We like to buy products that come with larger packages, because, we think we’re saving money doing so:
Wal-Mart sold $284 billion worth of goods in 2005. Groceries accounted for about one-quarter of that amount, but that meant $64 billion, and rising. Many food companies do a third of their business with this one retailer. Wal-Mart does not have to demand slotting fees. If a food company wants its products to be in Wal-Mart, it has to offer rock-bottom prices. Low prices sound good for people without much money, but nutritionally, there’s a catch. Low prices encourage everyone to buy more food in bigger packages. If you buy more, you are quite likely to eat more. And if you eat more, you are more likely to gain weight and become less healthy.
When we buy larger portions, do we actually consume more?
Imagine that a professor from a local university approaches an organisation to which you belong–such as a Parent Teacher Association–and proposes a fund-raiser for your organisation. He’ll donate $20 to your organisation in your name if you come to the school kitchen one evening and make a spaghetti dinner for yourself and your spouse. He’ll even provide the food–a medium-size box of spaghetti, a medium-size jar of spaghetti sauce,and one pound of ground beef.
What you won’t know, however, is that half of the people in your organisation will receive not the medium size, but a large box of spaghetti, a large jar of spaghetti sauce, and two pounds of ground beef. What you also won’t know is that after you finish dinner, he’ll weigh how much spaghetti, pasta, and ground beef you have left, and how much you cooked but didn’t eat.
We’ve done dozens of similar studies with dozens of different foods. With spaghetti, for instance, we found that the people who were given the large package of pasta, sauce, and meat typically prepared 23 percent more–around 150 extra calories–than those given the medium packages.
Did they eat it all? Yes. We find over and over that if people serve themselves, they tend to eat most–92 percent–of what they serve. For many of the breakfast, lunch, and dinner food we have studied, the result is about the same–people eat 20-25 percent more on average from the larger packages. For snack foods, it’s even worse.
THE BOTTOM LINE: WE ALL CONSUME MORE FROM BIG PACKAGES, WHATEVER THE PRODUCT. Give people a large bag of dog food, they pour more. Give them a large bottle of liquid plant food, they pour more. Give them a large shampoo bottle or container of laundry detergent, they pour more. In fact, with the 47 products we’ve examined, the bigger the package, the more they use. There was only one exception: liquid bleach. Most people know that if they use too much, their socks and shirts experience a religious conversion. They become holy.
“Why do we automatically eat or pour more from big packages? Because big packages (like big portions) suggest a consumption norm–what is appropriate or normal to use or eat.”
As all of our studies suggest, we can eat about 20 percent more or 20 percent less without really being aware of it. Because of this, we look for cues and signals that tell us how much to eat. One of these signals is the size of the package. When we bring a big package into our kitchen, we think it’s typical, normal, and appropriate to mix and to serve more than if the package were smaller.
When did we start to lose track with our own desires and forget about what or how much we really want?
Surprisingly, probably between the ages of three and five, long before we were aware.
A fat-forming transformation in our eating habits takes place between the ages of three and five. You can give three-year-olds a lot of food, and they will simply eat until they are no longer hungry. They are unaffected by serving size.
By age five, however, they will pretty much eat whatever they’re given. If they are given a lot, they’ll eat a lot, and it will even influence their bite size. This has been vividly shown by leann Birch at Penn State and Jennifer Fisher at the Baylor Medical School. Wen they gave three-year-old children either medium-size or large-size servings of macaroni and cheese, the three-year-olds ate the same amount regardless of what they were given. They ate until they were full, and then they stopped. The five-year-olds rose to the occasion and ate 26 percent more when given bigger servings. Almost exactly the same thing happens to adults. We let the size of a serving influence how much we eat.
Remember that none of us really seem to know the amount of a “correct” serving size.
Better be careful next time you pick a full 2-liter bottle of coke! If you end up downing more in one go, it might miraculously serve to lose you money and save you fat at the same time.