Wholesome foods may still cause quick blood sugar spikes, warns Taiwanese dietitian

A Taiwanese dietitian highlights how foods perceived as healthy, including white rice porridge and wholemeal bread, can unexpectedly raise blood sugar rapidly due to their processing and cooking methods, urging a focus on food structure over taste alone.

A dietitian in Taiwan has warned that some foods widely seen as light, natural or healthy can still push blood sugar up quickly, with white rice porridge, instant oats and wholemeal bread among the breakfast staples that may catch people out.

Yang Sihan said the glycaemic index, or GI, is a way of judging how fast carbohydrate foods raise blood sugar. According to the Mayo Clinic, Harvard Health and the Cleveland Clinic, foods are generally classed as low GI at 55 or below, moderate GI at 56 to 69 and high GI at 70 or above. But the clinic also stress that GI is only one part of the picture, because portion size, food combinations and individual differences all affect blood-sugar response.

Yang said the main reason some apparently wholesome foods act like “hidden traps” is not added sugar but the way they are made or cooked. Foods that are very soft, finely processed, highly mature or heavily cooked are often digested more quickly, which can make glucose rise faster after a meal. She listed white congee, mashed potatoes, puffed rice snacks, instant cereals, instant oats, wholemeal toast, watermelon, ripe bananas and pumpkin puree or pumpkin soup as examples that can behave this way.

The broader nutrition advice from Mayo Clinic and MedlinePlus is to focus less on whether a food tastes sweet and more on how it is eaten. Choosing less-processed foods, keeping some chewing texture, limiting starchy portions and pairing carbohydrate with vegetables and protein can help blunt sharp rises in blood sugar. Yang’s message was simple: sweetness is not the only warning sign, and a food’s structure can matter as much as its taste.