Purpose Changes in blood glucose levels have been shown to influence eating in healthy individuals; however, less is known about effects of glucose on food intake in individuals who are obese (OB). The goal of this study was to determine the predictive effect of circulating glucose levels on eating in free-living OB and normal weight (NW) individuals. Methods Interstitial glucose levels, measured with a continuous glucose monitor (CGM) system, were obtained from 15 OB and 16 NW volunteers (age: 40 ± 14 and 37 ± 12 years; weight: 91 ± 13 and 68 ± 12 kg; hemoglobin A1c: 5.1% ± 0.7% and 5.2% ± 0.4%, respectively). While wearing the CGM, participants filled out a food log (mealtime, hunger rating, and amount of food). Glucose profiles were measured in relation to their meals [macro program (CGM peak and nadir analysis) using Microsoft® Excel]. Results OB and NW individuals showed comparable CGM glucose levels: mean [OB = 100 ± 8 mg/dL; NW = 99 ± 13 mg/dL; P = nonsignificant (NS)] and SD (OB = 18 ± 5 mg/dL, NW = 18 ± 4 mg/dL; P = NS). Obesity was associated with slower postprandial rate of changing glucose levels (P = 0.04). Preprandial nadir glucose levels predicted hunger and food intake in both groups (P < 0.0001), although hunger was associated with greater food intake in OB individuals than in NW individuals (P = 0.008 for group interaction). Conclusions Premeal glucose nadir predicted hunger and food intake in a group of free-living, healthy, nondiabetic NW and OB individuals; however for a similar low glucose level stimulus, hunger-induced food intake was greater in OB than NW individuals.
