The more we’re served, the more we eat.
So says a new series of research that shows the larger the portion, the greater the number of calories we consume – with little concern for how hungry we actually are or how big a portion should be. These findings have significant implications for Americans’ growing waistlines and health problems.
“Portion size has been suggested to be one of the major culprits in the obesity epidemic,” said Barbara Rolls, a nutrition researcher and professor of biobehavioral health at Penn State, who conducted the research.
In one study -– which Rolls believes to be the first academic research to examine portions in a restaurant, not a lab -- she and her team served an average portion of a baked pasta dish, along with one that was 50 percent larger. The entrees were served in the same sized dish but on different days, so both would appear the same and diners would have no basis to compare them.
When served the regular entrée, people ate an average 399 calories worth of pasta; those who ate the larger portion consumed an average 571 calories, according to the study, published in the March edition of the journal Obesity Research.
Surprisingly, when eating the larger portion, diners also ate more accompanying side dishes, and tacked an average 159 extra calories onto their meals. Rather than their stomachs accommodating the outsized entrée by eating less of everything else, or eating less during another meal, they simply absorbed the extra calories.
“People think, ‘Well, my body will take care of it,’” Rolls said. “They’re deluding themselves.”
In another study, published in the Journal of the American Dietetic Association, Rolls and other researchers found similar results when feeding subjects hero sandwiches. Over the course of four weeks, they provided lunches to 75 people: a sandwich, some potato chips, a chocolate mint and water. The subjects had to eat the potato chips and the mint but could eat as much of the sandwich as they wanted.
Over the course of the experiment, the researchers varied the sizes and calorie counts of four sandwich sizes from six inches (668 calories) to 12 inches (1,337 calories). After eating, participants' ratings of their own fullness was largely the same, no matter the sandwich size.
Yet as the sandwich sizes grew, people ate more total calories. Women averaged 515 calories for a six-inch sandwich and 674 calories for the 12-inch version; men consumed 635 calories on average for the small hero and 990 for the largest, in addition to the mint and chips.
Speaking of potato chips, another experiment by Rolls showed that people served chips several hours before dinner consumed more overall calories when they ate a larger bag of chips; they didn’t generally compensate for their pre-dinner snack.
'Desire for big things'
Eating whatever we’re served? The first reaction might be to blame Mom and Dad for telling us to clean our plates.
But it’s not necessarily that simple. Among other things, we’re eating away from home more often, now spending nearly half our food dollars at restaurants and dining establishments, according to a USDA study.
That should be considered, Rolls said, in light of decades of many major restaurants marketing food’s size -– not quality -- as a value proposition. By comparison, European eaters tend to seek out smaller portions and focus on quality over quantity.
The findings also appear to be another sign the supersizing trend has come home to roost in its rather large nest.
At the same time, the United States continues to spend less per capita on food than any other nation, USDA statistics show. And U.S. restaurants tend to maximize the overall size or weight of meals, often by using cheap, starchy staples. Conversely, foods with less fat and more nutrients are usually more expensive and in shorter supply on menus.
“Food is very cheap compared to everything else,” said Rolls, who in her book “Volumetrics” argues that high-volume, low-calorie foods like vegetables can effectively tackle the big-portion problem. “It is a problem now that it’s more expensive to eat a healthy diet.”
This bigger-is-better notion has broad implications both for those eating food and those serving it to them.
“Our culture feeds right into our desire for big things,” said Lisa Young, a nutritionist and New York University researcher. “I think the only way we’re going to lose weight, ultimately, as a population is to have this conscious message that we don’t need to eat so much.”
Portions keep growing
Young has found that while recipe sizes haven’t changed much since the 1970s, the number of portions per recipe has shrunk. In 2002, she and nutrition researcher Marion Nestle showed that many common ready-to-eat items far exceed the government’s recommended portion sizes: a muffin was over 300 percent the recommended size; a chocolate chip cookie was 700 percent bigger than recommended.
And last year, they looked at how basic serving sizes of popular brands have grown through the years. Coca-Cola’s original serving in 1916 was 6.5 oz.; now it’s 12 oz., with 20 oz. bottles popular, too. The first McDonald’s hamburgers were 1.6 oz.; that size is still available, but the Big Mac and Quarter Pounder clock in around 4 oz.
Yet the trend toward supersizing has showed signs of reversal. After years of complaints by nutritionists and consumer groups, McDonald’s announced it was ending its supersized meal offers, and it has recently introduced new salads and fresh foods. Pepsi has begun marketing an 8-oz. can, and Coke has long had 8-oz. servings, though they have been infrequently marketed.
Still, Young believes shoppers are so hard-wired for value that we won’t embrace smaller sizes until the larger ones are no longer available. It’s hard to shell out 90 cents for a small can of soda when a 20-oz. bottle for $1.50 is right next to it.
“The incentive on the consumer is to spend a few cents more to get much more,” Young said.
Indeed, though corporate nutritionists and meal planners are likely to take a harder look at serving size, Rolls said the ultimate push must come from those of us who keep eating and drinking in ever-expanding amounts, demanding that Americans get portions to fit a healthier lifestyle.
“If we keep telling them what we want, they’ll give it to us,” she said. “It’s up to us as consumers to let the industry know that we don’t really want that much food, that we would rather have better quality.”
On the other hand, she acknowledged, “We don’t want to pay a heck of a lot more for less food.”