Comment on Shukla et al. Food Order Has a Significant Impact on Postprandial Glucose and Insulin Levels. Diabetes Care 2015;38:e98–e99

We appreciated the article by Shukla et al. (1) showing that food order had a significant impact on postprandial glucose and insulin levels in obese patients with type 2 diabetes in U.S. However, we have already reported not only the same effect of eating vegetables before carbohydrates on postprandial glucose and insulin levels but also a significant improvement of HbA_1c by as much as 1.5% in outpatients with type 2 diabetes who received instructions on food order during 24 months of a randomized controlled study in 2011 (2).

Shukla et al. mentioned that a limitation of their study was that they analyzed glucose and insulin responses up to 120 min after meal ingestion. We further confirmed that consuming vegetables before carbohydrates reduced the mean amplitude of glycemic excursions (MAGE) assessed by continuous glucose monitoring in patients with type 2 diabetes (n = 19) and subjects with normal glucose tolerance (n = 21) (3). Participants were assigned to use continuous glucose monitors for 72 h while consuming isocaloric test meals of vegetables before carbohydrates and the reverse regimen on the second and the third day in a randomized crossover design. The levels of SD (−29%, P < 0.01), MAGE (−33%, P < 0.01), incremental glucose peak (−45%, P < 0.001), and incremental area under the glucose curve 0–180_min (−39%, P < 0.001) were all significantly reduced when vegetables were consumed before carbohydrates compared with the reverse regimen in patients with type 2 diabetes and even in people with normal glucose tolerance. Our findings were presented in June 2012 at the American Diabetes Association’s 72nd Scientific Sessions in Philadelphia, PA. The reduction of MAGE is important because it would be beneficial to prevent vascular endothelial dysfunction (4), oxidative stress (5), advanced glycation end products, and cognitive dysfunction in the long term.

This easy approach of consuming vegetables before carbohydrates supports the new concept of the diabetic diet, “what to eat first or last,” as opposed to concentrating on energy or carbohydrate restrictions. As one important aspect of self-management support, clinicians should consider advising patients with type 2 diabetes, and even healthy people, about food order to prevent future diabetes or cardiovascular diseases.