Carbohydrates are sugars and starches derived mostly from plant foods. Starches are complex carbohydrates and they come mainly from grains, legumes (dried beans, peas and lentils), and starchy vegetables, such as sweetcorn, and potatoes.

Sugars are simple carbohydrates found in fruits and berries (fructose), milk (lactose, galactose and maltose), honey, jam and table sugar (sucrose). Some fermented grains, such as those used to make beer and whisky, are also high in sugar (maltose).