Understanding blood sugar responses: moderation and meal composition matter more than eliminating carbs

New insights highlight that managing blood sugar levels involves focusing on portion sizes and meal composition, rather than banning all sugars or starches, with experts emphasizing moderation and understanding different carbohydrate types.

For people watching blood sugar, the issue is less about whether a food tastes sweet than how the body processes it. In a response to a reader, Dr. Roach explained that sugars, starches and fibre are all carbohydrates, but they behave differently once eaten. The practical point, he wrote, is that neither starch nor sugar has to be eliminated entirely; what matters is portion size and what else is on the plate.

The distinction begins with chemistry. Sugars are small molecules, while starches are long chains of glucose. As MedlinePlus and the National Center for Biotechnology Information explain, starches are broken down during digestion into glucose, which is then absorbed into the bloodstream. That is why refined starches such as white bread, white rice and many pastas can raise blood sugar quickly, sometimes almost as fast as table sugar.

Fibre changes that picture. Because it is not digested in the same way, it slows absorption and softens the blood sugar rise. Health sources from UCLA and WebMD note that whole-grain foods, vegetables and other fibre-rich items are generally less likely to cause sharp spikes than refined carbohydrates. Protein and fat also slow digestion, which is why a mixed meal usually has a gentler effect than a lone serving of bread, rice or potatoes.

That is why the answer to the reader’s question is no: people with prediabetes or diabetes do not need to banish all sugar or starch. What matters is moderation, the type of carbohydrate and whether it is eaten with other foods. Dr. Roach also suggested asking a doctor about a continuous glucose monitor, which can show in real time how individual meals affect blood sugar.