Food Safety Focus (78th Issue, January 2013) – Food Safety Platform
Macronutrients in Infant Formula
Reported by Ms. Melissa LIU, Scientific Officer,
Risk Assessment Section,
Centre for Food Safety
This article is the first of a series of four articles that focus on nutrients in formula products and foods for infants and young children.
Nutrition for Infants
Infants must obtain optimal nutrition from their diet for growth, tissue repair and maintenance of good health. Breastmilk is a natural source of nutrients and is the best food for infants to wholly fulfil their nutritional requirements before introducing complementary diet. However, when breastfeeding is not feasible, infants would need to rely on an imitated product, i.e. infant formula, as their nutrient source.
Energy in food provides fuel needed for daily activity, growth and development. It comes from carbohydrates, fat and protein, with carbohydrates being our primary source of energy. Getting sufficient carbohydrate intake enables normal and efficient use of dietary fat and protein in the body for other essential functions such as building new tissues.
Fat provides essential fatty acids for normal brain and eye development and absorption of the fat-soluble vitamins. Fat stored in the body also reduces body heat loss and protects body organs. Protein is required for maintaining and repairing body tissues as well as producing hormones, antibodies and enzymes.
Excessive nutrient intake may lead to health concerns. For example, taking too much protein may increase the burden to the kidney. Excessive energy intake may lead to obesity. Childhood obesity is a significant public health issue in Hong Kong. A study published last year by the Department of Health revealed that 12.7% and 2.7% of children aged 0-5 years were "having possible risk of overweight" and "overweight or obese" respectively.
Formula Feeding and Overweight
Energy and nutrient requirements of infants depends on many factors, including age, body size and growth rate. Breastfed infants are normally capable of regulating their food intake to match their energy needs. Mother's body can also produce breastmilk with composition tailored to the infant's energy and nutritional requirements at different stages of growth.
In contrast, infant formulae have standardised nutrient contents to cater for the needs of average infants as a whole and may provide excessive energy and nutrients, such as protein, to some infants depending on their stage of development. Besides, bottle feeding often encourages infants eat more than what they should have. Therefore, some studies have suggested that formula-fed infants and young children are more likely to be overweight. According to the above-mentioned study, over 90% of children aged 12-24 months kept drinking formula as their sole source of milk intake, and 77% of the children still used formula at 48 months. This has aroused local concern on over-dependence on formula use, which might occur as a result of parents' misconception over the "superiority" of formula milk.
Benefits of Breastfeeding
The superiority of breastfeeding in ensuring physical and psychosocial health and wellbeing of mother and child is widely recognised. Apart from providing a tailored source of nutrients, breastmilk contains natural antibodies, living immune cells, enzymes, etc. which aid digestion and absorption of nutrients, and improve babies' immunity. On the contrary, there is currently no sufficient clinical evidence showing that the health of formula-fed infants is comparable with that of breastfed infants. As such, the World Health Organization has recommended infants to be exclusively breastfed for the first six months of life, and thereafter receive complementary foods while breastfeeding continues for up to two years of age or beyond.
Protecting the Health of Formula-fed Infants
Codex has established standards on infant formula products to ensure they have appropriate composition. The Government is currently putting forward a legislative proposal to regulate the nutritional composition and labelling of formula products and foods for infants and young children below the age of 36 months, with reference to Codex standards and international practice. It is hoped that by enhancing the local legislative control on these products, we can better protect the health of infants and young children in Hong Kong.