I started Tyler on Solids at 3 months, he wasn't taking his bottles at all so i thought i should try the 4-6 months food. He took to it straight away. He's not overweight, doesn't have allergeies (not that we've noticed yet) and overall a very healthly boy.
I have a few friends who have also started their babies b4 6 months and have had no problems at all, we all have healthy kids in the normal wieght range with no problems.
So like everyone else is saying it's totally up to you when you feel comfortable and when bub wants it.

ellie