Programming for a Healthy Life by Complementary Feeding?

Childhood Nutrition Research Centre
UCL Institute of Child Health
London, UK
m.fewtrell@ucl.ac.uk

• Complementary feeding practices could potentially influence later health outcomes by programming effects, but also by lasting effects on food preferences, appetite, and eating behaviour.
• Delaying the introduction of complementary feeding until the age of 4 months may protect against later obesity and possibly against allergy and the development of coeliac disease, with little evidence that timing is influential beyond this age.
• A high protein intake during the complementary feeding period may be associated with an increased obesity risk.

Complementary feeding (CF) practices could potentially influence later health outcomes by a number of mechanisms including programming effects, but also by lasting effects on food preferences, appetite, and eating behaviour.

Traditional weaning practices such as feeding to comfort the infant and forced feeding, as well as our taste and flavour preferences, evolved to be suitable in conditions where food was scarce. They are not appropriate for modern obesogenic environments, and this may result in later problems such as distinguishing hunger from other distress cues, ignoring satiety signals, and preferring unsuitably sweet, energy-dense foods. However, although there is a clear genetic component to aspects of taste, flavour preferences, and appetite, parents and caregivers can modify environmental influences. For example, innate preferences for sweet flavours and dislike of bitter flavours can be modified by exposures during pregnancy and early infancy from breast milk but also from infant formulas; and these preferences can persist with continued exposure to a flavour [1, 2]. Parenting behaviour can also have positive effects on infant feeding practices and growth. A recent systematic review concluded that the most promising interventions for reducing the risk of overweight and obesity in infancy and early childhood are those that focus on diet and responsive feeding, including education on recognising infant hunger and satiety cues and non-food management of infant behaviour [3]. Twin studies suggest that some aspects of infant appetite are highly heritable, including eating speed and satiety [4], whilst appetite is probably causally related to weight gain [5]. This raises the intriguing possibility that it may be possible to identify individuals who are at risk of over-eating in an obesogenic environment and intervene to prevent adverse outcomes.

The evidence that ‘nutritional’ aspects of CF – the timing and content of foods – influence later health outcomes is limited in quantity and quality but suggests that delaying the introduction of CF until the age of 4 months may protect against later obesity [6] and possibly against allergy and the development of coeliac disease, with little evidence that timing is influential beyond this age [7–9]. Few studies have examined later outcomes in relation to specific nutrients or foods during the CF period, although there is concern that a high protein intake during this period could increase obesity risk [9].

CF practices vary markedly between and within countries. Given the complex interplay between nutrition, feeding behaviour, and psychological factors during this period, a holistic approach is required; a ‘one size fits all’ approach is not feasible or sensible given the variation between infants, their environments, and their cultural factors.

1. World Health Organization: Infant and young child nutrition. Geneva, WHO, 2003.
2. American Academy of Pediatrics: Breastfeeding and the use of human milk. Section on breastfeeding. Pediatrics 2012;129:e827– e841.
3. Denne SC: Neonatal nutrition. Pediatr Clin North Am 2015;62:427–438.
4. Destaillats F, Erdmann P, Thakkar SK, Lönnerdal B: A developmental perspective of the contents of total protein and bioactive proteins in breast milk. In preparation.
5. Kunz C, Lönnerdal B: Re-evaluation of the whey protein/casein ratio of human milk. Acta Paediatr 1992;81:107–112.
6. Lönnerdal B: Nutritional and physiologic significance of human milk proteins. Am J Clin Nutr 2003;77:1537S–1543S.
7. Lönnerdal B: Bioactive proteins in breast milk. J Paediatr Child Health 2013;49(suppl 1):1–7.