Does the order you eat a meal in change your blood sugar?

It changes it a lot. Fifteen participants with prediabetes ate the identical meal three times in random order. Incremental glucose peaks were attenuated by more than 40 percent when protein and vegetables came first, and the area under the glucose curve was 38.8 percent lower, compared with eating the carbohydrate first.

Data suggest that nutrient order during a meal significantly impacts postprandial glucose and insulin excursions in type 2 diabetes. Nobody had reported the effects in prediabetes, where a cheap behavioral change would matter most.

The design holds everything constant except sequence. Fifteen participants with prediabetes consumed the same meal on three days in random order. Carbohydrate came first, with protein and vegetables ten minutes later; or protein and vegetables came first, with carbohydrate ten minutes later; or vegetables came first, then protein and carbohydrate together.

Blood was sampled for glucose and insulin at seven points across the three hours after each meal. That sampling density is what lets the analysis separate the height of the peak from the total exposure and from the stability of the curve.

All three measures moved together. Incremental glucose peaks were similarly attenuated by more than 40 percent in both orders that delayed the carbohydrate. The incremental area under the curve for glucose was 38.8 percent lower when protein and vegetables came first, and postprandial insulin excursions were significantly lower in the vegetables-first condition.