Impact Of Sedentary Time And Habitual Glycemic Load On Glucose Responses From A 12-week Dietary Lentil Intervention

Increased sedentary time is linked to decreased glycemic control, whereas higher insoluble fiber intake is linked to improved glycemic control. Dietary strategies to include fiber-rich foods, such as lentils, can help glycemic control to prevent and manage metabolic diseases such as type 2 diabetes. We assessed how sedentary time and habitual glycemic load (HGL) relate to glucose in high-risk individuals with an elevated waist circumference (WC) from 12 weeks of lentil consumption. PURPOSE: To examine the effects of sedentary time and HGL after 12 weeks of lentil consumption on glycemic response to a meal. METHODS: Adults with increased WC (women >35”, men >40”) aged 22-69 years consumed 0 (CON, n = 8) or 140 g of lentils (LEN, n = 7) daily as a mid-day meal for 12 weeks. A high-fat meal challenge (50 g FAT, 54 g CHO, 12 g PRO) was repeated before and after the diet, with blood collected at fasting and hourly for 5 hours after the meal. Blood glucose was summarized as integrated area under the curve (iAUC). HGL was gained through an online recall diet history questionnaire. An accelerometer was worn for the first and last week of the intervention, with continuous sedentary behavior expressed as percent of day spend in sedentary time (%ST). A linear mixed effects model assessed the impact of the meal intervention and an interaction between HGL and PST on GLU iAUC. RESULTS: There were no differences in mean HbA1c (p = 0.29), fasting glucose (p = 0.89), body mass index (p = 0.93), and WC (p = 0.94) between CON (n = 8) and LEN (n = 9). Average %ST was 61.6 ± 8.8% for CON and 52.7 ± 11.8% for LEN but did not differ by meal group (p = 0.09). The joint influence of %ST and HGL was an important predictor of GLU iAUC (β = 0.03, p = 0.03), with participants who had greater %ST and higher HGL in their diet having greater GLU iAUC. GLU iAUC did not change after 12 weeks of lentil consumption (p = 0.14); however, a main effect for time was observed (p < 0.001). CONCLUSIONS: Greater %ST lead to higher GLU iAUC in individuals with higher HGL diets, suggesting that reduced PST is important for improving glycemic responses. The combined effect of reducing sedentary time and increasing dietary fiber may be more important for GLU iAUC than increasing fiber consumption alone. Supported by USDA-ARS Pulse Crop Health Initiative 58-3060-9-040