Subclinical hypothyroidism (SH) in children and adults is a subject for discussion in terms of whether to treat it or not with respect to the short-term clinical implications and consequences of SH and in the long term. If treatment with thyroxine supplementation is not indicated, no other treatment is available. We investigated whether a lifestyle (dietary) intervention improves or normalizes SH or decreases the presence of Thyroid Stimulating Hormone (TSH) and/or tiredness. Methods: We randomized children aged 1-12 years with SH to the control group (standard care = no treatment) or intervention group (dietary intervention). The dietary intervention consisted of green vegetables, beef, whole milk and butter for 6 months. The rest of the diet remained unchanged. We measured TSH, FreeT4, Lipid profile, Body Mass Index (BMI) and Pediatric Quality of Life (PedQL) multidimensional fatigue scale scores. Results: In total, 62 children were included. After 6 months, TSH decreased in both groups without a significant difference between the groups (p = 0.98). PedQL fatigue scores for sleep (p = 0.032) and total fatigue scores (p = 0.039) improved significantly in the intervention group, compared to the control group. No unfavorable effects occurred in the lipid profile or BMI. Conclusion: The lifestyle (dietary) intervention did not normalize SH and TSH levels, but it significantly reduced tiredness. These results suggest that children's well-being can be improved without medication.
Keywords: beef; dietary intervention; fatigue; lifestyle; subclinical hypothyroidism; tiredness; vegetables; whole dairy products.