A friend of mine works for social services, she has one degree in sociology and one in psychology. She is married, and they have two sons (same age as my sons, so we do spend a lot of time together when we are in Norway)
Her youngest son saw the school nurse (In Norway children still see the school nurse for a health and developmental check twice during primary- each check up lasts around 45 minutes and covers mobility, healthy eating, pen grip, concerns, etc and later puberty), and was weighed, and my friend came out of the meeting in absolute shock that the nurse had said that she needed to start keeping an eye on her sons portion sizes, as was above average for weight.
She was not frothing for long though, and started paying attention to her sons eating. He would always go back for seconds at dinner/tea. He would always end up in the fridge looking for snacks soon after (Puddings are not part of a Norwegian diet, mostly people only eat pudding during the weekend, or for parties). He would make him self a nutella sandwich as a snack between dinner and evening meal. (In Norway people eat sandwich/cereals for breakfast, packed lunch for school, hot dinner, and sandwich/cereals/fruit before bed)
My friend decided the school nurse had a point, and she started restricting nutella to the weekends, and stopped having sweets/crisps in the house. She hesitated about the dinners, she felt she could not restrict his tea if he was still hungry after the first serving.
I should add, this boy plays football twice a week, and basket ball twice a week, in addition to being out playing football with his friends "down the road" at any waking moment. Skiing and mountain trips.
My friend is now actually quite glad the nurse gave her a wake up call as she herself had not noticed her son putting on weight. She never used to put her sons on the scales either, she figured they were happy and healthy and sporty. It allowed her to adjust things a little with regards to the balance of snacks and exercise.