Table 2. Main results of the studies selected for the systematic review.

Reference	Key Results	Indicators analyzed
Aldámiz-Echevarría et al. 28	Overweight in the PKU group: 9.2% Overweight in the reference population: 17.4% Obesity in the PKU group: 6.5% Obesity in the reference population: 9.8%	Z-scores of weight, height and BMI.
Bélanger-Quintana and Martínez-Pardo 25	Mean Z-scores for height, weight and BMI were approximately zero for all patients with PKU. There were no statistically significant differences in height, weight and BMI Z scores at any age when compared to sex and age reference values.	Z-scores of weight, height and BMI.
Burrage et al. 27	Overweight in the PKU group: 12% Overweight in the reference population: 14.8% Obesity in the PKU group: 28% Obesity in the reference population: 16.8%	Z-scores of weight, height and BMI.
Albersen et al. 10	The mean body fat percentage was significantly higher in patients with PKU compared to healthy controls (25.2 ± 7.3% versus 18.4 ± 5.8%; p=0.002).	Weight, height, BMI and body composition assessment.
Doulgeraki et al. 29	Higher mean BMI Z-scores and body weight of individuals with PKU were observed compared to the control group. There was also a significant increase in fat mass in adolescents with PKU compared to prepubescent patients.	Z scores of weight, height, BMI and a body composition assessment.
Rocha et al. 26	Overweight in patients with PKU: 32.6% Overweight in the controls: 24.1% Mean body fat (%) in CNS patients and controls were similar: 22.0% (95% CI 14.4-28.9) versus 23.1% (95% CI 16.3-28.9); p = 0.581.	Z scores of weight, height, BMI and a body composition assessment.

PKU: phenylketonuria; BMI: body mass index; 95% CI: 95% confidence interval.