Why has the prevalence of obesity increased so drastically in the past few decades? The answer to that is a hugely complicated one, but one obvious factor we may not be giving enough weight to is the gargantuan increase in our average portion sizes.

Something as simple as how a food is served and presented to us can actually have a significant effect on how much of it we desire and how much of it we ultimately eat. For example, in one study in which a bowl of M&Ms was presented with either a small scoop or a scoop four times as big, people took far more M&Ms from the big scoop bowl!

Other evidence comes from a study in which adults were served either a nine or thirteen ounce serving of macaroni. The thirteen ounce group ate 43 percent more, and, even more interestingly, the two groups reported feeling similar levels of fullness afterward.

Nutritionists subsequently labeled the impulse to consume the entirety of a food item we are served a "unit bias," and a well-documented psychological phenomenon called a default bias may also be involved.

If a certain serving size seems like the "default", we will likely choose it without much thought rather than spend the mental energy to calculate what we actually need. This may be especially true for people who struggle with interoception, or reading their own internal hunger and fullness cues.

Unfortunately, one way that the food industry cons us into buying (and eating) more is by offering up larger portions, which can make their food seem more satisfying and thus more tempting, and thus like an appealing bargain compared to similarly priced but smaller items.


One study found that portions of almost all food products offered at restaurants in the early 2000s had increased relative to the portions typically offered in the 1970s. Unsurprisingly, this "supersizing" was most evident at fast food establishments.

For instance, a 1950s "regular" serving of McDonald's fries is now their "small," and a "large" is now about as big as their former "supersize." Almost all of the products the researchers found also far exceeded the FDA and USDA guidelines for what constitutes a standard portion size.

Other tactics food manufacturers use to con us into eating more include artificially deflating a product's calorie count by representing as a "serving" on a nutrition label an amount far smaller than most people would typically eat and offering "buy one get one free" promotions that could easily end with one person eating both.

In this manner, the food industry turned our once relatively moderate treats into health-destroying calorie bombs and began to normalize gluttony and overeating. Now, even those attempting to be moderate may choose a 16 oz "medium" soda, which is still twice the size of more reasonable 8 oz glass but looks downright conservative next to a 64 ounce 7-Eleven Double Gulp!

Plus, if we see food presented in inflated portions in our restaurants and on our supermarket shelves, we may start thinking such portions are normal and healthy when they are anything but, and then start modeling the way we eat at home on these distorted models.

Some experts suggest restaurants and manufacturers ought to start offering food in standardized sizes, so that customers would still have a choice as to which of these sizes to pick but would know exactly what they were getting even at different establishments, but we're a long way off from any regulations of the sort becoming a reality.

Mayor Micheal Bloomberg attempted to take action by banning the sale of soft drinks larger than 16 oz in New York City in 2012, but his amendment was eventually repealed. Such a measure may have been too little too late to change our mindsets about what a "portion" is, but at least he was trying to lead us in the right direction.

Current presidential candidate Bernie Sanders has also spoken out about the dangers of excess sugar consumption. While he opposed a proposed "soda tax" in Philadelphia in 2013, stating that it would disproportionately affect low-income consumers, he later voiced his support for a proposed "soda tax" that would instead be charged to the manufacturers of these deadly drinks.

So how can you outwit the forces that have driven American portion sizes out of control? Being vigilant about what you put on your plate or let in your mouth for one thing, even if that means measuring out your food until you get a better hang of estimation.


A moderate portion of meat should be about 3 ounces, while a serving of pasta or mashed potatoes should be about a half cup. Dressings and other fatty condiments should be limited to a tablespoon, while trans-fatty margarine should be stopped at only a teaspoon. For more suggested serving sizes, check out this list courtesy of the American Diabetes Association.

While it's difficult to overeat most whole foods (think of how much harder it would be to eat 5 apples than 5 cookies), once you enter back into the unwieldy realm of the processed, keeping an eye on a food's calorie content may also be useful.

Next, always portion your food into a bowl or plate rather than eating it from the bag or container, or, before you know it, you might end up scarfing down the whole thing. Then, try to start each meal with a healthy drink of water and a low-calorie and filling portion of vegetable before you move onto the more "costly" carbs, proteins, and fats.

Another portioning psychological quirk is that people are more likely to overeat if a variety of foods are served than when there are only one or two options, so don't feel like you have to try everything just because it's there!

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