Objective: This paper aims to establish a potential reference standard for the process of transition from milk to solid food in infants and preschool children in Japan, using the transitional food process (TFP) scale described by Sakashita et al. The background for variation and delay in the process are also discussed.
Design: A randomized sample survey covering entire Japan.
Setting: Mailing self-completion of questionnaires.
Subjects: Randomized sample of 14 000 children aged 0-6 y and their family from 13 prefectures in Japan, namely Hokkaido, Aomori, Iwate, Niigata, Tokyo, Saitama, Fukui, Nagano, Nagoya, Hyogo, Yamaguchi, Kagoshima, and Okinawa.
Methodology: Questionnaires requesting the TFP scale and background factors were sent to 14,000 children and families. The percentile ages were calculated. An eating ability index (EAI: number of accepted foods/total number of foods) x 100) was calculated. Regression analysis by analysis of covariance (ANCOVA; SPSS, 1997) was used to determine the influence of background factors on EAI.
Results: From the 6747 (48.2%) effective answers received, percentile curves of the acceptability of each food on the scale were drawn, and used as initial reference standards. The 50 percentile age range of these 20 standard foods covers from 5 to 42 months after birth. The sensitive period for increasing the acceptance of foods in children was between 6 months and 2(1/2) y of age. ANCOVA regression model (R2=0.605) showed that EAI was mostly influenced by age (P=0.000), followed by feeding style (P=0.000), infant food preparation (P=0.000), information source (P=0.000), and birth order (P=0.003). The dominant cause of digestive system problems was shown to be infection, not too-hard food. It seems that breast feeding, bottle feeding with chewing-type nipples, and the manner of preparing infant foods from the family table promote the progress in acceptance. Children whose mothers followed the information given in books or magazines showed a slower progress.
Conclusions: It seems appropriate to use this reference standard in the study of the transitional process from milk to solid food in infants and preschool children in Japan.