While I was flying home to a family reunion last summer, I sat next to a Marine Drill Sergeant on the plane. When he found out that I was professor, and that I taught a class on obesity, he laughed. “There is no reason for a whole class on why we are fat,” he chuckled. “I tell all my new recruits loosing weight is easy. CICAS: Calories In, Calories Out, Stupid. You can eat all you want, as long as you make sure you burn all you eat.” Admittedly, his statement is true. But it kept me thinking, then why are people still heavy, and only getting heavier? If it really did boil down to burning all the calories we ate, then there is convincing evidence that Americans should be fit, if not loosing weight. Considering that the health and gym memberships are a $25 billion industry, and during economic downturns gym memberships experience growth (albeit small), it appears that Americans are working hard at the ‘calories out’ aspect. So what is happening with the “calories in’ part?
If we look closely at calorie consumption in the United States, we find that most people eat more calories on a given day then they really need. In 2000 the US Department of Agriculture found that the average daily caloric intake was 2,900. That is almost 700 calories more than what is recommended for males 18 – 30 years of age. And looking back at old editions of the Joy of Cooking, recipes have increased their calorie content by 37%, mostly because the portion sizes have increased. And it does not take that many extra calories each day for you to gain weight. A study by the University of California Wellness Center found consuming an extra 19 calories per day more than you burn results in gaining 2 pounds over a single year.
But what has only 19 calories? It is hard for us to picture something that is only 19 calories – and that is because we really are not good at judging calories. To be fair, it is hard. Equal amounts of two foods do not mean have equal calories. Take, for example, cucumbers and M&Ms. A medium sized cucumber has 19 calories, while a single, Fun Size bag of M&Ms has 103 calories. You would have to eat five medium sized cucumbers to get about the same number of calories as the bag of M&Ms. Put another way, you only get to eat about 3-5 M&Ms to get 19 calories. So if you eat an extra 3-5 M&Ms each day, for a year, you would gain 2 pounds.
In order to consume fewer calories we need to do something very simple, but admittedly very hard: Stop eating. Or maybe, stop eating when we are full. Americans, however, ignore when our bodies tell us it is time to stop eating. Psychologist Brian Wansink asked Americans diners (from Chicago) and French diners (from Paris) how they know when to stop eating a meal. The French said they stopped eating when the food no longer tasted good, or they were no longer hungry. The Americans, however, said they knew it was time to stop eating when there was no more food left on the plate, or (worse yet) when the television show they were watching while eating was over. In other words, American’s rely upon external cues to help us determine when we have had enough calories.
Probably the best example of this is another study done by Wansink and colleagues, called the Bottomless Bowl of Soup. In this study, 54 males at a university were invited to participate in a ‘soup-only’ lunch, and then answer some questions about the soup. Each diner sat at a table with three other people, and was told to enjoy as much soup from his bowl as he wanted. The participants talked and ate, as one would during a normal lunch.
What the participants did not know was half of the subjects had a ‘self-refilling’ bowl. That is, the bowls were connected to a pot of soup by a large tube that ran under the table, and was hidden from view. This allowed Wansink and his colleagues to slowly refill the soup bowls, so that the diner would never reach the bottom of the bowl. Wansink gave each table 20 minutes before interrupting the meal and asked a series of questions. One was how each participant knew to stop eating the soup, and more than half of the participants stated, “When the bowl was empty.” Since half of the bowls were refilling, they would never get empty – and indeed only one person stopped eating and realized the trick. This was because he attempted to pick the bowl up from the table to drink his soup (It turns out, compared to the French, Americans also have poor dining manners)!
Those participants with a bottomless bowl of soup ate more than those at the table with normal bowls. And not just a little more – but almost twice as much (14.7 ounces of soup for the bottomless bowl group, compared to 8.5 ounces for the normal). Wansink also asked each diner how many calories he thought he had consumed. Here the two groups were similar, each thinking they had consumed about 125 calories of soup. In reality, the group with the normal bowls consumed about 155 calories, while those with the bottomless bowls consumed nearly 270 calories!
But who really eats from a bottomless bowl of soup? Or drinks from the bottomless bottle of soda? The answer, of course, is no one. Not normally. But the average American does eat more calories each day than really needed. We do not pay attention when our bodies tell us to stop eating – but instead we pay attention to much food we have available. And this is bad. As technology and science increase our ability to grow and produce more food, Americans will most likely continue to eat more. In fact, we know this is true already. A pair of Australian economists downloaded from the US Department of Agriculture the amount of raw grains American farmers had grown for a 10-year period. As expected, they found that America increased food production over time, most likely due to better technology for growing and harvesting grains. The Australians then compared this increase in food production with the average increase in weight for the same 10-year period. And surprisingly (or not, considering what we have just discussed in the previous paragraphs) the increase in food production matched perfectly the increase in weight. Meaning, gives us more food, and we’ll eat more food. We just cannot seem to stop those calories from coming in!