this was on another thread:
It may be useful to know that in some european countries the guidelines for weaning gomuhc more on weight etc than age. I think this is more sensible as babies can vary so much, at 4 months my baby was only 11lb, my friends baby was 11lb when born!
The swedish(I htink) guidelines are weaning can start when:
All of these criteria should be met
Baby is AT LEAST 16 weeks old
Baby has doubled birth weight
Baby weighs over 14lb
Baby can hold head up unsupported by you
other signs
Baby drinks 35oz+ milk a day
Baby is hungry in between usual feeds
Baby finishes a full (8oz) bottle or drains both breasts and still is hungry
Baby starts waking more frequently
Baby shows interest in food - grabs for your food
Baby can swallow food
They recomend that babies who need more than 40oz of milk a day probably need weaning, thats the usual amount of milk for a baby weighing 15-17lb.
However I wouldn't start with jars, I'd start wiht baby rice and then introduce pear and sweet potato.
The WHO guidelines are based on the best advice for the WHOLE world, so they recomend the extended BFing and 6months+ patrially because in non developed and hotter countries (which have the majoriy of the worlds population in them) its really important to make sure baby stuff is sterile, with water supplies being bad the easiest way to do that is through extended breastfeeding
however you don't live in a third world country and if you feel that your baby needs weaning before 6 months then talk to your health visitor. Hopefully the stuff i posted will give you some ideas of the types of things which you can look out for.
(I weaned at 51/2 months and DS is now 18 mo with no apparant ill effects!)