Methods: In a randomized, cross-over trial, eight participants with T1D being treated with automated insulin pumps (five females, age: 47 ± 16 years, BMI: 27.5 ± 3.8 kg·m2, diabetes duration: 23 ± 11 years, HbA1c: 8.3 ± 0.9 [67.5 ± 9.5]% [mmol/mol]) attended the laboratory on two separate occasions and consumed an isocaloric amount of isomaltulose as either (1) a single serving (0.75g CHO·kg−1 BM) with a 25% reduction in bolus insulin 90 min before 45 min of cycling (PEC) or (2) three separate isocaloric servings (0.25g CHO·kg−1 BM each) without bolus insulin during exercise (DEC). The gene discussed is INS; the disease is diabetes mellitus.