The Best age to start solids

The best age to start solids is a controversial subject and official advice has changed over the decades. However, we know more about baby health and nutrition than ever before, and based on the current scientific evidence, “around six months” or “about six months” is now widely recommended as the ideal age (the Australian government, the UK Department of Health, the American Academy of Pediatrics and the New Zealand Ministry of Health all recommend this age).

What does “around six months” mean exactly? National guidelines do not typically provide a precise definition for this term. However, one exception to this is the current draft Australian infant feeding guidelines, which state that “around six months” means between 22 and 26 weeks (which equates to five to six months).

The World Health Organization actually recommends exclusive breastfeeding (that is, no solid foods) for a full six months. This timing is important in developing countries, where access to healthy foods can be limited, sterile, nutritious breastmilk is often the safest feeding option. However, in many developed countries, where fresh healthy produce is usually widely available, this recommendation is relaxed, with official government advice typically stating that infants should start solid foods at “around” six months instead.

There are good reasons to follow the recommendation to wait until around six months before introducing solid foods to your baby. Starting too early can cause problems because:

• Breastmilk is the ultimate baby food, providing the best possible nutrition for a baby. If solids are introduced too early, a baby may miss out on that precious breastmilk and his mum’s milk supply may drop.

• Babies have immature digestive systems that simply can’t cope with solid foods in the early months. Older babies, like adults, produce pancreatic enzymes that help them to digest food. However, these are virtually absent until three months and inadequate until around six months.

• Young babies have a strong tongue-extrusion reflex that prompts them to push out any hard objects put into their mouths, such as a spoon. In young infants, this can make spoon-feeding difficult for parents, potentially creating a stressful, pressured feeding environment for everyone. This reflex starts to fade around four months, although the timing varies among babies.

• Exposure to potentially unsafe microorganisms in foods can place a baby at an increased risk of diarrhoea and other health problems.

• Babies are born with immature kidneys, which develop during their first year. Solid foods, particularly those that have a high protein content or added salt, put added pressure on a baby’s kidneys (which is particularly problematic when a baby is ill or unable to drink enough fluids). As a baby gets older, his developing kidneys are better able to cope with the waste products derived from solid foods.

• Younger babies take longer to adjust to eating solid food. A Swedish study found that babies aged under four months took an average of 42 days to eat more than two teaspoons of solid food daily, while babies six months and older took an average of just 12 days – over three times faster than their younger peers.

Introducing solid foods much later than six months is also problematic. Here’s why:

• At around six months, it becomes increasingly difficult to meet a baby’s nutrient requirements from milk alone. A baby’s growth may be affected if solid foods are not introduced around this time.

• In particular, iron and zinc stores, which build up during pregnancy, become depleted at around six months, and need to be restored through iron-rich foods, such as meats and iron-fortified cereals. Having a milk-only diet beyond six months puts a baby at risk of iron and zinc deficiency.

• There is some evidence that delaying the introduction of solids may increase the risk of food allergy. Further scientific research is currently being done to determine whether or not this is true.

• The optimal development of motor skills, like chewing, can be affected if solid foods are delayed for too long.

[This post is adapted from an extract from my book Cooking For Your Baby and Toddler]