Universal Journal of Public Health 11(3): 332-341, 2023 http://www.hrpub.org DOI: 10.13189/ujph.2023.110307 Analysis of Critical Beliefs in Diverse Complementary Food Intervention Using Planned Behavior Theory Wida Winarno 1,* , Sandra Fikawati 1 , Rita Damayanti 1 , Ahmad Syafiq 1 , Marthin Nanere 2 , Amadeus Driando Ahnan-Winarno 3 1 Faculty of Public Health, Universitas Indonesia, Indonesia 2 Department of Economics, Finance and Marketing, La Trobe Business School, La Trobe University, Australia 3 Indonesian Tempe Movement, Indonesia Received March 3, 2023; Revised May 21, 2023; Accepted June 11, 2023 Cite This Paper in the Following Citation Styles (a): [1] Wida Winarno, Sandra Fikawati, Rita Damayanti, Ahmad Syafiq, Marthin Nanere, Amadeus Driando Ahnan- Winarno , "Analysis of Critical Beliefs in Diverse Complementary Food Intervention Using Planned Behavior Theory," Universal Journal of Public Health, Vol. 11, No. 3, pp. 332 - 341, 2023. DOI: 10.13189/ujph.2023.110307. (b): Wida Winarno, Sandra Fikawati, Rita Damayanti, Ahmad Syafiq, Marthin Nanere, Amadeus Driando Ahnan- Winarno (2023). Analysis of Critical Beliefs in Diverse Complementary Food Intervention Using Planned Behavior Theory. Universal Journal of Public Health, 11(3), 332 - 341. DOI: 10.13189/ujph.2023.110307. Copyright©2023 by authors, all rights reserved. Authors agree that this article remains permanently open access under the terms of the Creative Commons Attribution License 4.0 International License Abstract Diverse complementary foods (DCF) play a significant role in meeting the nutritional needs of infants aged 6-23 months to avoid malnutrition. However, local beliefs (e.g., socioeconomic, and religious beliefs) can determine the success of such public health intervention programs, especially in highly diverse regions. Selecting the most critical factors in the community to undergo intervention programs is also tricky. This study investigated mothers' beliefs in providing DCF to evaluate their understanding of the importance of DCF with purposive sampling. A quasi-experimental study involving forty-one mothers in a stunting-impacted area of Bogor, West Java, Indonesia, was undertaken. Data were obtained via 3-phase interviews conducted by trained enumerators until saturation condition was reached. For the first phase, the mother's beliefs were identified using questionnaires based on the Planned Behavior theory. The second phase separated the subjects based on their beliefs in giving DCF. The third phase was determining the significance of differentiating beliefs between the groups using a statistical T-test and pinpointing the most significant concerns. Based on their practical understanding, twenty-two mothers were classified as DCFs (mothers who made and served DCF containing fresh ingredients to their infants) and nineteen as non-DCFs. The seven most differentiating core beliefs were identified: the factors of economy, children's pickiness in eating, husband's support, motivation, instant food consumption, places to shop, and availability of various foods around the house. This study demonstrated that distilling critical intervention points, i.e., core beliefs in complex public health interventions, can be done by applying the Planned Behavior theory. Keywords Beliefs, Dietary Diversity, Planned Behavior, Communication Strategy, Intervention 1. Introduction Adequate complementary feeding practices are critical for children's health, growth, and development [1]–[3]. Nutrition intake in the first two years of a baby is vital in human life [4], [5]. Inadequate food intake at months 6-23 is associated with growth faltering, resulting in increased risks of stunting [6], [7]. Babies depend on their mother or caregiver during complementary feeding periods to give them food [3]. The complementary food period is also a time for forming eating habits and developing a good appetite [6]. Caregivers' knowledge, time availability, household dynamics, and social norms determine infant and young child feeding practices [8]. The Minimum Dietary Diversity (MDD) and Minimum Acceptable Diet (MAD) provide guidelines to help children consume diverse food and are given food at an adequate frequency [9]. The World Health Organization