I agree with Caro. Some babies are ready for solids before the recommended 6 months, but most aren't which is why 6 months is the recommendation. And even if they are ready before, it doesn't hurt (usually) to hold off until 6 months as milk is their primary nutrition source until 12 months. 7 weeks is way too early.

WRT food labelling, the products that say they are suitable from 4 months are no different to the ones labelled suitable from 6 months. The companies exploit a loop hole in the law. The Australian guideline is 6 months so no baby food should be labelled as suitable from 4 months, but overseas companies are able to get around this.