Failure to thrive

By Dr Megan Yap - PaediatricianGeneral20 Nov 2017

The term “Failure to Thrive” is enough to strike fear in a parent or carer’s heart… Or at least it does in mine (but then, I’m an Asian mum and I’m a feeder!!)

Initially for many mums, it feels like the weight of the expectation of breastfeeding your baby your “home-made liquid gold” when it is born, might crush your very skull and all of its contents… and then later it seriously feels like your entire BEING is devoted to shoveling home-made delicious (hence palatable and desirable), nutrition packed but low sugar, and of course natural, preferably organic, with no preservatives or artificial colourings, more recently also dairy, gluten and nut free food, into your child’s mouth to help them to grow and be the incredible human you just know they are destined to be.

And then they need to gain weight.  Not too much though… but also not too little.  Just enough.

Seems easy enough.  Right?  NOT.

And then you get a child who vomits/has reflux/has a chronic medical condition/has coeliac disease/won’t eat/spits everything out/refuses to touch your “perfect” home made food….

AAARGH!!!!!  Seriously, if you are one of those lucky people who just have kids that eat anything and just grow – go you good thing!  I am totes jelly (ie totally jealous).

Both my kids were pukers (one of them is still a “protest puker” – but perhaps we might go into that another day when I am talking about “managing bad behaviour”), one of the them thrived and was practically obese (in retrospect, she was really grumpy and I think I overfed her thinking she was hungry, but actually she prolly just had reflux) and the other was born prem, and although born absolutely average weight (for his gestation), dropped at about 2 months old (corrected age) to below the 5th percentile and freaked the hell out of me.  He is still super skinny.  He LIKES food (I think… well, he’s always asking for it and pointing to it) but he also likes to chew his food up, and then gently takes your hand (like as if to thank you for your labour of love prepping the food) only to spit it all out in your palm.

There is SO MUCH MORE to poor weight gain than just “not enough food/calories” though, so I hoped that this post might shed a bit of light on that, and why doctors seem to get so worked up about something that might seem pretty common.  Kids usually just gain weight over time.  Sometimes they lose a bit of weight, and this can be normal (or at least expected), especially if they are unwell for a period of time.  However, if this goes on for a LONGER time, it can impact on a child’s development, and then your child might not go on to win that Nobel Prize you know they are on a trajectory for….  ha ha… no seriously.  IF poor weight gain goes on, it will later affect height, then head circumference.  The child might seem to lose interest in the world around them, and in engaging with people, and not reach their developmental milestones, become fussy eaters and unhappy and irritable.

So… what can cause it?


A number of things can cause failure to thrive, including:

  • Not enough food offered. In some cases, parents mistakenly cause the problem. Sometimes a parent measures formula incorrectly, causing an infant to get too few calories. Problems with breastfeeding or transitioning to solids also can cause failure to thrive. Parents who worry their child will get fat may restrict the amount of calories they give their infants. And sometimes parents don’t pay enough attention to their children’s hunger cues or can’t afford enough food for their children.
  • The child eats too little. Some children have trouble eating enough food because of prematurity, developmental delays, or conditions like autism in which they do not like eating foods of certain textures or tastes.
  • Health problems involving the digestive system. Several health conditions can prevent a child from gaining weight. These include reflux, chronic diarrhoea, cystic fibrosis, chronic liver disease, and coeliac disease.With reflux, the oesophagus may become so irritated that a child refuses to eat because it hurts. Persistent diarrhoea can make it hard for the body to hold on to the nutrients and calories from food. Cystic fibrosis, chronic liver disease, and coeliac disease all cause problems with the body’s ability to absorb nutrients. The child may eat a lot, but the body doesn’t absorb and retain enough of that food. Kids with coeliac disease are allergic to gluten, a protein found in wheat and other grains. The immune system’s abnormal response to this protein damages the lining of the intestine so it can’t absorb nutrients properly.
  • Food intolerance. A food intolerance which is different from a food allergy, means the body is sensitive to certain foods. For example, milk protein intolerance means the body can’t absorb foods that have milk proteins, such as yogurt and cheese, which could lead to failure to thrive.
  • An ongoing illness or disorder. A child who has trouble eating — because of prematurity or a cleft lip or palate, for example — may not take in enough calories to support normal growth. Other conditions involving the heart, lungs, or endocrine system (the glands in the body and the hormones they produce) can increase the amount of calories a child needs and make it hard for the child to eat enough to keep up (eg diabetes, cystic fibrosis, hyperthyroidism).
  • Infections. Parasites, urinary tract infections, and other infections can force the body to use nutrients rapidly and decrease appetite. This can lead to short- or long-term failure to thrive.
  • Metabolic disorders. Metabolic disorders are health conditions that make it hard for the body to break down, process, or take energy from food. They also can cause a child to eat poorly or vomit.

Sometimes a mix of medical problems and environmental factors leads to failure to thrive. For instance, if a baby has severe reflux and is reluctant to eat (because it results in pain), feeding times can be stressful. The baby may become upset and frustrated, and the caregiver might be unable to feed the child enough food.

Other times, we can’t figure out exactly what causes the problem



Many babies go through brief periods when their weight gain levels out, or they even lose a little weight (especially in the context of illness). This is not unusual. However, if a baby doesn’t gain weight for some time, OR they only gain a small amount and start to cross downwards through the percentiles, during the first year of life, I would usually become concerned.

Doctors use standard growth charts to plot weight, length, and head circumference, which are measured at the time of the medical consultation.  I like the APEG charts, but I think the WHO standard growth charts are recommended.  Children who have certain conditions or syndromes, may need to use charts specific to their condition as their rate of growth may be different as a result of that condition (eg Down Syndrome). Children may have failure to thrive if they fall below a certain weight range for their age or fail to gain weight at the expected rate.

To see if there’s a problem, doctors will take a child’s detailed health history, including a feeding history. This helps doctors see whether underfeeding, household stresses, or feeding problems might be to blame. A referral might be made to a paediatric dietician to track the calories in a child’s diet to make sure the child is getting enough.

Investigations might be ordered also to find out if there is an underlying medical reason why the child cannot gain weight.  These might include blood tests, urine tests and poo tests.  These tests are to look for all the different conditions that are listed in the “Causes” section above.


How much weight should my baby/child be gaining?  I stole the below chart from the RCH Melbourne parent sheet on “Poor Growth”


The rate of weight gain per week is variable.  Babies less than 3 months old might be weighed weekly (generally younger kids need to be seen more frequently).

The table below is a guide to the expected average weight gain per week (it is not the minimally acceptable weight gain).

0 to 3 months 150 -200g/week
3 to 6 months 100 – 150g/week
6 to 12 months 70-90g/week


So if my kid is NOT gaining weight, WHAT CAN I DO ABOUT IT???

Hate to tell you this guys, but if your kid is not gaining weight or is LOSING weight, you really need to go and see your doctor.  Medical causes need to be ruled out.

BUT if they have all been ruled out OR you have a kid that is still in the normal range but a little on the chicken-leg side of things, essentially you need to ADD CALORIES to their diet.

How do we do this?  There are heaps of different ways.

Choose high energy foods that are also high in nutrition.  We don’t worry about “bad cholesterol” in kids really under the age of 5, so if your kid likes sausages – GIVE them sausages!

Some examples might be:

  • Instead of choosing a rice cracker for morning tea, choose a cracker with an avocado slice on it or a piece of cheese
  • Nuts are a good snack, that are high in protein and in good fats (just be careful for school/kindy snacks as some places are nut free because of the allergy risk for some kids)
  • Try a boiled egg (or two) or an omelette for brekkie on toast (as opposed to say, Vegemite) OR as a snack for morning or afternoon tea
  • Make sure they have FULL-FAT everything (eg yoghurt, milk, cheese etc).
  • Always butter their bread, crackers, sandwiches
  • Add Milo to their full cream milk
  • Add a tablespoon of olive oil to their meals (eg to spaghetti bolognaise, or into your mince when making meatballs, drizzled over pizzas, to rice and stir fries etc)
  • Add CREAM to their meals (eg any kind of pasta, stir-fries, soups)

Calories can also be added to their diet by protein shakes/vitamin enriched energy supplement preparations that you can buy at the chemist or directly from the companies that produce them.

  • Sustagen is available in 800g tins or in ready made poppers in various flavours (and there are specially formulated kids versions)
  • Pediasure is also available in tins, sachets or in ready made drinks/poppers in chocolate, strawberry and vanilla flavours (I think there might be a banana one too). From experience, most kids find these palatable.  I usually start with giving them 1-2 of these on top of their usual diet each day.
  • Ensure is another one  (though I am not sure if they make a kids version of this)

Seeing a paediatric dietician/nutritionist can be a really valuable exercise as an experienced one will have lots of tips and tricks up their sleeve to help you.  For kids with feeding difficulties, a referral off to a feeding clinic (ask you GP or paediatrician – there are usually feeding clinics at most hospitals that see children, at some local community health centres and even some run privately) – where there will more than likely be a multidisciplinary approach (eg dietician, speech pathologist, occupational therapist) to helping your child with feeding issues.


As a mum to a fussy eater/poor weight gainer myself – I totally understand how frustrating this problem is and all I can say is, “Don’t give up! Keep trying!”  and definitely seek help (there is a lot of it out there) if you need it.  I tend to worry very little about “overweight” babies (within reason of course), as I know they need reserve, especially if they get sick and intake slows or stops for a few days.  But that is another story.


Until next time, stay well!!!!!!!!!!!!!!!!!!!!!!!!!!!

xxDr Megs

For more articles from Dr Megan Yap visit her blog – “Dr Megs – Paeds & Feeds” at


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