All sims 4 sims having fat babies! (When aged up to toddlers)

All the sims in my game are having fat babies! Every single baby/toddler that my sims have had in any family are fat in all saves and games.  I know this may not seem like such a big deal, but everyone in town being fat is getting really frustrating.  

I have tried changing the mom's diet during pregnancy and only eating healthy stuff, no difference. 
I tested if it was genetics and made the skinniest couple and had them have a baby and it ended up fat as well.

Any ideas if this a glitch or how I can prevent the babies/toddlers from being fat right from the start? 

(Sims 4 all expansions including laundry day, game is up-to-date with no CC or mods).