Talking through BMI centiles with parents

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It can be a difficult thing to tell a parent/carer that their child is over- or under-weight (see communicating with parents about weight module). If parents/carers are unaware there is an issue, the news could come as a shock and might cause initial upset or anger. Yet this is sometimes a necessary process for parents/carers to go through to recognise the need to change. 

The following guidance is provided to support you in presenting information about the child’s weight in an informative, yet sensitive, manner. This approach was developed through the GOALS child weight management programme in Liverpool with parents/carers often commenting it was the first time someone had explained to them in “black and white” about their child’s weight.

Faq Items

Avoid sugar-coating information

Whilst it might seem best to to “play the issue down” or avoid the term “obese”, this can sometimes make things worse. Being told the facts about their child’s weight can be an important step to help families move forward.      

Being direct doesn't mean being insensitive

You will see in the videos below that it is possible to share difficult weight-related information in a sensitive manner. The following hints may help: 

a) Tone of voice and body language:  By adopting a non-judgemental tone and open body language, you will help parents/carers feel more at ease.    

b) How the information is presented:  Parents/carers need to be given time to digest the facts before any emotional response kicks in. One way this can be achieved is by first explaining BMI and how under/over-weight is identified in a clear, factual manner (before mentioning their individual child).  Once this is done and understood, you then explain where their child fits within this (e.g. by showing where they are on the BMI chart).  

c)  Presenting weight as a changeable component rather than a trait of the child: In video 2 below you will see the practitioner uses the word obese, but she does not specifically say the words “Chloe is obese”. Instead she talks the father through the BMI chart before showing him where Chloe is on the chart. The father is then able to work out for himself what Chloe’s weight status is. If you do feel the need to explain, it may be better to say “Chloe’s BMI is within the obese category” than “Chloe is obese”, since the first example separates Chloe’s weight from who she is as a person, rather than defining Chloe by her weight. This can be encouraging to help her father see weight as a manageable and changeable factor.        

d) Allowing time: You will see in the videos the practitioner talks through the information at a gentle pace and allows pauses throughout the consultation for the parent to digest the information. She also offers parents a chance to ask any questions and helps them feel ok to do so. Silence can feel uncomfortable, but it can also be helpful in allowing time to work through things. It is important to try and resist the temptation to fill any silences with “sugar-coated” information to help the parent feel better.    

e) Be empathic: Try and imagine how it feels for the parent/carer to receive this information. If they get upset or express surprise, let them know it is normal to feel this way. Acknowledge that it can be difficult for parents/carers to identify whether their child’s weight is healthy (which may help reduce any feelings of guilt they are experiencing). Give them space to work through their emotions and to ask any questions they may have.

The two videos below provide examples of talking through children’s weight, height and BMI with parents. Parents in the videos are actors and children’s names are fictional.  

In video 1, Paula is talking to the mother of a 3-year old boy (Toby), who is worried he is underweight. In this video Paula uses the UK Growth Chart Boys 2-18 years to explain Toby’s height, weight and how this converts to BMI.


In video 2, Paula is talking to the father of a 4-year old girl (Chloe).  Paula uses the UK Growth Chart Girls 2-18 years to explain Chloe’s height and weight, but moves straight to the BMI chart for children aged 2-20 years to explain Chloe’s BMI (because Chloe has overweight, both visually and from the fact her weight centile is a lot higher than her height centile).  


Tracking BMI over time for children with over-weight

As children are still growing, they will reduce their BMI centile by stabilising their weight, or even by putting on weight at a slower rate than they gain height. The recommended approach to achieve this is through lifestyle changes to physical activity and diet, as discussed in the Infant and Child Nutrition and Physical Activity and Sedentary Behaviour modules. Therefore when following-up with children, you should be encouraged by any reduction in BMI centile, as it will take time for children who are very overweight to achieve a healthy BMI.  

Figure 2 and figure 3 show how it would look on the charts if Chloe (video 2) were to maintain her weight while she continues to grow along the height centiles. Figure 2 shows the height and weight chart, and figure 3 shows the BMI chart.  It can be seen that over a period of 18 months Chloe’s weight drops from > 98th centile to between the 75th and 91st centile. This brings her BMI down from 20.9kg/m2 to 17.1kg/m2, and her BMI centile from >99.6th centile (severely obese) to < 91st centile (healthy). 


Below is a short quiz to help you evaluate your learning from this module. You may take the quiz as many times as you like.