The post-meal walks control blood sugar as well as one long walk, research by George Washington University suggested.
Elevated blood sugar after meals could increase the risk of type-2 diabetes, so resting after eating “is the worst thing you can do”, the study said.
Diabetes UK said there were “small differences” between exercise routines – but any activity was beneficial.
The US study was the first to test short bouts of exercise in the “risky period” following meals, when blood sugar can rise rapidly, lead author Loretta DiPietro said.
She said high blood sugar after meals was a key risk factor in the progression from impaired glucose tolerance – what the study called “pre-diabetes” – to type-2 diabetes and cardiovascular disease.
The study found three 15-minute walks were as effective at reducing blood sugar over a 24-hour period as one 45-minute walk of the same “easy-to-moderate” pace.
But walking after food was “significantly more effective” at “blunting the potentially damaging elevations in post-meal blood sugar commonly observed in older people”.
They found the best time to walk was after the evening meal, which is often the largest of the day and therefore causes the greatest rise in blood sugar.