Juice and Junk Food

I'm a huge believer in people raising their kids their own way, but I've recently found out that my SIL's kids basically only eat junk food and that is terrifying to me.

We didn't visit each other for quite a while due to restrictions, but I managed to spend a whole day there last week. During that day, I watched as SIL's oldest (5 years old) finished one full bottle of orange juice (1L, split throughout the day) while eating an Aero bar, half a KitKat bar and - for dinner - a slice of cake from FILs birthday. Her 4 year old drank half a bottle of lemonade (approximately 500mL), at least 10 Ferrero Roche chocolates, three tablespoons of cupcake sprinkles (minus the cupcakes...and I know the measurement because SIL asked me to serve her kid and...I cringed) and a slice of the same cake. They didn't eat anything else the whole time I was there (unless maybe they had more chocolates while I was distracted), and MIL said this was how they normally "snacked".

My kids were with me and the oldest (5 years old) had a slice of the cake after dinner (Mexican) but we don't allow processed juices unless we have no options or they are sick (apple juice for electrolytes per their pediatrician), and chocolates are a rare treat. My other kids wanted savoury foods that day (MIL is a fantastic cook) and didn't end up having any desserts.

MIL and SIL think we are too strict with our kid's diets, and that SIL's kids will outgrow their sweet tooths ("They're kids, let them enjoy life now!"). My husband doesn't like telling them that we do sometimes treat our kids because he thinks it will make MIL and SIL think it's okay to feed our kids junk. (They tried to give the kids a bag of Kinder Surprise to take home.)

So yeah...this was just a rant to say that I'm scared for those kid's healths and annoyed that we are being pressured to join the unhealthy (sugar) bandwagon.

EDIT:

- MIL and SIL both acknowledged that the kids eat like this every day, but they believe they will outgrow it. (Both kids are very skinny and active, so the adults won't accept there is a risk of diabetes, obesity and/or eating disorders.) At one point my husband was talking about breakfast ideas and SIL said "If they won't finish their cereal, I give them chocolate before school to avoid arguing." (That was the day my husband decided that our kids will never visit them without us. 😅)

- Yes, I basically did see what they ate all day because I spent most of the day in the living room (where the chocolate tray was) and the room is open-concept and opened into the kitchen. I couldn't have avoided seeing it if I wanted, plus I WAS keeping an eye out to see what my kids were doing and eating.

- Like I said in my original post, I don't interfere with other people's parenting, but it is infuriating when they try to make it seem like we are horrible for limiting our kid's junk intake. They've actually said to me "What are you going to do without teaching them to eat sugar?" I replied "Kids will easily eat sugar...it's not something you need to force feed." 😐

And our kids are more likely to ask for fruits over chocolate, fresh smoothies over store-bought juices and savoury over sweet. They do get treats (chocolates, juices, pizza, etc.) but not every day and not an unlimited supply. This might change when they're older and are able to access more junk on their own, but I figured we would get the foundation right and they can make their own choices as they get older.

EDIT #2:

- Their household income is high (they even have hired help) so money isn't an issue.

- SIL is very health oriented herself - she always eats well, mostly buys organic, works out, etc.