (e.g., amylose and amylopectin)
- Sugars (e.g., fructose, galactose, glucose, lactose, maltose and sucrose)
And varieties that are not digestible by humans (unavailable carbohydrates):
- Dietary fibres (e.g., cellulose, gums, hemicellulose, mucilages and pectins)
They occur in relatively large amounts in a broad range of unprocessed and minimally processed foods including:
- Grains (e.g., barley, oats, rice, rye, wheat, etc.)
- Legumes (e.g., peas, beans, lentils, chickpeas, etc.)
But are also refined into processed culinary ingredients, including:
- Flours (e.g., plain wheat flour)
- Sugars (e.g., table sugar, or sucrose)
- Dietary fibres (e.g., pectin)
Unfortunately, food labelling requirements for carbohydrates are generally poor all around the world. In most nations, including Australia, New Zealand and Europe (including the UK), only total carbohydrate and total sugars are required to be listed in Nutrition Information panels. Dietary fibre is optional unless certain specific nutrient claims are made.
North Americans are provided with more information – Nutrition Facts panels must include:
- Total carbohydrate
- Dietary fiber
- Total sugars
- Added sugars
However, oligosaccharides and starches are currently not identified in any Nutrition Information/Facts panels anywhere. Unfortunately, their omission creates erroneous statements about “carbohydrates and sugars” in foods (which is of course a tautology, because sugars are a form of carbohydrate), when what people are actually trying to say is “starches and sugars” in foods. Indeed, starches and oligosaccharides are the invisible nutrients in foods, not sugars.
WHAT DOES “LOW CARB” MEAN? Many people that are following low carb diets today are in reality following low starch diets that primarily exclude or limit grains (e.g., breakfast cereals, breads, pastas, rice, etc…) and starchy vegetables (e.g., corn, potatoes, peas, etc…). Most aren’t specifically aiming to exclude dietary fibre, although a reduced fibre intake is often an unwanted side-effect.
Even the definition of a low carb diet is hotly debated. One of the more popular systems classifies diets according to the amount of total available carbohydrate they provide:
- Very low-carbohydrate diet. 20–50 grams per day or less than 10% of a 2000 Calorie (8,400 kJ diet)
- Low carbohydrate diet. Less than 130 grams per day or less than 26% of energy from a 2000 Calorie (8,400 kJ diet)
- Moderate carbohydrate diet. 130–230 grams per day, or 26–45% of energy from a 2000 Calorie (8,400 kJ diet)
- High carbohydrate diet. More than 230 grams per day or more than 45% of energy from a 2000 Calorie (8,400 kJ diet)
To put these definitions into perspective, traditional Mediterranean diets are moderate in carbohydrate and traditional Japanese diets are high in carbohydrate. Traditionally, humans have not consumed very low carbohydrate diets.
HOW MUCH CARBOHYDRATE ARE WE EATING? Many people in the developed world could be forgiven for thinking that our diets are high in carbohydrate, and should reduce our intakes. However, we know from the latest Australian Health Survey that on average, Australian adults consumed an average of 222 grams of carbohydrate per day in 2011–12, or 44% of energy from carbohydrates, putting them in the moderate carbohydrate diet camp.
ENJOY GOOD CARBS Most people in the developed world don’t need to consume a low carbohydrate diet. Enjoying a traditional dietary pattern with a long history of health, well-being and longevity, like the traditional Mediterranean diet or Japanese diet, is a better strategy – and both diets contain plenty of fruit and vegetables, something most people don’t eat enough of.
- Literature review on consumer knowledge, attitudes and behaviours relating to sugars and food labelling
- Australian Health Survey: Nutrition First Results – Foods and Nutrients, 2011-12
Alan Barclay, PhD is a consultant dietitian and chef (Cert III). He worked for Diabetes Australia (NSW) from 1998–2014 . He is author/co-author of more than 30 scientific publications, and author/co-author of The good Carbs Cookbook (Murdoch Books), Reversing Diabetes (Murdoch Books), The Low GI Diet: Managing Type 2 Diabetes (Hachette Australia) and The Ultimate Guide to Sugars and Sweeteners (The Experiment, New York).