MIL every now and then frets that our kids don't do enough sports and often buys them things that will encourage them to be more active in a heavily Dropping A Hint Manner - she's a bit of fatphobe and I think is convinced our kids will become overweight and unhealthy if they're not doing sporty stuff (other grandkids are very sporty). Kids (11 and 14) are not overweight, nor unhealthy as far as I can tell, DS in particular is a skinny little stick.
I grew up in a household where we all stopped doing sports as soon as GCSEs were over, none of us was ever in a sports team or did any extra-curricular sports and my sister was the only one of us to ride a bike (and that was only about for a year or two) and none of was or is overweight. But we ate a decent diet and were not ferried everywhere by car - neither are my kids and they both walk 1.5 miles each way to and from school every weekday, so it's not like they're totally sedentary. Anyone else had to deal with someone who thinks kids have to be doing sport to be healthy?