This is more or less what I was going to say. Age 2 is also typically when they start using the pushchair less and start walking more, their coordination increases, their motor skills become more refined, and they become way more active which is when they really start to lean out.
HV at my eldest's 2yr check told me she was concerned about DC being on 95th centile. I pointed out DC had always been on that line even when a newborn, didn't eat junk or massive portions, and was very active (something which she also commented on when she asked "do they ever sit still!?"). It worried me so I saw my GP. GP laughed and said DC was fine, that HVs create more worry than they resolve, and that they'd only be concerned if DC's reception age weight and height check came back as over/underweight. Reception height and weight check came back as normal, DC now taller than me and not at all "chunky."
DC2 was the polar opposite and on 5th centile which also caused questions at the 2yr check. HV asked me to keep a food diary as was concerned DC wasn't eating enough. Was stunned a week later at how much DC was putting away and gave me some patronising advice about "too much of a good thing" and to let DC have some treats because they "have centiles to spare." DC is also now taller than me, calls me "bruh" as is "bruh, I'm starving", and is still a human hoover who never seems to put on weight.
DC3, 50th centile for height and weight despite eating nothing. At age 2 was living on Babybels, plain chicken breast, bananas, and uncooked yellow peppers. They wouldn't refer me to a dietician because they were "all healthy foods" and DC was "a healthy weight." Later diagnosed with ASD and ARFID.
DC4 was another one who was 95th centile from birth. HV quizzed me about DC's food to see where I could cut down. She agreed you can't really cut down on half a dry Weetabix at breakfast, one scrambled egg at lunch, and chicken and cucumber at dinner. She looked at me like I was lying when I said DC didn't like sweets and that their favourite snack was a bowl of garden peas, preferably still frozen. DC also later diagnosed with ASD and ARFID.