after that just go to the lab
where can i find the lab? or how can i unlock it? i have just unlocked the buffet if some hints about my progress are needed (PC is 118 kg)
The lab will be unlocked automatically when you reach a weight were the PC worries about becoming immobile.
so i will need to wait untill then to fatten Diane up?
Yes, to fatten Diane up you need the lab.