3.1.2. BMI Evolution and Lifestyle Changes

In the analysis of BMI evolution at 6 months, 66.8% of patients of follow-up had reduced their BMI (−0.89 ± 0.73 SDS), whereas 32.5% had increased it (+0.56 ± 0.53 SDS, both *p* < 0.001), reducing the mean cohort BMI in 0.41 ± 0.95 SDS compared to **baseline**

(*p* < 0.001). At 12 months, mean cohort BMI was −0.63 ± 1.16 SDS below the initial BMI (*p* < 0.001), with 72.5% of the patients at follow-up showing BMI reduction from **baseline** (−1.11 ± 0.89 SDS, *p* < 0.001). After a significant decrease in mean cohort BMI in the first year of follow-up, a partial regain was observed at the second year, with later stabilization (Figures 1 and 2).

**Figure 2.** Evolution of BMI SDS at each time-point shown as a paired comparison with patients' BMI Z-score at baseline (taking into account exclusively those continuing follow-up at each timepoint) differentiating between those with weight reduction (WR) or increasing (Non WR) their BMI. *Abbreviations:* 95% CI: Confidence Interval 95%; Non WR: Not showing weight (or BMI) reduction; WR: Showing weight (and BMI) reduction. The percentages of patients showing WR among those retaining follow-up were, respectively: 66.8% at 6 months, 72.5% at 1 year, 71.6% at 2 years, 68.0% at 3 years, 73.1% at 4 years, 78.1% at 5 years, 72.2% at 6 years and 80.0% at 7 years (See Figure 1 for the number of patients in each time point).

> The mean BMI at the end of follow-up (*n* = 980, +3.59 ± 1.87 SDS) was lower than BMI at baseline (−0.37 ± 1.25 SDS; *p* < 0.001) with 62.65% patients having achieved some degree of BMI reduction (−1.04 ± 0.88 SDS; *p* < 0.001) but with 36.43% of patients increasing their BMI despite assistance (+0.79 ± 0.93 SDS; *p* < 0.001). At the end of follow-up, 83.1% of patients still maintained their BMI above +2 SDS (obesity), with 10.3% shifting to the overweight category (BMI centile 90 to 97) and 6.6% normalizing their BMI (below centile 90).

> The percentage of patients acknowledging snacking (eating in-between meals) at their baseline visit was 81.9% and this was reduced significantly (*p* < 0.001) at their second (55.9%) and last visit (57.2%). A similar pattern was observed for compulsive eating behavior (50.6% at the second visit and 47.3% at the last visit vs. 74.0% at baseline, *p* < 0.001). Additionally, the number of patients who did not perform any scheduled physical activity prior to their enrollment was 74.7%, with this improving significantly (*p* < 0.001) at their second (53.1%) and last visits (49.8%) (Table 2).

**Table 2.** Key behavioral items at baseline and after intervention.

