No I don't. For me, it comes from my own childhood where we were forced to eat every scrap on our plates (not physically forced, but not allowed to leave the dining room until the plate was empty - how ever long that may take). I totally understand why they did it - money was tight & they couldn't bear to see money being wasted.
Whilst I don't blame my parents at all for my obesity as an adult, I do definitely think that the idea of "everything must be eaten" has become so ingrained in me from childhood that it has clearly become a contributing factor throughout life.
I also feel that taking the "your plate must be cleared to have a pudding" stance, places emphasis on the sweet pudding being the 'treat' element of the meal. The prize for enduring a mammoth plateful of fish pie & cabbage. As an adult, I have always used sweet foods as treats - even though, bizarrely, I prefer the taste of savoury food - which has meant that every time I think I deserve a 'treat' (bad day, good day, boring day, upset etc. etc.) I turn to cake, chocolate, ice cream etc. I put this down to having been taught that these things were ultimate treats as a child.
We don't have pudding as such in our house (unless we are eating out & then the DCs will choose whether or not they want one). We will have dinner & then people will ask for something else later if they are still hungry. This is just as likely to be a bowl of cereal as a bowl of ice-cream though.