November 2011 - How big is yours?
We’re eating more than previous generations and the size of our bowls, plates and glasses has a lot to do with it.
Compare grandma’s wine glasses and the size of the bowls and plates in old dinner sets with modern utensils. Filled to the brim, an old-style wine glass held 90 or 100 mL at most.
Most modern wine glasses have a capacity of 350-450 mL, and even though (hopefully) they are not filled to the top, the average glass of wine poured in the home or in restaurants is 175 mL. Grandma’s wine glasses held the equivalent of one standard drink whereas the larger portion (and higher alcohol levels in modern Australian wines) means that one glass of wine is now equivalent to two standard drinks.
When two people share a bottle of wine, they each consume four standard drinks. That’s a lot of alcohol – and a lot of kilojoules!
Bowls tell a similar story.
An old-fashioned plate used for breakfast cereal held about 30g of puffed, popped or flakes grain. That looks pretty forlorn in a modern bowl.
Earlier generations would have considered the deep bowls we use for pasta or soups as serving dishes to use on a communal table.
Psychologist, Dr Brian Wansink from Cornell University, has shown that the size of food packages and the size and shape of glasses, bowls and plates increases consumption by 20-30%. One of his studies found that switching from a 30cm (12 inches) to a 25cm (10 inch) plate reduced consumption by 22%.
The shape of a glass also influences how much we drink. Most people, including experienced bartenders, pour at least 20% more into a short wide glass than a tall one.
This has also been used to advantage with soldiers who were at risk of dehydration in extreme circumstances.
Providing the soldiers with short, wide water bottles led to them drinking 38% more water. In all cases, however, neither those pouring nor those consuming liquids believed that they had consumed a different amount according to the glass or vessel used.
Wansink and a colleague recently published data in which they estimated the size of plates and the amount of food and bread depicted in 52 paintings of the last supper over the last thousand years.
Overall, the main courses had grown by 69%, plate size by 66% and a serving of bread by 23%.
The increase in portion size starts with children, although it is not apparent with toddlers who seem to stop eating food (but not necessarily liquids) when they are full. But the ability to listen to internal cues seems to disappear by five years of age when the more children are offered, the more they consume.
Researchers from North Carolina who checked portion sizes over almost 30 years, found big increases in how much children consumed both inside and outside the home.
The modern child now consumes larger serves of pizza, burgers, French fries (only at fast food restaurants), salty snacks, fruit drinks and soft drinks.
Average consumption of snack foods has been shown to be over 50% greater when nuts, pretzels or crisps are set out in large bowls.
At a Chinese buffet meal, overweight people start by taking a larger plate compared with people of normal weight.
They then tend to heap the plate without first walking along to observe what is available. (They also are more likely to use a fork rather than chopsticks and most sit facing the buffet table.).
However, in spite of consuming more kilojoules, those given large portions rarely report increased feelings of fullness and satisfaction.
Indeed many report satiety levels that are independent of how much they have consumed.
One classic study involved giving participants soup. Half were given a normal bowl of soup; the others were given soup in bowls that imperceptibly refilled as the soup was consumed.
These bowls resulted in over 70% more soup being consumed, although participants reported no greater satiety and did not believe they had consumed more.
When moviegoers in Philadelphia were given large buckets of popcorn, they ate more than when they were given medium-sized buckets, but claimed similar satiety levels. When given free popcorn that was either freshly made or 14 days old, those given a larger bucket of fresh popcorn ate 45% more. The container size is so powerful that even when they disliked the stale popcorn, those given larger buckets still ate over 33% more.
Another study asked people to rate their satiety when they consumed a meal in the dark or a lighted room. Although those eating in the dark were served more and ate 36% more, they estimated their consumption as no different from eating a meal in a light-filled room.
Serving sizes may also differ between countries. One study looked at similar foods available at fast food outlets and supermarkets in Paris and Philadelphia.
In every case, the North American versions were bigger; soft drinks by 50%, a confectionery bar by 41%, a hot dog by 63% and supermarket individual yoghurts by 82%. This no doubt contributes to the fact that obesity is five times greater in the US than in France.
There’s a fair bet that those selling us food or drinks have thoroughly researched the best way to increase purchase and consumption.
My advice is to buy smaller packets that will be shared with others (for example cereals, juices, flavouring powders for milk), and with foods in individual servings, recommend those that are genuinely small.