Carbohydrates are broken down into glucose, which cells use for energy. They fall into three broad groups: sugars (simple, fast-digesting), starches (complex, slower-digesting), and fibre (mostly indigestible, vital for gut health).
Wholegrains, legumes, vegetables, and fruit deliver carbohydrates alongside fibre, vitamins, and minerals — these are nutritionally very different from refined carbohydrates like white flour or added sugar, despite providing similar calories per gram.
Most healthy adults need carbohydrates to make up roughly 45–65% of total energy (ICMR-NIN guidelines). Very low-carbohydrate diets can be effective for some people in the short term — see the Indian keto diet guide for context — but are not necessary for good metabolic health and may be harder to sustain. The quality and source of carbohydrate matters as much as the quantity.