To cut diabetes risk, walk after every meal: study

Blood sugar spikes after meals. In young, fit people, insulin helps drive that sugar, or glucose, into muscle cells and the liver, where it's stored for energy. But the system is less efficient as we get older, and leaving too much glucose in the blood can lead to type 2 diabetes and cardiovascular damage.

While prior research already confirms that exercise, including 45-minute daily walks, can reduce your risks for type 2 diabetes, researchers wanted to see if shorter walks could also be as beneficial, especially for older inactive people.

Researchers at the George Washington University School of Public Health and Health Services in the US found that three short post-meal walks were as effective at reducing blood sugar over 24 hours as a 45-minute walk of the same easy-to-moderate pace.

Moreover, post-meal walking was significantly more effective than a sustained walk at lowering blood sugar for up to three hours following the evening meal, the researchers said.

The study is published June 12 in Diabetes Care.

"These findings are good news for people in their 70s and 80s who may feel more capable of engaging in intermittent physical activity on a daily basis, especially if the short walks can be combined with running errands or walking the dog," said lead study author Dr. Loretta DiPietro.

"The muscle contractions connected with short walks were immediately effective in blunting the potentially damaging elevations in post-meal blood sugar commonly observed in older people," she said.

DiPietro and her colleagues recruited 10 people age 60 and older who were inactive and at risk of developing type 2 diabetes. Participants completed three randomly ordered exercise protocols spaced four weeks apart. Each protocol comprised a 48-hour stay, with the first day serving as a control period. On the second day, subjects engaged in either post-meal walking for 15 minutes after each meal or 45 minutes of sustained walking performed at 10:30 am or 4:30 pm. All walking was performed on a treadmill at an easy-to-moderate pace. Participants ate standardized meals and their blood sugar levels were measured continuously over each 48-hour stay.

Findings showed that the best time to take a post-meal walk is after the evening meal, which is often the largest of the day and high post-dinner blood sugar is a strong determinant of excessive 24-hour glucose levels, the researchers said.

While most people eat a large meal either at lunch or at dinner and then take a nap or watch television, DiPietro says this is the "worst thing you can do." She adds: "Let the food digest a bit and then get out and move."

Still, she adds that because of the small size of the study, results need to be confirmed with larger trials that include more people.