i've been pumping since i've returned to work last nov. Eventually, the milk supply did drop due to the environment that i've to face.. Imagine no facility for me to pump/ pump died on me / stress at work. Managed to sort everything out. Since there's no clean place to pump, i decided to pump in my car. last resort but then at least i persist. dual pump died on me, have to sent for repair, took 1 month to return & i survived on 1 battery operated pump. Life still goes on.
i always stick to my pumping schedule which means 7am...2.30pm...8.30pm. eventually your body will follow the shedule & produce more milk according to this timetable.
i do not bottlefeed my dear son at night, i will latch on so we co sleep so he can free access to the milk.
i guess this also play an important part to maintaining my supply.
Since you need to pump at work, it's always better to have a dual electric pump to shorten the time taken to express the milk. If you are planning to long term bf, it's definitely a good investment. As for the appetite, i do feel wobbly when i always finish pumping, so i have to eat. In order to produce milk so i will eat.