What kind of carbohydrates should you be eating and how much? Hannah Ebelthite finds out
Carbohydrates are one food group that’s rarely out of the diet headlines – but for reasons that are never quite clear. Do they cause weight gain in midlife and trigger our appetites? Or is a high-carb, high-fibre diet better for our health, as longevity research based on the world’s ‘Blue Zones’ (communities with a high number of extraordinarily long-lived people) suggests? The truth, says leading dietitian Helen Bond, is that despite the popularity of low-carb eating plans such as Dukan, keto and Atkins, carbohydrates are an essential part of a healthy, balanced diet. ‘They’re one of the three macronutrients – alongside fat and protein – and our bodies need lots for energy.
Carbohydrates should provide us with about 50% of our daily energy needs,’ she explains. ‘But that doesn’t mean you need to eat half a loaf of bread! Carbohydrates aren’t just in grains, they’re found in vegetables, fruit, legumes, nuts, seeds – in fact, all plant foods.’
Carbohydrates are eventually broken down by your body into sugars (glucose) and burned or stored as a source of energy. But different types of carbs do this at different rates. Simple carbohydrates (aka ‘fast’ carbs) are made up of short chains of molecules that are digested quickly. These are the type you’ll find in foods such as sweets, cake, jam and fruit juice – they’re also known as free sugars. They contain little or no fibre and, as their name implies, can cause a rapid rise in blood sugar.
The second category, complex carbohydrates (or ‘slow’ carbs), contain longer chains of molecules and are digested more slowly. Found in brown rice, pulses, wholewheat pasta, potatoes, wholegrain bread and some fruit and veg, slow carbs contain nutrients such as vitamins, minerals and fibre. Eating slow carbs also helps balance blood sugar and prevent hunger-inducing low blood sugar. And it’s these that we should concentrate on to optimise our energy in midlife.
FAST VS SLOW
Experts use the glycaemic index (GI) to rank carbohydrates, with a scoring system from zero to 100 that’s based on how fast different foods raise blood-glucose levels. It was originally developed for diabetics, but its usefulness has grown with our understanding of the impact blood-sugar levels have on hunger. Slow carbs rank lower on the GI index; fast carbs, which cause a rapid rise-and-fall in blood sugar, have a higher GI. ‘It’s particularly important for people with diabetes who need to control their blood-glucose levels,’ says Helen. ‘But choosing low GI can also help the general population when it comes to maintaining a healthy weight.’ How so? ‘The complex structure of low-GI foods means digestion is slower, resulting in a more controlled release of energy,’ says Helen. ‘
