@BarbaraofSeville
“Lack of money is rarely the primary reason why children are overweight. After all it costs a lot more to buy fast food, sweets, sugary drinks, crisps etc.”
Your right fruit, veg, making from scratch can be cheeper. But you can buy cheap white bread from Aldi for 50p, tub of chocolate spread for 89p, and a 24 multipack of crisps For about 1.99, pack of 5 chocolate bars for 50p maybe. That’s probably going to last longer than 6 tiny apples for 89p, a block of cheese/pack of ham that’s 1.99 and some better quality bread that’s £1. Stuff like crisps, chocolate, pizza, hot dogs are all more filling. It’s cheaper to buy 6 burgers than it is to buy a pack of chicken breasts, you can buy a bag of chips that might last a week for 89p.
You can eat well with limited funds, but it’s hard, and not everyone can cook, not everyone has a big enough freezer to store plenty of frozen stuff.
In relation to the original OP I do think weighing children even yearly should be something done so you can check their weight to see big jumps/decreases. A little like they do with babies. I think a lifetime of obesity and weight related issues is more damaging to a child/adult than them being asked to stand on a scale once a year. It needs to be done properly, and not infront of everyone and the school needs to work with the parents to help them make the changes if needs be. How many time’s do you see posts of weight loss on this forum saying that they are overweight as an adult and they were overweight as a child, that mum and dad made bad food choices and they are unable to break that habit that developed in childhood.