Customer Alex Cuff is seen through the window as he eats cereal at the "Cereal Killer Cafe" in east London December 10, 2014. Identical twin brothers hope they have ticked the right boxes, and ordered in the right flavours, for their new "Cereal Killer Cafe" in London serving only cereal, with toppings and milk. Alan and Gary Keery from Belfast offer 120 different cereals from around the world at the cafe which they say is the first of its kind in London and opened on Wednesday. They also offer 20 toppings and 30 different types of milk. REUTERS/Luke MacGregor (BRITAIN - Tags: FOOD SOCIETY TPX IMAGES OF THE DAY)

Customers eat cereal at the "Cereal Killer Cafe" in east London December 10, 2014. Identical twin brothers hope they have ticked the right boxes, and ordered in the right flavours, for their new "Cereal Killer Cafe" in London serving only cereal, with toppings and milk. Alan and Gary Keery from Belfast offer 120 different cereals from around the world at the cafe which they say is the first of its kind in London and opened on Wednesday. They also offer 20 toppings and 30 different types of milk. REUTERS/Luke MacGregor (BRITAIN - Tags: FOOD SOCIETY)

Customers Charley Peers (L) and Libby Girdham eat cereal at the "Cereal Killer Cafe" in east London December 10, 2014. Identical twin brothers hope they have ticked the right boxes, and ordered in the right flavours, for their new "Cereal Killer Cafe" in London serving only cereal, with toppings and milk. Alan and Gary Keery from Belfast offer 120 different cereals from around the world at the cafe which they say is the first of its kind in London and opened on Wednesday. They also offer 20 toppings and 30 different types of milk. REUTERS/Luke MacGregor (BRITAIN - Tags: FOOD SOCIETY)

Customers Sydney Fortune (L) and Julia Lessere eat cereal at the "Cereal Killer Cafe" in east London December 10, 2014. Identical twin brothers hope they have ticked the right boxes, and ordered in the right flavours, for their new "Cereal Killer Cafe" in London serving only cereal, with toppings and milk. Alan and Gary Keery from Belfast offer 120 different cereals from around the world at the cafe which they say is the first of its kind in London and opened on Wednesday. They also offer 20 toppings and 30 different types of milk. REUTERS/Luke MacGregor (BRITAIN - Tags: FOOD SOCIETY)

Alan Keery (C) serves cereal at the "Cereal Killer Cafe" in east London December 10, 2014. Identical twin brothers hope they have ticked the right boxes, and ordered in the right flavours, for their new "Cereal Killer Cafe" in London serving only cereal, with toppings and milk. Alan and Gary Keery from Belfast offer 120 different cereals from around the world at the cafe which they say is the first of its kind in London and opened on Wednesday. They also offer 20 toppings and 30 different types of milk. REUTERS/Luke MacGregor (BRITAIN - Tags: FOOD SOCIETY)

Staff Abigail Hickey (L) and Joshua Puleston serve cereal at the "Cereal Killer Cafe" in east London December 10, 2014. Identical twin brothers hope they have ticked the right boxes, and ordered in the right flavours, for their new "Cereal Killer Cafe" in London serving only cereal, with toppings and milk. Alan and Gary Keery from Belfast offer 120 different cereals from around the world at the cafe which they say is the first of its kind in London and opened on Wednesday. They also offer 20 toppings and 30 different types of milk. REUTERS/Luke MacGregor (BRITAIN - Tags: FOOD SOCIETY)

A customer inspects a box of imported cereal at the "Cereal Killer Cafe" in east London December 10, 2014. Identical twin brothers hope they have ticked the right boxes, and ordered in the right flavours, for their new "Cereal Killer Cafe" in London serving only cereal, with toppings and milk. Alan and Gary Keery from Belfast offer 120 different cereals from around the world at the cafe which they say is the first of its kind in London and opened on Wednesday. They also offer 20 toppings and 30 different types of milk. REUTERS/Luke MacGregor (BRITAIN - Tags: FOOD SOCIETY)

\Milk and bowls of cereal sit on a tray at the "Cereal Killer Cafe" in east London December 10, 2014. Identical twin brothers hope they have ticked the right boxes, and ordered in the right flavours, for their new "Cereal Killer Cafe" in London serving only cereal, with toppings and milk. Alan and Gary Keery from Belfast offer 120 different cereals from around the world at the cafe which they say is the first of its kind in London and opened on Wednesday. They also offer 20 toppings and 30 different types of milk. REUTERS/Luke MacGregor (BRITAIN - Tags: FOOD SOCIETY)

Boxes of cereal and a menu board are seen at the "Cereal Killer Cafe" in east London December 10, 2014. Identical twin brothers hope they have ticked the right boxes, and ordered in the right flavours, for their new "Cereal Killer Cafe" in London serving only cereal, with toppings and milk. Alan and Gary Keery from Belfast offer 120 different cereals from around the world at the cafe which they say is the first of its kind in London and opened on Wednesday. They also offer 20 toppings and 30 different types of milk. REUTERS/Luke MacGregor (BRITAIN - Tags: FOOD SOCIETY)

Boxes of cereal sit on shelves at the "Cereal Killer Cafe" in east London December 10, 2014. Identical twin brothers hope they have ticked the right boxes, and ordered in the right flavours, for their new "Cereal Killer Cafe" in London serving only cereal, with toppings and milk. Alan and Gary Keery from Belfast offer 120 different cereals from around the world at the cafe which they say is the first of its kind in London and opened on Wednesday. They also offer 20 toppings and 30 different types of milk. REUTERS/Luke MacGregor (BRITAIN - Tags: FOOD SOCIETY)