Comparison of appetite responses to high– and low–glycemic index postexercise meals under matched insulinemia and fiber in type 1 diabetes

Background: Patients with type 1 diabetes face heightened risk of hypoglycemia after exercise. Subsequent overfeeding, as a preventative measure against hypoglycemia, negates the energy deficit after exercise. Patients are also required to reduce the insulin dose administered with postexercise foods to further combat hypoglycemia. However, the insulin dose is dictated solely by the carbohydrate content, even though postprandial glycemia is vastly influenced by glycemic index (GI). With a need to control the postexercise energy balance, appetite responses after meals differing in GI are of particular interest. Objectives: We assessed the appetite response to low–glycemic index (LGI) and high–glycemic index (HGI) postexercise meals in type 1 diabetes patients. This assessment also offered us the opportunity to evaluate the influence of GI on appetite responses independently of insulinemia, which confounds findings in individuals without diabetes. Design: Ten physically active men with type 1 diabetes completed 2 trials in a randomized crossover design. After 45 min of treadmill exercise at 70% of the peak oxygen uptake, participants consumed an LGI (GI ∼37) or HGI (GI ∼92) meal with a matched macronutrient composition, negligible fiber content, and standardized insulin-dose administration. The postprandial appetite response was determined for 180 min postmeal. During this time, circulating glucose, insulin, glucagon, and glucagon-like peptide-1 (GLP-1) concentrations and subjective appetite ratings were determined. Results: The HGI meal produced an ∼60% greater postprandial glucose area under the curve (AUC) than did the LGI meal (P = 0.008). Insulin, glucagon, and GLP-1 did not significantly differ between trials (P > 0.05). The fullness AUC was ∼25% greater after the HGI meal than after the LGI meal (P < 0.001), whereas hunger sensations were ∼9% lower after the HGI meal than after the LGI meal (P = 0.001). Conclusion: Under conditions of matched insulinemia and fiber, an HGI postexercise meal suppresses feelings of hunger and augments postprandial fullness sensations more so than an otherwise equivalent LGI meal in type 1 diabetes patients. This trial was registered at clinicaltrials.gov as NCT02208115.