Differences in maintenance of mean blood glucose (BG) and their association with response to “recognizing hunger”

BACKGROUND Meals begin and end subjectively. We trained healthy subjects to recognize initial hunger as a preprandial target for meal consumption, and to create a "recognizing hunger" or initial hunger meal pattern. OBJECTIVE Training subjects to "recognize hunger" lowers blood glucose (BG) and improves energy balance, and lowers metabolic risks and bodyweight. A minority may have low BG and low metabolic risks at recruitment, but the others may recover this favorable condition by training. METHODS In a 7-day food diary, subjects reported their preprandial BG measurements; BG and energy availability by blood were assessed at the lowest BG during the day, and diary-mean BG thus characterized the individual meal pattern (daily energy intake). We analyzed the same diaries of a recent paper on a global, randomized comparison of subjects trained in "recognizing hunger" with control subjects. This time, we checked whether subjects who had maintained low BG (LBG subgroup) at recruitment were able to decrease mean BG and metabolic risk factors during "hunger recognition" like those who presented high BG (HBG subgroup). RESULTS At recruitment, the BG means of 120 investigated subjects were within mean confidence limits of ± 3.84 mg/dL, and we could stratify subjects in ten small strata of which each significantly differed by mean BG. Mean BG was stable in each control subject over five months; the mean absolute change being 6.0 ± 4.6 mg/dL. Only three out of 34 trained subjects who had lower mean BG than 81.8 mg/dL significantly decreased mean BG, whereas 41 out of 55 subjects whose mean BG was greater than 81.8 mg/dL significantly decreased mean BG after training (P < 0.0001). At recruitment, the LBG subgroup showed significantly lower insulin, lower BG area under curve (AUC) in the oral glucose tolerance test (GTT), and lower HbA1c than the HBG group. After training, only HBG subjects, compared with HBG controls, significantly decreased preprandial BG from 91.6 ± 7.7 mg/dL to 81.0 ± 7.7 mg/dL, in association with a decrease of HbA1c from 4.81% ± 0.44% to 4.56% ± 0.47%, of GTT insulin AUC from 244 ± 138 mU/L to 164 ± 92 mU/L, and of energy intake from 1872 ± 655 kcal to 1251 ± 470 kcal (P < 0.001), with an increase of indices of insulin sensitivity from 5.9 ± 3.3 to 9.8 ± 5.6 and of beta cell function from 1.0 ± 0.7 to 1.4 ± 1.1 (P < 0.05). LBG subjects only decreased weekly-diary BG standard deviation in comparison with controls. CONCLUSION At recruitment, the 120 subjects maintained mean BG at one personal level of ten possibilities, and 34 subjects were below 81.8 mg/dL (LBG) and 55 were over (HBG). The 55 HBG subjects showed higher mean insulin resistance, HbA1c, other cardiovascular risk factors, and increased bodyweight compared with the 34 LBG subjects. A total of 41 out of the 55 HBG subjects regressed to LBG with training.