Have you heard of the Smaller Plate Study (aka The perils of large plates: waist, waste and wallet) by Drs. Wansink and Ittersum?
They found that reducing plate size from the traditional 12″ to 10″ resulted in about 22% less calories being served up. (We typically eat about 92% of what we serve ourselves) They predicted that using a smaller plate for a year could lead to weight loss of about 8kg.
However, once the plate size went below about 9.5″ a lower limit was reached probably because people realised they were tricking themselves and went back for seconds and thirds!
Here’s a ten inch plate on the left and an eleven inch one on the right….. only a small difference but an easy way to control portion size.