In 1978, I visited the USA with two colleagues on a mission to study meat quality. After travelling by car for many hours to reach Texas we got very hungry and stopped at a pizza joint in Oklahoma. We had a choice of small, medium, large and very large pizzas. We settled on one medium each as one should eat in moderation, but huge pizzas each covering half of the table arrived. We couldn’t even eat half of the pizzas.
This highlights that there is no universal measure of eating in moderation.
What is moderation?
Eating in moderation seems to be practical advice for a healthy diet, but a new study suggests that it is an ineffective guide for losing or maintaining weight. The scientists found that the more people liked a food, the more flexible their definitions of moderation were. And who doesn’t like pizza?
Of course moderation is a relative term that doesn’t allow a clear, concise way to guide behaviour as people think of moderation through their own objective lens. They tend to exaggerate what moderation is based on individual perceptions. Frugal Scandinavians might see a five-slice pizza as a satisfying amount, while more generous Americans might desire a ten-slice pizza.
The scientists concluded that people do think of moderation as less than overeating, so it does suggest less consumption. But unfortunately they do think of it as more than what they should eat. So moderation is more forgiving of their desires. The study adds to the growing body of knowledge that suggests people are poor judges of the amounts of food they eat.
In a general backlash against dieting there are now entire healthy eating movements oriented toward the idea of moderation. But those movements assume people can actually be good judges of what they’re eating and what constitutes an appropriate amount, which they obviously are not.
So what to do?
A recent Cochrane review of 69 food consumption intervention studies, published between 1978 and 2013, found that people consistently consumed more food and drink when offered larger-sized portions, packages or tableware than when offered smaller-sized versions. This is a little confusing and the researchers stated that the mechanisms underlying the “portion size effect” are not fully understood.
However, people generally perceive the amount served to them as representing an appropriate portion size and consume less when offered smaller portions and more when offered larger portions. The way in which food and drink is presented can also influence consumption. The size and shape of a plate or glass can alter perceptions of quantity and influence how much is consumed.
I repeat, the size of your plate seems to be important in how much you eat. And the size of your glass may influence how much you drink.
In support of this theory another study proved that a larger glass of wine — not the amount in the glass, but the size of the glass itself — might make you drink more. Researchers tracked purchases in a bar over 16 weeks, during which time different sizes of wine glasses were used, small (250 mL), standard (300 mL) or large (370 mL), while the serving of wine was kept at 175 mL. With larger glasses there was an almost 10% increase in wine consumption. It may be that larger glasses change our perceptions of the amount of wine, leading us to drink faster and order more.
Go for smaller tableware
Although it seems natural to eat less with reductions in the portion size presented, it is very interesting to notice the influence of the size of glasses and plates. The solution to overindulgence might be to reduce the size of your tableware. That could be quite helpful and easy to fix at home.