Solids

There seem to be two recommendations of when to start solids:

1. start your baby between 4-6 months when they show interest and willingness in taking food off a spoon; and
2. do not start your baby on solids before 6 months.

Needless to say, you can't follow both these recommendations.  So why does the advice conflict and which is correct?

The short answer:

As far as I can work out, the answer is that if you live in a developed country and practice appropriate hygiene in the preparation of food, the risks in introducing solids after 4 months are negligible.  There is nothing wrong with exclusive breastfeeding until 6 months either - and if you are breastfeeding, continuing to breastfeed through the period you are introducing solids is highly recommended.  Even after you introduce solids, most of your baby's nutritional needs will be met by breast milk or formula until at least 12 months of age.

Personally, I reckon that now my baby is at an age where she is putting everything in her mouth and gumming the floor, the risk of her picking up extra bugs from hygienically prepared solids is minimal.

Here's the evidence:

It was previously thought that exclusive breastfeeding until 6 months and delaying the introduction of allergenic foods such as eggs could reduce the development of allergies in children.  The current state of the research is that there is no clear evidence that delaying solids until 6 months makes the development of allergies more or less likely.  The Australasian Society of Clinical Immunology and Allergy (ASCIA) summarises its position based on research into allergies as follows:

Do not:

• introduce solids before 4 months

What can help prevent allergies: 

• breastfeeding up to and during the period of introduction of solid foods
• if breastfeeding is not possible, there is some evidence that hydrolysed formula can help prevent allergies (fully hydrolysed formula is only available by prescription - partially hydrolysed formula is sold as HA formula) 

What probably makes no difference: 

• excluding foods from the breastfeeding mother's diet

• delaying the introduction of solid foods for longer than six months 

• delaying introducing potentially allergenic foods such as egg, nuts, wheat, cow's milk and fish - if the child's going to develop an allergy, they will probably develop it anyway

The tricky part is that the ASCIA also states:

• "more research is needed to determine the optimal time to start complementary solid foods.  Based on the currently available evidence, many experts across Europe, Australia and North America recommend introducing complementary solid foods from around 4-6 months."
• "There have been some suggestions that delaying the introduction of foods may actually increase (rather than decrease) allergy, however at this stage this is not proven." 

This part of the advice is a bit vague for me.  Which experts?  Why do they say 4-6 months is optimal?  And what is meant by 'delaying the introduction of foods'?  Till 4 months?  6 months?  A year?

And no wonder it is vague, when joint position paper of the European and North American Societies for Paediatric, Gastroenterology, Hepatology and Nutrition actually says:

"Exclusive or full breast-feeding for about 6 months is a desirable goal. Complementary feeding (ie, solid foods and liquids other than breast milk or infant formula and follow-on formula) should not be introduced before 17 weeks and not later than 26 weeks."

A quick bit of maths reveals that this advice tells you to exclusively breastfeed (no solids) for 6 months, but to introduce solids before 6 months.  Nice.  In one breath, two major leading health organisations give you a recommendation that is basically impossible to follow.

The reason solids are not introduced before 17 weeks is due to the infant gut not being mature, leading to risks of allergies, infections etc, as well as failure to thrive issues from the infant taking less milk.  As to what time after this is appropriate:

"With respect to neurodevelopment, it is likely that, as with any motor skill, there will be a range of ages in infant populations for the attainment of most milestones. For example, by around 6 months, most infants can sit with support and can ‘‘sweep a spoon’’ with their upper lip, rather than merely suck semisolid food off the spoon. By around 8 months they have developed sufficient tongue flexibility to enable them to chew and swallow more solid lumpier foods in larger portions. From 9 to 12 months, most infants have the manual skills to feed themselves, drink from a standard cup using both hands, and eat food prepared for the rest of the family, with only minor adaptations (cut into bite-sized portions and eaten from a spoon, or as finger foods). An important consideration is that there may be a critical window for introducing lumpy solid foods, and if these are not introduced by around 10 months of age, it may increase the risk of feeding difficulties later on (15). It is therefore important for both developmental and nutritional reasons to give age-appropriate foods of the correct consistency and by the correct method.

The Committee considers that gastrointestinal and renal functions are sufficiently mature by around 4 months of age to enable term infants to process some complementary foods, and that there is a range of ages at which infants attain the necessary motor skills to cope safely with complementary feedings." (taken from the joint position paper cited above)

A look at the detail of the paper reveals no clear reason why there is such a strong recommendation to introduce solids before 26 weeks.  There are some studies that suggest iron deficiency can occur if babies are exclusively breastfed to 6 months, but this probably depends on the amount of iron the baby obtained in utero, which in turn depends on the mother's diet and whether the baby was full term (premmie babies may not have enough iron in their bodies).  The 2002 World Health Organisation (WHO) report on the Nutrient adequacy of exclusive breastfeeding for the term infant during the first six months of life found that breast milk did not provide all the infant iron needs, but for the first six months the infant drew on iron reserves already in his or her body.  After 6 months, complementary feeding was necessary to ensure adequate iron.

The Australian National Health and Medical Research Council states that:

"A number of observational studies and two randomised trials have not identified any benefits from the introduction of solid foods before the age of 6 months."

But when you actually look at the studies they are referring to, both were conducted in the developing Honduras.  It is therefore unclear how applicable these studies are to developed countries like Australia.

The World Health Organisation (WHO) is best associated with the position that babies should be breastfed exclusively until 6 months of age.  But when I looked at the evidence provided by the WHO website, particularly the 2001 The Optimal Duration of Exclusive Breastfeeding: A Systematic Review, the evidence really only supports delaying solids in developing countries or in households with other risk factors - such as smoking, low socio-economic status etc.  There may be a small elevated risk of gastrointestinal infection when starting solids early (as evidenced from a large study in Belarus, but not demonstrated in a smaller Australian study), but such infections are extremely unlikely to result in infant deaths in a developed country.  What the review set out to establish and could basically support was that there was no harm in exclusive breastfeeding for at least 6 months.

When the evidence is this way, why is exclusive breastfeeding until 6 months advocated so strongly in developed countries?  In part, this may be a public policy decision (see the ANHMRC paper p47)  - as it is feared that when parents are given the 4-6 month range, mothers who feel their babies are advanced try to introduce solids before 4 months (17 weeks) where statistically most babies' guts are not ready, and there are higher risks.

Methods for starting solids:


There are two basic methods for starting solids - using purees and spoon feeding, or starting later with finger-foods using 'baby led weaning'.

Purees and spoon feeding allow you to start feeding your baby solids before they can sit up and before they develop the motor skills to do anything other than suck on objects placed in their mouth.  Harder food is a choking hazard for babies without these skills, which typically develop around 6 months, although the age can vary greatly from baby to baby.  For information on how to do this method, including recipes etc, you can find advice on Annabel Karmel's homepage.

Baby led weaning involves waiting until the baby is older and then essentially starting them straight on finger foods.  BLW advocates like that this means less work than a long period of pureeing food etc (although this may be more true for breastfeeding mums than mums doing formula).  Other possible benefits is that the baby learns that food is for chewing not sucking from the outset, so potentially less risk of choking, and that babies develop a positive relationship with food by feeding themselves the quantities they need, not being force-fed.  For more information on how to do this method, see advice from Gill Rapley or for more detailed information this blog.