This study aimed to develop a specific instrument to evaluate food neophobia focused on Brazilian children and to perform the content validation and internal semantic consistency and reproducibility evaluation of the instrument. Three steps were necessary to conduct the study: (i) development of the instrument, (ii) internal validation (content validation and semantic evaluation) of the food neophobia instrument using 22 experts in the first round and 20 of them in the second round, (iii) evaluation of the internal consistency and reproducibility of the instrument with the children’s caregivers, using the test–retest (where the same caregiver—n = 22—answered twice, with 24 h interval) and comparing responses between two caregivers (n = 44) of the same children (n = 22). We developed an instrument in Brazilian–Portuguese to evaluate children’s food neophobia based on the caregivers’ perceptions with 25 items divided into three domains (neophobia in general, neophobia for fruits and neophobia for vegetables). Our results indicated that the instrument has excellent internal consistency (>0.9) and reproducibility (>0.9) when answered by the caregiver who knows the child’s eating habits, indicating reliability to be applied in Brazil. In addition, when the two caregivers answered the instrument, we found a good reproducibility (>0.6), confirming the possibility to be answered by one of the caregivers. Further studies are necessary to complete external validation with a representative sample of the target group in Brazil, showing nationwide the profile of the population. The potential of a neophobia study would contribute to the implementation of effective strategies and guidelines to support parents and health professionals, especially those involved in health and nutrition, to identify traces of food neophobia or neophobic behavior. By accurately measuring food neophobia in children, families can prevent nutritional deficiencies throughout adolescence and adulthood, improving eating habits. Children usually have neophobias similar to the ones presented by their parents—and when early detected, these neophobias can be addressed.

Food neophobia (FN) is common among children with autistic spectrum disorder (ASD), potentially impairing their health and diet quality. This study aimed to investigate and classify the prevalence of FN among 4-to-11-year-old Brazilian children with ASD. This descriptive cross-sectional study was performed by applying online a validated instrument to identify FN in Brazilian children with ASD through their caregivers’ responses for a national prevalence of FN in this group. The final sample included 593 children with ASD, 80.1% of boys, with a mean age of 6.72 ± 2.31 years, and 83% having only ASD. Almost 75% (n = 436) of the children with ASD had high food neophobia scores. The fruit neophobia domain had the lowest prevalence of high neophobia (63.7%). No significant difference in FN (total, fruit, and vegetable domains) was found, considering gender and age. There was no statistical difference in FN (all domains) by the number of residents in the same household, income, or the caregivers’ educational level. FN did not decrease in older children with ASD. FN is a more complex problem, requiring a multidisciplinary trained team to face the problem.