**3. Results**

The details of each study including the study year, country, sample size, response rate, and methodology are shown in Table 1. Table 2 lists the sample characteristics reported by mothers in each study. In all studies, the majority of mothers were married and mothers in industrialized countries, particularly in cities, had more years of education than those in developing countries, but aboriginal mothers had the lowest education levels. In Australia, there are similar sample characteristics in maternal age in the PIFS I and II studies, while the Aboriginal mothers in PABS are younger. In both Chinese studies (Xinjiang, a remote area that is located in the Northwest, and Zhejiang, an industrialized province in Eastern China) most mothers were primiparous (75.8% and 88.6%, respectively) and there were higher rates of caesarian section (44.1% and 67.0%, respectively), than in the other studies. The Himeji study that was undertaken in the central part of Japan had the highest rate of low birth weight (8.4%) and unemployment in mothers (71.4%) among the studies.


**Table 1.** Details of the infant feeding studies in Asia Pacific region.


**Table 2.** *Cont.*

Table 3 presents the median age of introducing solid foods to infants in the Asia Pacific region. Zhejiang is the earliest at 3.8 months, while Maldives and Japan were 5.5 months of age. In Vietnam, some mothers (4.8%) introduced solid foods to their infants as early as one week postpartum while the median age was approximately 4 months. Japanese mothers residing in Perth introduced solid foods earlier than those who are living in Japan. For Australian mothers the timing of introducing solid food to their infants changed over the decade between PIFS I and PIFS II with an increase in the mean age from 4.0 to 4.4 months. The most common first solid foods given to infants are rice or rice products in Asia Pacific region (Table 4) except in the Maldives where their traditional food which is made with wheat flour and fish, and Chinese migrants to Australia (egg-yolk). It is also interesting to note that over 40% of Vietnamese mothers used monosodium glutamate in the preparation of solid foods for infants [8].


**Table 3.** The median age of the first introducing solid foods (in months) by the studies.

\* Study numbers are the same as Table 1; \*\* SD = Standard Deviation; # N/A = Not available.


**Table 4.** The type of solid foods given to infants in the Asia Pacific region.

N/A = Not Applicable; # Reference [35].

Associations between the timing of introducing solid foods and breastfeeding duration were explored in each study. In Australia, in the PIFS II study, mothers who introduced solids at or after 17 weeks had 11 weeks longer duration of breastfeeding than those who introduced solids before 17 weeks (*p* < 0.001). The Japanese study also found that the timing of the introduction of solid foods was associated with the duration of "any breastfeeding" until six months of age (OR = 1.21, 95% CI = 1.10–1.33). Among Chinese migrants to Australia, mothers introduced solid foods to their infants at similar times to other Australian infants, but this was delayed when compared with mothers in home countries. In Viet Nam, significant factors associated with delayed introduction of solid food at 24 weeks were "if mother was a farmer" (OR = 0.52, 95% CI = 0.18–0.95) and "completed secondary school" (OR = 0.28, 95% CI = 0.10–0.54), whose "husband was satisfied with the infant's gender" (OR = 0.30, 95% CI = 0.17–0.53), her "mother-in-law preferred exclusive breastfeeding" (OR = 0.18, 95% CI = 0.04–0.75), or her 'friends practised exclusive breastfeeding' (OR = 0.41, 95% CI = 0.16–1.10).

#### **4. Discussion**

While the timing of introducing solid foods varies between countries, most infants in the Asia Pacific region were introduced to solids earlier than recommended by the WHO. The mean age of introducing solid foods to infants in China (Hangzhou) was 3.8 months, the earliest in these studies, while Japan and Maldives were 5.6 months, closest to the WHO recommended age. Moreover, some studies showed that the timing of the introduction of solid foods was related to not only breastfeeding duration but also maternal occupation, education background, surrounding environments including preferences of family or friends on infant feeding methods. While the timing of solid food introduction is important in reducing problems related to infant health and development, the WHO has also emphasized the importance of the quality of the foods. Solid foods given to infants are often of high volume, with low energy and nutrient density together with a low meal frequency [36]. Our review found that many countries in the Asia Pacific region used rice porridge/cereal (See Table 4) for infants' first foods since rice is culturally believed to help with digestion. Although some countries, including Japan, excluded this question for ethical reasons, other reports still described that the most common first solid foods was rice gruel [35,37]. These rice products are often of low energy and micronutrient density, including iron, zinc and calcium. In a report by Dewey and Brown [36], the WHO/UNICEF documented that energy requirements from solid foods for infants aged 6–8 months should be 269 kcal per day (1125.5 kJ) and the infants would be able to obtain sufficient energy if they were fed at least three meals with a minimum energy density of 1.0 kcal (4.2 kJ)/g. However, rice porridge has only 37.8 kcal (158 kJ) per 100 g (0.378 kcal/g), a low energy food (See Table 5) [38]. While the WHO report recommended that infants aged 6–8 months, 9–11 months, and 12–24 months should be fed at least 2–3 times, 3–4 times, and 3–4 times per day respectively, this is only applicable when energy and nutrient density is appropriate for the infants age [39]. For infants who are fed rice porridge to meet their energy requirements following the WHO recommendations, they would have to be fed approximately seven times per day. Similarly, the supply of micronutrient composition in rice products is less than the recommended nutrient intakes (Table 6). Several studies have shown that breastfed infants have better absorption of micronutrients, including iron. However, after six months of age, the quantities of micronutrients in breastmilk become inadequate over time, particularly for iron [40,41]. As this happens to both breast and bottle fed infants, the quality and timing of introduction of solid foods is important in providing adequate micronutrient intakes. In both developed and less developed countries, poor choices of solid foods may lead to nutritional deficiencies.


**Table 5.** Nutritional composition of rice porridge, rice cereal and egg yolk (value per 100 g).

Source: [38]. **\*** Note = this products was added vitamins B1, B2, B3, C, folate, iron and zinc.


**Table 6.** Recommended nutrient intakes for infants aged 7–12months and 12–24 months.

Source: [42]; Note: \* = Moderate bioavailability; # = 95th percentile absolute requirements.

In developing countries, the inappropriate introduction of solid foods at an early age may be reflected in the proportion of stunting and/or wasting in young children [43]. Breastfeeding and nutritious solid foods play key roles in promoting appropriate nutrition for their growth and development and thus the quality of solid foods need to be focused to reduce the prevalence of under nutrition or malnutrition.

A meta-analysis on the impact of nutritional interventions on infant survival, disease prevention, and stunting concluded that child stunting could be reduced by approximately one third, if nutritional interventions were provided to infants before 36 months of age [44]. It is important to emphasize appropriate nutritious solid foods given to infants at the appropriate time. Golden [45] estimated the Recommended Nutrient Intakes (RNIs) for children who are moderately malnourished, and suggested the importance of a balance in nutrients between the macro- and micro-nutrients. This study also recognised the importance of nutrient density in the developing world, as many of the earliest foods introduced to infants are high volume with a low nutrient density.

Although our study showed that Maldives almost reached the WHO recommended age of introducing solid foods (5.5 months), the stunting rate under five years old was still 19% between 2006 and 2010 [46]. A more recent study in the Maldives found that within the first seven days after birth approximately 39% and 16% of infants (*n* = 458) were fed honey and dates, respectively, suggesting that the earlier study may have underreported prelacteal and early life feeds [47]. These prelacteal and early infancy feeds were related to specific cultural beliefs, but may also have had detrimental effects on infant health and the incidence of stunting.

In Japan, the mean age for the introduction of solid foods is approximately 5.5 months, and prelacteal feeds are still common, in contrast to the WHO recommendations for exclusive breastfeeding. The first priority for mothers is to continue exclusive breastfeeding for the first six months of life and then introduce nutritious complementary foods, appropriate nutrition during the 6–24 months period is also critical for infants' nutrition and development [2]. Parents should be provided with more detailed information about introducing solid foods, including the quantity, timing, and quality of the foods through breastfeeding education since nutritional status during the first two years of life is critical in terms of their lifelong physical growth and mental development [5].

There are several limitations to consider when drawing conclusions from this study. Although these studies used almost the same questionnaire on infant feeding practices and included WHO standard infant feeding definitions, the sample selection and sizes used mean that the results may not be representative of the whole of the country. Nevertheless, similar methodology used in each study means that the main conclusions of this review can be used for nutrition education. The principal finding of the review is that most countries do not achieve the WHO goal for the timing of the introduction of solid foods. Increased promotion of optimum infant feeding guidelines is needed, including guidance for the appropriate time and manner in which solid foods are intoduced. This is an important public health message for infant nutrition in the Asia Pacific region.

### **5. Conclusions**

The review of previous observational studies using the same questionnaire on infant feeding practices in the Asia Pacific region has shown that many countries need further improvement in the timing and the quality of first feeds with solid foods. This should be in conjunction with promoting the optimal duration of exclusive breastfeeding. Rice and rice products are commonly used as the first foods in this region and are of low energy density. Without fortification they provide insufficient quantities of micronutrients. Education of not only the mothers, but also other family members, health professionals and the community should be provided in order to facilitate understanding about the importance of breastfeeding and the appropriate introduction of solid foods. Several strategies including a general prohibition of prelacteal feeding in hospitals (except in specific medical circumstances), a ban on distribution of free gifts of infant formula to mothers, and an expansion of the roles of midwives should be explored. Further studies on this topic are required for a better understanding and evaluation of growth and development, and will be able to contribute to the development of more effective strategies in pediatric nutrition in this region.
