It is - all other things being equal Asians tend to develop diabetes and cardiovascular problems at lower weights than other ethnicities. For perspective the Japanese health ministry has set the cutoffs for overweight and obesity at 23 and 27 kg/m2 compared to 25 and 30 in the US. For a 5'8" man (the average height of a Japanese man according to
Wokepedia) that works out to the cutoff for a healthy weight being 12 pounds lower and the cutoff for obesity being 18 pounds lower.
Edit to Add: The lower BMI cutoffs for overweight/obesity do not result in lower cutoffs for underweight, Japan uses the same value (18.5 kg/m2) as the rest of the world. Maybe there's good science behind it, maybe it's just taken from the US for convenience, I'm not sure. Good luck commissioning a study on this nowadays.
This is anecdotal but most Asians I've met have also had a naturally lean build - even if they're in the healthy BMI range or slightly over, they just don't carry weight well.
Edit x2:
Probably culture IMO - at least in the US Asian parents, even ones who are 3rd generation or beyond, tend to be extremely demanding and unforgiving. If little Timmy starts looking a little pudgy that's not something he'll grow into, it's something that needs. to. be. dealt. with. right. fucking. now.