Who needs to go on a diet?

Where do I start?
A friend recently recalled the story of a 4wd being pulled over in a roadside vehicle inspection.
It turns out he is on his way to work, so no "real" weight in the car other than the rooftop tent. Tanks are near empty ect ect.
Turns out he (the 4by) is "overweight". His pride and joy is now on a diet. But what to remove. This is all real important "stuff" he has in the 4by.
So this gets me thinking, "do need to loose some weight"?

Now i'll get to the point.
Just how many people have actually had the 4by weighed? Or is it better to drive on in ignorance?
When I check (roughly) not really a lot to work with 500-700kg depending on vehicle.
Some of the "must have" equipment listed on this site can not be light.

Thoughts please.

Regards

Wim