Diabetes is most common among Maori and Pacific Islanders - they're three times as likely to get it as other Kiwis - and the number of people with both types of diabetes is rising, especially obesity-related type 2 diabetes.
In the research, published today in the international journal Diabetologia, 41 patients were asked to walk in two-week blocks, separated by a month.
The patients were also fitted with accelerometers to measure their physical activity and devices that measured their blood sugar every five minutes.
They walked either the advised 30 minutes each day, or for 10 minutes after each main meal.
Results ultimately showed post-meal blood sugar levels dropped 12 per cent on average when the participants followed the walking after meals advice compared to walking at any time of the day.
"Most of this effect came from the highly significant 22 per cent reduction in blood sugar when walking after evening meals, which were the most carbohydrate heavy, and were followed by the most sedentary time," said study author Dr Andrew Reynolds, of Otago's Department of Human Nutrition.
Corresponding author Professor Jim Mann said post-meal glucose was regarded as an important target in managing type 2 diabetes, given its independent contribution to overall blood sugar control and cardiovascular risk.
The researchers wrote that the approach may avoid the need for an increased total insulin dose, or additional mealtime insulin injections that might otherwise have been prescribed to lower glucose levels after eating.
"An increase in insulin dose might, in turn, be associated with weight gain in patients with type 2 diabetes, many of whom are already overweight or obese."
They conclude that the newly-proven benefits should mean current guidelines be amended to specify post-meal activity, particularly when meals contain a substantial amount of carbohydrate.
A second UK-based study in the same edition of the journal further showed increasing your amount of activity confers greater benefit in blood sugar control.