@user1468863258
I can see so many odd things in your posts.
First, there are some flights back to the UK.
It's not clear if you have tried to get one or don't want one.
As others have asked, why are your companies (if you are employees) expecting you to do 'shift work' by working from different time zones?
Is this practical with a young family?
Secondly, you don't appear to be very assertive.
I'd not consider you as 'guests' when you are with in laws- they are family, surely?
If you and your husband cannot speak clearly to them and ask what snacks they have fed your child, that's your fault- no one else's.
It sounds a bit pathetic to be honest to say you cannot ask them directly for fear of offending them when your child has a health issue and they are making it worse.
When you come back to the UK- or even before, using online services - I'd suggest you enrol in some form of parenting course. This will help you create boundaries and take back control. At present, your son is controlling you and his grandparents. he does this through asking for food. Somewhere along the line he has learned that asking for food gets him attention, that you are emotionally invested in hos food and if only he cries enough and makes a fuss, someone will give in to him.
He cannot possibly understand 'feeling full' or anything about healthy eating.
Your son has behavioural issues- not simply food issues.
The food is a symptom but his behaviour is all about getting attention and pushing your buttons. It's the reverse of a fussy eater.
You really need help from a child psychologist who can help you parent in a way to help you and him.
If he has always been overweight on the 99th percentile, but his height is on the 10th percentile, how do you account for that?
As his mum, you are the one who buys, cooks and feeds him.
I'd be really interested to know what he eats in a day.
Over the years there have been numerous thread on here about food and quantities.
It's shocking at times to see parents who think their child eats a normal portion when in fact it was an adult portion.
You may have skewed ideas of what a portion size is.
Any / most food will increase weight if enough of it eaten so saying you have 'healthy food' is not always accurate.
What I see from your latest post is that your son creates and demands food. He is NOT hungry. He is using this behaviour for attention. He may decide to call his 'needs' hunger but they are probably not.
At some stage you and your DH decided to pacify him by giving in to his wants, and the pattern was established.
Please see this as a behavioural and parenting issue, not a food issue.
You need to change whatever you are doing so he will change.
Put yourself in charge and start telling your in laws what's what for a start.
BUT your heart has to be in it. what comes over is that you can't bear to see him upset so you give in and let him take control of you all.