Toddler jumps 2 centiles but not fat - what could it be?

[Bucketsofdinosaurs]

Saw an HV in a different area today and mentioned my DS (19m) had gone suddenly from 50th to 91st centile at around 12m. She weighed him to confirm 91st centile and said she'd get my local HV to follow it up as apparently you're supposed to stay roughly the same centile as you were at 6wks old (he was 50th) . Think he's only about 50th for height but doesn't look odd, just surprises you when you pick him up.

He doesn't look fat, he practically has a 6pack and plays 'hard' when awake but sleeps twice a day plus through the night. He doesn't ask for food between meals or seem hungry (surely he'd be ill-tempered?) but definitely likes his food (not at all fussy.)
I wasn't worried before, just thought his appetite was unusual, but now I am although I don't know why I should be iyswim. What kind of health problem makes a weight gain without obesity? What could there be to worry about?

[zdl]

That's not right, about same centile at 6 weeks old stays for life. i know that for sure, which makes me doubt everything else (quite honestly).

If it were me I would ignore the centiles, ignore the HVs and look at child. Does he look a healthy size? Then he is. Closed case.

[louismummy]

often they put on weight then have a groth spurt so it all evens out, i wouldn't worry he sounds like my ds1. also ds now25months has hardly put any weight on for the last 6 months. don't worry.

[curlew]

If he doesn't llo fat and he feels nice and firm and chunky then solve the problem by not getting him weighed any more. Ooops, who said that?