*Strengths and Limitations*

Accurate quantification of dietary intake in free-living populations is a major challenge in nutritional epidemiology. Moreover, there is a strong debate over the validity of memorybased dietary assessment methods utilized in epidemiological research related to food group consumption and major events of disease [72]. In the present study, to evaluate the

food consumption and estimate the nutrient intake, both a FFQ and a 24-hDR were used in a homogeneous sample of Spanish children from the same area and sharing the same socio-cultural habits. Because of its standardized format and the way these questionnaires are administered, they are methods with high performance in terms of cost-effectiveness, which has contributed to their widespread use in large epidemiological cohort studies and also with other designs. However, they have the disadvantage of incorporating systematic errors and biases, which is why procedures are currently being sought to improve the quality of the data collected [73].

This highlights that nutrient intakes variance is usually augmented due to day-to-day variation in individual intake, resulting in misleading estimates of low or high intakes [74]. To avoid the intra-individual variability of the data and obtain an estimate of the population's usual intake distribution, repeated 24-h-DR must be used.

The use of validated tools for the assessment of DPs is limited. It has been suggested that the assessment of DPs, including their consistency and construct validity, should be evaluated over multiple administrations of the same dietary source, different dietary sources, or across various studies [75,76]. In the present study, we used both PCA and clustering analysis for the estimation of DPs. Based on the available evidence, most identified DPs showed good reproducibility, fair relative validity, and good construct validity across different statistical solutions [75].

One of the major limitations of our study is that we focused on a specific population of ASD children living in the southern of Spain. Therefore, our results should be crossvalidated in other regions of Spain and other countries. Likewise, the sample of ASD children was very homogenous with regard to cultural and socio-economic aspects; thus, we cannot establish whether different eating patterns would affect nutrient intake adequacy. Finally, we did not attempt to evaluate gastrointestinal symptoms that could affect DPS and nutrient intakes.

#### **5. Conclusions**

In the present study, we reported differential DPs between children with ASD and children from the control using both PCA and hierarchical clustering analysis. This highlights high energy and fat consumption and frequently manufactured products with poor nutritional quality and a low intake of vegetables and fruits in ASD children. Likewise, this work adds further support to previous studies identifying inadequate micronutrient intakes for minerals like iron, iodine, and vitamins of group B. Adequate monitoring of the nutritional presence for these nutrients should be assessed and, if necessary, the use of supplements should be introduced into the diet. Hence, it seems relevant to assess the DPs and nutrient intakes in children with ASD to correct eating behavior disorders and rule out nutritional diseases.

**Author Contributions:** A.R.G.-F., M.G.-C. and J.L.P.-N., contributed to the study conception and study design. M.G.-C. and J.L.P.-N. coordinated all the study. A.R.G.-F., K.F.-R., P.M.-B. and M.J.d.l.T.- A. collected all the data, acquired the behavioral data, and assisted with regulatory responsibilities and carried out the analysis. J.P.-D. and M.J.d.l.T.-A. realized statistical analysis. J.P.-D., M.G.-C. and A.G. were responsible for the interpretation of the data, as well as drafting the manuscript. All authors have read and agreed to the published version of the manuscript.

**Funding:** This study was supported by the FUNDACIÓ AGRUPACIÓ Àmbit de la Infància, 404 Research Grant INVEST from the Spanish Society of Pediatrics and Red de Salud Materno Infantil (RED SAMID). Á.G. was co-financed by the Research Plan of the Vice-Rectorate of Research and Transfer of the University of Granada, Spain. The funding bodies did not have any role in the design, collection, analyses, or interpretation of data or in writing the manuscript.

**Institutional Review Board Statement:** The present work is framed within a broader research project, developed by the Pediatric Research Unit of the Pediatric Service of the Reina Sofia University Hospital of Cordoba, entitled "Monitoring of biomarkers of inflammation, oxidative stress, intestinal microbiota, and heavy metals in Autism Spectrum Disorder in childhood." This study was approved by the Ethics Committee of the Reina Sofia University Hospital of Cordoba, Spain, and follows the rules of Law 14/2007 on Biomedical Research and the Organic Law 15/1999, RD 1720/2007 on the protection of personal data as well as international rules for research using samples from human beings. Part of this project's results has been published elsewhere [52,77–79].

**Informed Consent Statement:** The participants' parents or legal guardians accepted their inclusion in the study, signing the approved protocol. The confidentiality of the data obtained and any personal data used in this study have been kept and respected.

**Data Availability Statement:** The datasets generated during and/or analyzed during the current study are available from the corresponding author upon reasonable request.

**Acknowledgments:** The authors would like to thank the children and their parents for their participation in the study. Julio Plaza-Diaz and Angel Gil are part of the UGR Plan Propio de Investigación 2016 Excellence actions: Unit of Excellence on Exercise and Health (UCEES), University of Granada. Julio Plaza-Díaz is supported by a grant to postdoctoral researchers at foreign universities and research centers from the "Fundación Ramón Areces", Madrid, Spain.

**Conflicts of Interest:** The authors declare no conflict of interest.

#### **References**

