What if you could lose weight simply by changing your plate?
There is a reason why Americans are piling on the pounds. Food containers – and therefore portions – have grown beyond all proportion.
An interesting – and curious – study published in the International Journal of Obesity looked at the sizes of the food and the heads of the apostles on 52 paintings of the Last Supper, and found that the meal portions and plate sizes have grown considerably over the last 1,000 years: plate sizes by 66% and bread size by 23%. Without going that far back in time, a glance at the average size of plates today reveals that they are nearly 50% larger than the first courses of the 1900s. If our grandparents ate from plates of about 21 centimetres in diameter, in other words, we now eat from plates of more than 32 centimetres! And this is not just for aesthetic reasons dictated by the dogmas of nouvelle cuisine.
Numerous studies (such as this one, this one or this one) have demonstrated that the larger our food containers are, the more we eat. This is for two reasons. The main one is a simple optical effect studied by Joseph-Rémi-Leopold Delboeuf and developed by Hermann Ebbinghaus, which we can apply to food: when you see the same amount of food placed on a larger plate, it creates the illusion of being much less. This means that we fill up larger plates with more, and smaller ones with less.
As a result, then, in the first case we eat more (and here’s the second reason) because for socio-psychological reasons we tend to finish what we’ve got on our plates, especially if it’s particularly appetising.
Still on the subject of optical perceptions, a study by the Georgia Institute of Technology found that one of the few ways to reduce this perception is through colour: if we create a contrast with the food by changing the colour of the plate, we tend to serve portions approximately 20% smaller, and by changing the colour of the tablecloth these become 10% smaller. Colour combinations therefore increase the desire for food, while a smaller plate deceives the eye when it comes to perceiving quantity and makes us eat less.
All these studies, effectively summarised in this infographic , show that the sizes of plates and other food containers underlie obesity problems, especially in the United States where weight gain has grown exponentially since the 1980s. If we then add the fact that more and more people (especially poorer people) eat junk food, it’s… game over.
This partly explains why people such as the French, who notoriously consume fatty foods, are thin, or why Asian people are. Their food containers, and therefore portions, are limited. The size of an average yoghurt in a French supermarket, for example, is 125 g, while in the US it’s 227 g, and similarly a Coca Cola is 330 ml in France vs 500 ml in the US. An average Chinese restaurant in France offers 244 g portions where in the US this would be 418 g, and that’s without going into fast food where French portions are around 189 g, compared to 256 g in the US.
All of this is closely linked to life expectancy: the Japanese lead the field with an average age of 83, followed by the Australians and Israelis. In Italy, we can hope to see the sun rise until the age of 82, and the French until the age of 81. For Americans, however, this goes down to 79. Paul Rozin, professor of psychology at Pennsylvania University, explains it very clearly in this brilliant talk.