Based on a recent study, the answer appears to be yes, both for those who have diabetes and those who do not.
Twenty-four individuals, 12 with type 1 diabetes and 12 without, were monitored with regard to their diet, caloric intake, physical activity, and glucose levels. All of them walked after two of their daily meals and sat after the third meal, which was randomly selected. All participants had their glucose levels measured four and one-half hours after eating. At that time, those with diabetes had a significantly higher glucose level when they did not walk. The healthy participants also had a higher glucose level after inactivity, although the difference was not as marked.
Researchers at the Mayo Clinic, who conducted the study, suggest that light exercise after meals, even something as minimal as washing dishes, may help decrease glucose levels. The possible long-term benefits for healthy people who walk or do other light exercise after meals are not clearly known, but other research has shown that walking in general has a positive effect on weight control and overall health.
Source: Diabetes Care, August 8, 2012