The March of the Adipose is the name given to an event in 2009 London where 10,000 Adipose were born and marched to their Nursery Ship, where they were collected by their "parents".
Prior to the March
The Adipose Pill was given to fat Humans by Matron Cofelia (under the alias Miss Foster). The Adipose were produced from the fat of those who had been on the Adipose diet. Matron Cofelia activated her signal to induce the birth of the Adipose babies.
During the March
They marched along the streets of London towards the ship. The machine was deactivated by the Doctor using two Adipose Pill Necklace but 10,000 Adipose had already been born. The Adipose walked to Adipose Industries HQ where Miss Foster was waiting. Soon after, the Adiposian Nursery Ship descended and used levitation beams to lift the Adipose up to the Nursery ship.
After the March
The Adiposian First Family decided that they no longer needed Matron Cofelia, as she was an accomplice and a liability and deactivated the levitation beam carrying her and she fell to her death. (DW: Partners in Crime)
Alternative March
In Donna's World, the Doctor had died and the March of the Adipose occured in America instead of UK, because Britain was closed off from the rest of the World. 60 million Americans were killed when they were fully converted into Adipose children. (DW:Turn Left)