Should junk food be banned in the UK?

No. It teaches bad habits to children too so why say only adults? If you are going to ban it from kids you best ban adults from it! Truth is there are more obese kids than healthy. More obese adults then healthy. I think your idea is coming close to an answer but not quite there yet. I think if food products would give us "healthy proportions" then the world would be okay(if this has anything to do with weight).