Lunavix,
I'd second what Metrobaby says - excellent antidote to health visitors is not to attend their baby clinics for 'weigh ins'. Fwiw ds has 32 fl oz of milk a day and about 6 cubes of food like your baby. He has lovely chubby legs and a really round tum which I think are adorable.
Dot -re the 'arthritic' feelings...after I had dd for months afterwards when I got up from a sitting position my feet would be stiff and inflexible and I would hobble like a 90 year old for a few minutes until it wore off. Didn't get a recurrence after this pregnancy.
On the day time sleep thing, I really like ds' pattern. He has about 30 minutes roughly 2-3 hours after first waking in the morning, and then he has 1 - 1.5 hours at lunch time. He doesn't then take any further naps until he settles for the night (around 18.45)...
Also much impressed by Fennel giving dd3 the spoon to feed herself. Now I know I'm a bit anal, but honestly I couldn't stand the mess!!! Ds does make a grab for the spoon, but I just use my superior fine motor skills to deftly dodge him (unfair advantage there haven't I, over a 6 month old baby).