Impact of Food Fortification on Child Growth and Development during Complementary Feeding

• Effective feeding practices at early stages of life have a positive impact on the growth and development of a child as evidenced by a growing body of literature on negative growth outcome with inappropriate feeding practices.

• Fortification of commonly used food vehicles provides an opportunity for increasing nutrient intake during infancy and has the potential to improve growth. Fortification, however, depends on relevant food vehicles during complementary feeding programs. Those food vehicles include staple foods (e.g., rice), condiments (soy sauce and sugar), and processed foods (infant complementary foods).

• Most studies still reflect outcomes that do not demonstrate direct cause and effect relationships between fortification and growth but rather evidence of implied linkages.

• Important caution dwells on the fact that fortification should be evidence based and implemented based on initial screening processes or observable clinical signs for potential deficiencies. Key players in the intervention matrix should avoid blanket or mass fortification without informed choices backed by evidence.

Effective feeding practices at early stages of life have a positive impact on the growth and development of a child. There is a growing body of literature that significantly demonstrates a negative growth outcome with inappropriate feeding practices [1, 2]. Introducing additional foods other than breast milk poses a high risk of deficiencies at the early stage of life [3] and more specific for 1,000 days.

A causal link between infant feeding practices and growth during infancy is unquestionable and many studies have had significant proof of the relationship [4‒6]. These linkages have been demonstrated particularly in both cross-sectional studies [7, 8] and longitudinal models [9]. Both designs have strong weight behind determination of causation and had a significant confirmation of the link between feeding practices and growth of a child leading to strong internal consistency.

Growth faltering is widespread during the critical formative years of child growth [10‒12] leading to both short-term and long-term consequences in relation to physical and mental development [13]. Effective complementary feeding has demonstrated an observable positive effect on the linear growth of a child within the first 24 months of life [14]. Somehow, it appears that improved complementary feeding is directly proportional to the linear growth of a child [15]. These empirical attestations confirm the need for interventions that target growth enhancement during complementary feeding.

Existing literature confirms that growth impairment can be experienced first immediately after birth and may continue all through 18 months [16, 17]. This period includes the complementary feeding phase characterized by variations across households. Growth failure may be caused by an inadequate intake of macronutrients and micronutrients [18], which is sometimes found to be common during complementary feeding. Many causes of growth retardation which occur during complementary feeding often reflected as stunting have demonstrated reversibility. The provision of multiple micronutrient supplementation during 12 months corrected child growth in Mexican children [11]. This outcome was also reflected in cognitive development [19], where micronutrient supplementation could improve cognitive indices with characteristics of impairment.

Fortification of commonly used food vehicles provides an opportunity for increasing nutrient intake during infancy and has the potential to improve growth [20]. Fortification, however, depends on relevant food vehicles during complementary feeding programs. Those food vehicles include staple foods (e.g., rice), condiments (soy sauce and sugar), and processed foods (infant complementary foods) [21]. In infants and young children, fortification has demonstrated more effectiveness than supplementation [22]. This review examines the effectiveness and impact of fortification on the growth and development of children during complementary feeding. Focus is given to physical growth, differential growth, and development parameters during infancy and childhood.

The study design adopted the use of a mini systematic review critically assessing previous empirical studies (Fig. 1). PubMed, Google Scholar, and BioMed Central were the main databases used to search for relevant articles using keywords such as “food fortification and growth” and “food fortification, growth and compensatory feeding”. Objective evaluation was applied in critical scanning of each article based on the thematic focus of the articles in relation to the topic of the study. Issues that were weighted for purposes of inclusion surrounded the complementary feeding, fortification in the context of young child feeding as well as physical and cognitive growth. The review scanned through 186 articles closely related to the topic and out of these a few articles were selected after meeting the threshold of set criteria to argue on the empirical case. The results identified milk, iodine, maize meal, and vegetable oil as the commonly used food vehicles for fortification.

Introduction of complementary foods after 6 months of exclusive breastfeeding is crucial for optimal growth and development of a child within the 1,000 golden days [23]. Complementary feeding contributes to child growth and development between 6 and 24 months [24], making it a critical factor in the etiology of malnutrition. Some studies have confirmed the existence of problems characterized by suboptimal complementary feeding practices in West Africa posing a major challenge towards the achievement of a minimally acceptable diet [25]. Given the importance of complementary feeding in the physical growth and cognitive development of a child, there appear to be serious gaps when normal diet provisions become a usual practice.

During complementary feeding, the high incidence of growth faltering is probably the result of questionable meal quality, quantity, and frequency [26]. These components of complementary feeding attempt to suggest a critical focus on the quality and adequacy of complementary foods for maximum supply of required nutrients. These results may exhibit adverse consequences on growth and development. Somehow a study of this nature seems to demonstrate a persistent positive effect on intelligence development [27]. In addition, this reaffirms the contribution of fortification to the cognitive development of children.

Fortification is one of the many public health interventions towards mitigating micronutrient malnutrition as well as poor growth and development of children [28]. Fortification refers to the deliberate addition of nutrients to food to meet the demand of increased intake requirements of a targeted population. In many cases, fortification targets restoring nutrients lost during processing, enhancing nutrients lost during processing, enhancing nutrient levels of food vehicles that have limited content than what is required, and adding nutrients not usually present in food to some commonly consumed food vehicles for the purposes of boosting intake of that particular nutrient [29, 30].

Successful fortification during complementary feeding depends on food vehicles commonly used as complements. Nearly all food vehicles used as basic minimum for complementary feeding reviewed from previous literature focus on micronutrient fortification [31‒33]. However, it is widely known in science that vitamins and minerals play a major role in metabolic processes and are very critical in macronutrient metabolism. Therefore, the hidden role in growth is unquestionable.

Complementary feeding has a significant attributable effect on child growth and thus opens up a gateway for fortification [34]. Many studies have demonstrated the impact of fortification on the physical and emotional development of children.

A study conducted to investigate whether multi-micronutrient food fortification could improve the cognition of school children through a systematic review process revealed a positive correlation and subsequent effect [35]. Similarly, another study made an attempt to test the effect of milk fortified with iodine on the cognitive ability of children, where a considerable favorable impact was realized on cognitive function of school children [36]. This relationship is not far from the truth as iodine is needed for the production of thyroid hormone that is essential for growth.

A randomized controlled study involving 419 infants aged 6 months was conducted for 9 months with a single-blind technique to establish the effect of animal source food and micronutrient fortification in complementary food products on linear growth [37]. The final outcome of this study revealed the potential of micronutrient fortification. The outcome somehow concurred with another study which demonstrated a positive effect on linear growth driven by multi-micronutrient home fortification among refugee children [38]. These two studies appear to confirm the impact fortification has on the linear growth of children during complementary feeding. However, fortification not only contributes positively to linear growth and physical development. Some studies have focused on home fortification of complementary feeding and its effect on intellectual development of children in a large sample survey (n = 1,478). In Table 1, relevant selected studies are shown to demonstrate the existing relationship between fortification, growth, and development.

A close analysis of these studies reviewed demonstrated convergence, with a common understanding of the positive correlation between food fortification and the growth of children. Growth parameters consistently range from physical, motor, to cognitive development across the studies. This review demonstrates the growing literature on the impact of fortification on growth and development during complementary feeding. It identified growth from the perspective of physical and cognitive dimensions. Micronutrients are major fortifiers in common food vehicles, which justifies that fortification is rather a metabolic process in growth and development.

The result based on articles which met the minimum selection criteria identified milk, iodine, maize meal porridge, and vegetable oils as recurring fortification vehicles in the context of complementary feeding. However, the review reflects outcomes that still do not demonstrate direct cause and effect relationships between fortification and growth but rather evidence of implied linkages. Therefore, fortification should be evidence based and implemented based on initial screening processes. Key players in the intervention matrix should avoid blanket or mass fortification without informed choices.

The author of this publication received an honorarium from Nestlé Nutrition Institute. The terms of this arrangement have been reviewed and approved by the Kenya Nutritionists and Dieticians Institute in accordance with its policy on objectivity in research.