Are you carb-intolerant?
As touched on earlier, some experts argue that not all our bodies process carbs with the same efficiency. ‘There’s no one-size-fits-all rule,’ says Bannock. ‘We’re all unique, so nutrient needs are individual.’ Some can tolerate and utilise carbs more efficiently, and in larger quantities, while others can’t process them as effectively, and may end up storing the large quantities they consume as fat, negatively affecting weight and ultimately health.
‘This is the key issue,’ says Noakes. ‘Clearly some athletes, such as the great Kenyan runners, are able to run very well when eating high-carbohydrate diets and it would probably be inappropriate to change their choice. This does not mean that everyone is able to metabolise carbohydrate as effectively as they are.’
So how do you know whether or not your body can tolerate those jumbo jacket spuds and super-size spag bols? ‘If, as a runner, you are clinically overweight with a body mass index greater than 25, you might be carbohydrate-intolerant,’ says Noakes. ‘And then all that carbohydrate is simply making you fat, not fit.’
‘It’s easy to see if you are carb-intolerant,’ adds Bannock. ‘If you have extra fat – you can pinch more than an inch – and you eat a lot of carbs, the likelihood is that your body is not using the carbs you take in as fuel, but storing them as fat. Many runners are “skinny fat” – they’re storing more fat around their middle and, to a lesser extent, around the hips and thighs, which can signify carb-intolerance,’ he adds.
Aside from the warning signs of weight and body fat, there’s another simple strategy to discover your body’s carb-metabolising efficiency. ‘Simply reduce the amount of carbohydrates you are eating and note the response,’ says Noakes. How does the menu change affect your body composition, performance and energy levels?
‘It needs to be a long-term change,’ warns Bannock. ‘You can expect to feel tired when you first stop eating high-carb meals, but after a few weeks you will notice a difference. A cyclist I’ve been training who ate nothing but carbs recently made the switch, and after just two weeks he got a PB.’