Height/weight/BMI - I'm confused

[ManicMother7777]

DS is 10 and has always been big for his age always on a high centile (i.e 90+) for weight and height. In the early years, what seemed to matter to HVs is that height and weight centile were the same.

For the last few years he's remained on 91st centile for weight and height. However according to this website www.nhs.uk/Tools/Pages/Healthyweightcalculator.aspx he is overweight, verging on obese.

I can't understand why 91st centile has always been fine but is now overweight. I could understand it if his weight was 91st and height was lower, but they are the same.

Any pearls of wisdom, MNetters?

The school nurse explained to me that they - whoever they may be - are in the process of changing the old style centile books and re-working them. The old books were apparently taken on averages for predominantly white and high mix of bottle fed children. Nowadays it seems that if you add ethnicity and breastfeeding more accurately into the % mix, you get different banding, particularly for weight.
But i'm with you with the larger children. I have 3DS. The shortest is 91st - the tallest off the chart. I have a 98 centile DS who is only 50 centile for weight who i think should chunk up a bit, but apparently he is a good healthy weight so no problems there. To be honest, as a mum, you know if they are there or there abouts with their weight - i wouldn't get too worried about another system for checking their weight, go by your instincts.

Thanks aunt, agree about instincts.