A total of 182 participants were randomized (aged 56.3 ± 10.1 years, 43% female, education 13.2 ± 4.1 years, BMI 31.5 ± 5.3 kg/m2, fasting glucose 105.7 ± 12.8 mg/dl, and 2-h postprandial postoral glucose 135.7 ± 35.8 mg/dl). There were no significant baseline differences between those in the PREDIAS and the control group. The study lost 17 participants (9.3%) to follow-up. A dropout analysis showed no significant differences between participants who remained in the study and those who dropped out.
After 12 months, there was a significant effect on body weight (). Participants in the PREDIAS group had lost 3.8 kg of weight, whereas members of the control group had reduced their weight by 1.4 kg (P = 0.001). An intention-to-treat analysis yielded similar results (control group −1.3 ± 3.9 kg vs. PREDIAS group −3.6 ± 5.1 kg; P < 0.001). A significantly higher proportion of weight was lost by those in the PREDIAS than in the control group (4 ± 5.4 vs. 1.6 ± 4.1%, respectively; P = 0.002). Similar results were obtained regarding BMI and waist circumference.
Baseline and 12-month follow-up results in the control group and the PREDIAS group
Both groups increased their physical activity significantly, but the increase was significantly greater in the PREDIAS than in the control group. Cognitive restraint of eating behavior was significantly more increased in the PREDIAS than in the control group, and eating disinhibition was significantly more decreased in the PREDIAS than in the control group. Members of the PREDIAS group showed a significant within-group reduction on the hunger scale, but there was no significant between-group difference.
There was a significant effect of PREDIAS on fasting glucose; however, the 2-h postprandial glucose values and A1C did not change significantly between the groups. Total cholesterol and triglycerides, as well as systolic and diastolic blood pressure, were significantly reduced in the PREDIAS group, whereas in the control group there was no substantial change in these risk factors. However, the between-group difference failed to reach significance.
In both groups, psychological well-being increased, whereas anxiety and depressive symptoms decreased. However, except for anxiety, there were no significant differences between the two groups.