We investigated if children with excess weight who submitted to two types of intervention at school for 16 months showed improvements in thyroid and glycemic function and food intake. Children (8-11 years) with a body mass index-for-age (BMI/A) of ≥1 Z score were divided into two groups: Treatment 1 (n = 73) involved motivation to adopt healthier lifestyle; Treatment 2 (n = 103) involved performing weekly nutritional education, motivational, and physical activities at school. A semi-quantitative food frequency questionnaire was used. The delta BMI/A were similar after 16 months; Treatment 1 showed higher decrease in thyroid-stimulating hormone (TSH; median (range)): -0.45 (-3.19 to 2.17) and 0.06 (-4.57 to 1.63) mIU/L, p = 0.001), FreeT3 (-0.46 (-2.92 to 1.54) and -0.15 (-2.46 to 1.38) pmol/L, p = 0.038), and FreeT4 -1.41 (-6.18 to 3.47) and -0.90 (-4.89 to 2.96) pmol/L, p = 0.018), followed by decrease in energy intake (7304 (6806 to 7840) and 8267 (7739 to 8832) kJ, Ptreatment = 0.439, Ptime <0.001, interaction group-time p < 0.001), macronutrients and sugar. A positive correlation between FreeT3 and BMI/A, and a negative correlation with FreeT4 and insulin were found at baseline (r 0.212, p < 0.01; r -0.155, p < 0.01, respectively) and follow-up (r 0.222, p < 0.01; r -0.221, p < 0.01). The decrease in overall diet and particularly sugar intake was accompanied by a greater reduction in TSH and FreeT3 in Treatment 1, demonstrating the impact of dietary intake on thyroid function.
Keywords: food consumption; insulin; thyroid status; weight excess; weight excess treatment.