1. Introduction
Complementary foods, or any solids or liquids other than human milk or infant formula, are needed in order to meet nutritional requirements from approximately 6 months of age [
1,
2]. Behavioral cues of “readiness to feed” are often observed at the 4–6 month age range, correlating with when infants have physiologically developed to safely tolerate the introduction of complementary foods [
3,
4,
5,
6]. Although the World Health Organization (WHO) and the American Academy of Pediatrics (AAP) recommend exclusive breastfeeding from birth to 6 months due to its numerous benefits for both maternal and infant health [
7,
8,
9].
Early introduction of complementary foods (EIOCF) prior to 4 months of age is associated with adverse health outcomes [
10,
11]. Several recent studies agree that the introduction of foods before 4 months of age (EIOCF) or after 6 months (late introduction) is associated with higher adiposity and higher obesity risk in childhood [
10,
11,
12,
13,
14]. The proposed mechanisms for this relationship include early displacement of breastfeeding and its associated protective effects against obesity [
15], possibly explaining why adverse effects of EIOCF are seen more strongly among infants who are formula-fed [
9,
10,
16]. Other studies have proposed that EIOCF is a practice associated with other obesogenic early feeding practices [
4,
13,
14,
16]. The National Health and Nutrition Examination Survey (NHANES) and the National Survey of Children’s Health (NSCH) data have shown that between 2009 and 2018, the proportion of infants who had commenced CF before 4 months of age had doubled, with 32% of infants having had EIOCF between 2016–2018 [
17,
18]. Twice as many of these infants had been formula-fed when compared to breastfed [
18].
Caregivers’ self-reported experiences of CF are scarcely reported. A review by Spyreli et al. among parents in high-income countries, found infant behavioral cues, infant size and desire to expand familial feeding roles influenced decision-making around the timing of CF commencement [
19]. Demographic factors such as younger maternal age, lower levels of maternal education, and formula-feeding were also found to be associated with EIOCF [
10,
18,
20,
21]. Recent studies have found specific minority groups were less likely to be aware of the rationale behind CF guidelines [
6,
21]. In high-income countries, two reviews reported high levels of awareness yet limited understanding of the guidelines, with parents rejecting the guidelines as they were viewed as “too rigid” [
5,
19].
Native Hawaiian and Other Pacific Islanders (NHPI), and Filipinos are historically under-served minority groups in research [
22]. These ethnic groups have a high prevalence of diet-related health outcomes such as obesity [
23]. Non-Communicable Diseases (NCDs), including Type 2 Diabetes Mellitus (T2DM), are disparately more prevalent amongst these populations than in the general US adult population [
24,
25,
26]. Childhood obesity is reported to affect as much as 13.6% of NHPI and Filipino children aged 2–8 years, which was the highest prevalence second only to American Indians and Alaskan Natives [
23]. Oshiro et al. and Okihiro et al. investigated early rapid growth and later childhood obesity in these populations [
27]. The rate of weight gain in the first 2 years of life was positively associated with BMI at the age of 5 years, and 4–5 years, respectively [
16,
27]. Okihiro et al. proposed that a contributing factor to these results may have been early feeding practices in these populations [
16,
20]. These findings support current evidence suggesting that the first 1000 days of life is a crucial nutritional window [
28,
29]. More research into NHPI and Filipino caregivers’ CF practices may help to guide future efforts to promote optimal early feeding practices in this population.
Culture and family were identified as factors influencing caregivers’ decision-making regarding CF such as the timing of CF and the types of foods offered [
6,
19,
30,
31]. In the Native Hawaiian culture, infants were offered fresh
poi (steamed and mashed taro root) at 6 months [
32]. Fialkowski et al. found that
poi remains a staple in the diets of infants in Hawai‘i [
33]. Similarly, taro along with coconut were traditional first foods among Other Pacific Islanders [
34]. In Filipino culture, the introduction of complementary foods occurred at 6 months, with rice offered as the first food [
35]. The transgenerational experience was identified as influential in caregivers’ decision-making regarding CF in several cultural groups; including the timing and types of foods [
6,
31]. However, these studies also found that family, in particular grandparent involvement in feeding, was associated with EIOCF [
6,
20,
30]. In Native Hawaiian culture,
kūpuna (grandparents), traditionally played an important role in rearing the young, and thus had a major influence on CF practices [
32]. In contemporary times, the influence of
kūpuna in CF appears to remain pertinent [
36].
The aim of this secondary analysis was to explore the CF experience of caregivers of NHPI and Filipino infants, with a focus on the timing of the introduction of complementary foods and the role of transgenerational experience. We also investigated whether the chosen CF practices of those who exclusively breastfed were different from the practices of those who also included infant formula.
2. Materials and Methods
Prior to commencement of data collection, all participants provided written consent. The University of Hawai‘i Institutional Review Board deemed the study exempt.
This analysis was part of a larger, quantitative study exploring CF among NHPI and Filipino infants living in O‘ahu, Hawai‘i [
36]. The study took place between Spring 2018 and Spring 2019. The longitudinal study investigated CF (timing and the types of food offered) among infants 3–6 months of age, and diet diversity among those 6–12 months of age. A total of 70 infants were included in the longitudinal study [
36]. Inclusion criteria were: age (3–12 months), engagement in CF, and race/ethnicity (at least one of NHPI and/or Filipino). Convenience sampling, through community programs, community events as well as personal and professional networks, was used to recruit participants. The methods used for data collection in this analysis were semiqualitative.
For this study, the infant feeding method was quota-sampled from a subsample of participants from the larger study. The participants were divided into two groups based on method of infant-feeding: feeding human milk exclusively (HME) or infant formula and human milk combined (F&HM). The goal was to interview 32 participants (two groups of 16 participants each). Caregivers self-reported information on infant feeding. Caregivers were compensated with a gift card after the interview. Three foster care participants were excluded as their distinct situation and small sample size meant that analysis of their interviews would not elicit meaningful results for this sub-group. Therefore, only the interviews of caregivers (29 mothers and 2 fathers) of 29 infants were included in this study. Data replication and redundancy, indicating data saturation, occurred during the analysis of interview 8 [
37]. Researchers agreed that caregivers of 29 infants would elicit sufficient data through the interview responses.
A researcher-designed survey administered through a secure online web application collected demographic details of the infants and caregivers, including infant age, sex, race/ethnicity, benefits received (Special Supplemental Nutrition Program for Women Infants and Children (WIC) [WIC]/Supplemental Nutritional Assistance Program [SNAP]), feeding since birth (HME or F&HM), household size, and cultural identity. The survey responses from caregivers of the 29 infants involved in this study were descriptively analyzed.
In-depth, semi-structured interviews provided the qualitative data used in this study. The research question guiding the qualitative data collection was: what influences decision-making on first foods of NHPI and Filipino infants? The protocol used by interviewers was adapted from research by Fialkowski et al. [
35]. This protocol facilitated the interviewers’ ability to guide conversations in order to obtain relevant information and gave flexibility to acknowledge and respond to the matter at hand (such as emerging ideas). The interview involved 10 leading questions and associated follow-up questions. Participants consented for the interviews to be audio-recorded, and interviews took place at a time and private location convenient for participants.
Caregivers’ responses to a subset of 3 of the 10 leading questions related to the timing of the introduction of complementary foods and the caregivers’ transgenerational experience of CF practices were analyzed for the purpose of this study (
Table S1). Responses from caregivers who fed HME were compared to those who fed F&HM. The researchers agreed that these questions would reveal when complementary foods introduction occurred, and whether this was what caregivers were advised to do. For the purpose of this study, the CF guidelines of the WHO and AAP are used as reference for the appropriate timing of the introduction of complementary foods (from 6 months) [
7,
9]. The remaining 2 questions would provide insight into transgenerational CF practices among the NHPI and Filipino populations.
All interview transcripts were coded first, then key ideas and recurring themes were compared within and between groups. To ensure reliability, 4 interview transcripts were chosen at random, and 2 researchers analyzed and coded these according to a set codebook, using appropriate themes. A Cohen K of 0.72 was achieved after this initial round of analysis, signifying a level of moderate agreement [
38]. Discussions occurred, and the codebook updated accordingly. Another round of analysis of 4 additional transcripts selected at random was completed by the same two 2 researchers using the updated codebook. This second round of coding resulted in a Cohen K of 0.98, which signified a strong level of agreement [
38]. One researcher, using the established codebook, then analyzed the remaining 21 transcripts. The analysis of transcripts reduced the data and identified core themes and meanings [
39]. Representative quotes were used to indicate transferability and qualitative trustworthiness [
40]. Comparison of frequency of occurring themes between groups facilitated exploration of differences in infant feeding practices and behaviors. All participants were identified using study identification numbers with qualitative analysis occurring in Google Sheets.
Descriptive analysis of participants’ demographic data was carried out in IBM SPSS Statistics Version 27.0 (SPSS Inc.: Chicago, IL, USA). Although no statistical tests were used in analysis as this was not the intent of the study, findings are presented semi-quantitatively for the purpose of comparison of the feeding practices and experiences of the F&HM and HME groups.
4. Discussion
This study is the first to investigate primary caregivers’ self-reported CF experiences among NHPI and Filipino populations. The findings on the timing of CF commencement agree with existing research which suggests that the practice of EIOCF is more prevalent among formula-fed infants than among infants fed human milk [
18]. Although evidence regarding the relationship between EIOCF and later obesity is conflicting [
10,
11,
14], research suggests that adverse effects of EIOCF most strongly impact formula-fed infants, likely due to lack of exposure to the anti-obesogenic properties of human milk [
10,
21]. Current research suggests that caregivers’ understanding of CF guidelines is associated with more appropriate timing of the introduction of complementary foods [
21]. A concentrated effort is needed to ensure caregivers’ understanding of the potential health implications and safety concerns regarding EIOCF, particularly among those who feed infants formula.
The CF guidelines of the WHO and AAP recommend that CF should commence from 6 months of age [
7,
9]. However, half of the caregivers reported receiving advice from HCPs that CF can commence earlier than this. Other qualitative studies have reported similar findings regarding the inconsistency of CF advice among HCPs [
41,
42]. Mothers in one study had less trust in HCPs after advice given regarding the timing of CF commencement varied from the WHO guidelines [
41]. Despite the conflicting advice, the majority of caregivers in both groups reported following the advice of HCPs regarding the timing of CF commencement. This finding was unexpected based on research among other populations [
19,
21]. However, in order to safeguard caregivers’ trust in the advice of HCPs, consistency and clarity of CF advice is necessary [
41].
Among other traditional and cultural first complementary foods, caregivers frequently introduced poi. Poi was the most frequently offered first complementary food among infants in the larger study, of which these participants were a subsample [
36]. The introduction of poi has a traditional basis. Poi is a traditional first food offered by the Native Hawaiian population [
32]. Similarly, taro is a staple in the diet of many Other Pacific Islanders [
33]. The WHO also encourages the inclusion of culturally appropriate foods during the CF period [
7]. However, this study conveys that poi has grown in popularity across different cultural groups. This is likely because, as caregivers described, poi is readily available, and is promoted widely in the community and by HCPs. Poi is hypoallergenic due to its low protein content, easily digestible, texture-appropriate, and a source of several micronutrients (e.g., several B-vitamins, calcium, magnesium, potassium) of specific importance during the CF period [
43,
44]. The widespread use of poi as a first complementary food among the NHPI and Filipino populations can be considered an appropriate, if not a beneficial infant feeding practice that has transcended from previous generations. Some caregivers expressed that poi has become more accessible to them as a result of government-funded programs such as WIC. Recent findings by Campbell et al. similarly suggested that WIC/SNAP participation among NHPI and Filipino infants facilitates the inclusion of foods from ‘healthy’ food groups [
45].
As was anticipated based on current research, males (fathers) were reported to have a more prominent role in cooking and feeding activities than in previous generations [
46]. However, grandparents’ role in cooking and feeding was much less prevalent than is traditional for families of the NHPI population [
35]. Although, the small sample size in this study is acknowledged. This observed change in feeding roles could be related to caregivers’ frequent expressions of disagreement with CF advice offered by family members, which often contradicted that of HCPs. This is in line with current research, which suggests that grandparent involvement in feeding is associated with earlier CF [
20,
21].
Another theme that emerged was a belief among some caregivers to be more cautious when making decisions regarding CF, compared to previous generations. This belief was also identified among caregivers in another study [
6]. Likewise, some caregivers expressed distrust in pre-made infant foods and reported exclusively feeding “organic” varieties of foods, although, such beliefs are not supported by current evidence [
47,
48,
49,
50]. Similarly, most caregivers in both groups were receptive to the advice of HCPs relating to unadvised feeding practices, including pre-mastication. Pre-mastication is a transgenerational feeding practice, which holds cultural significance in the Native Hawaiian population [
35]. This practice nourishes the infant’s soul [
51]. However, due to concerns regarding links with communicable diseases [
52], some caregivers chose not to adopt this CF practice. The discontinuation of this traditional practice based on the advice of HCPs suggest that participants’ CF choices are becoming more cautious.
The limitations of the study may be that convenience sampling may have contributed to selection bias. However, the inclusion criterion minimized recall bias, as infants included were engaged in CF at the time of the study. Demographic characteristics of participants (race/ethnicity, sex, education level) were not equally represented so there is the potential for confounding results, as such demographic factors have previously been associated with the timing of solid food introduction [
10,
18,
20,
21]. Similarly, going forward, quantitative analysis of outcomes including diet-related disease and anthropometric measures (e.g., weight, length, and other body composition indicators) would allow for more definite conclusions to be drawn from research in this area. Conversely, a strength of this study is that this is the first study to investigate caregivers’ CF experience in NHPI and Filipino populations. This investigation of under-researched racial/ethnic groups will add to the current literature surrounding NHPI and Filipino populations. Investigation of other confounding factors is warranted in future larger studies among these populations. Similarly, our findings will add to existing research regarding infant feeding methods (breastfeeding and the inclusion of formula) and CF practices. The presence of infants who were exclusively formula-fed in this sample would have been beneficial, as the practices of this group could be compared to the HME and F&HM groups. Finally, the participants may have been influenced by the interviewer, by feeling compelled to give certain responses. Open-ended and exploratory questions minimized bias by generally prohibiting simple agreement or disagreement responses. A notable strength of the study was that the interviews were conducted by researchers who self-identified as the same race/ethnicity as the interviewees. This may have put participants at ease and facilitated reassurance and comfort in sharing personal experiences.