I grew up as a child who hovered between a normal weight and overweight. My parents didn't really comment on it, but it would have been useful to have had their help in dealing with it. They were loving and caring parents in most other ways.
Looking back, I can see in retrospect that the problem wasn't so much the weight, even at times when I was a bit podgy, but actually the lack of physical activity outside of school which led to poor fitness. We lived in a fairly isolated area where it was unsafe to play out, and playing out alone wasn't usual during our childhood anyway. You had to drive somewhere to do anything like bike-riding as there weren't any safe paths from our house. And our parents both worked full-time during the week and were exhausted by the weekend and so didn't really want to spend it doing active family activities.
What I needed was much less time being bored and much more in the way of accessible activities. My mother's food was fairly healthy, treats were sensible, but I just didn't get the chance to move enough as a child.
Realising this has probably manifested itself overly in my parenting, as although I'd never talk to my kids about weight (they're both under 11 anyway and I think that pre-secondary school/independence, it's entirely the parents' responsibility to quietly manage their children's weight and fitness), I do get antsy if they go even a day without doing at least another hour of physical activity on top of what they've done at school/nursery, and then something active both days of the weekend.
Maybe this is off on a tangent from the OP, but certainly before secondary school, my view is that parents should not mention weight but it's their job to provide the conditions for a healthy life. After secondary, when you can no longer control everything they eat, maybe it's useful to talk in generalized terms to kids about eating a healthy diet and doing enough exercise.