Chunky toddler

My son had a pediatrician appointment today. His wellness check up. He is 3 days shy of being 16 months. He weighs 35 lbs. he just started walking on September 22. They had a talk with me about his weight. Which this is the first time they have ever brought it up tbh. He’s always been a real chunky boy his whole life. Even when he was born a bit weighed 8 lbs. Needless to say, they took him off whole milk and told us to give him 2% milk instead. It really threw me off because he’s been off the growth charts his entire life for weight. But, he eats decent food too. Most of it’s good for him tbh. Idk what I can do? Now that he’s walking I could take him out and be more active than we have been. We don’t necessarily do a ton of activities but we get out and do stuff if that makes sense.

Idk I was kinda offended because my son has had this quick weight gain forever now I wonder why they didn’t switch it up with the formula? He took the regular enfamil formula but like now I’m wondering if there’s like a low cal or some kind of formula. I kinda feel like a shit mom because I didn’t put this all together myself. Like ok he sat around for months on end before he started crawling but idk I feel like as he ages and grows taller he will level out. This has me feeling a type of way tbh.

Update

Thank you all. I feel much better because this isn’t sudden weight gain and I just know some of his extra baby weight will come off soon. Just takes time.