Have you ever had one of those nights where you open a bottle of wine (or crack open a carton of chocolate milk) and a couple hours later it is gone. You couldn’t have had that much; you just poured one glass right? Or was it two? It must have been a smaller bottle or your friend helped you finish it quicker. It couldn’t have been the shape of your glassware… or could it?

red vs white wineIt may be a surprise, but the diameter and height of glassware can distort our perception of how much we pour for ourselves and how much we consume. The recommended serving of wine is 5 fluid ounces. How many of us actually know what that looks like? The typical wine glass holds around 10 ounces, but is usually only filled halfway. If the glass were wider, would you notice? If the glass were longer in the bulb, would you pour more? If the glass were in your hand versus on the table, how would that affect how much you served?

Brian Wansink PhD, who researches changing eating habits and is the director of the Cornell Food and Brand Lab, has studied and found that all of these aspects and characteristics surrounding our dishware and glassware affect our portion sizes. In one study, Wansink found that the width of the glass, the color of the drink, and the position of the glass positively affects how much subjects poured in their glass; pouring more as the width increased.  When the drink was harder to see (clear), or when the drink was on the table versus in their hand they poured more also. This is important because liquid calories are the most deceptive; they go down easily and stick. A single 5-ounce portion of wine is 110 calories ± 10; if that portion was doubled in addition to consuming a standard diet, a pound could sneak on every two weeks.

This is not limited to wine; other studies have shown it goes for short wide glasses being perceived to hold less.  “As a result of the distortion, those given short glasses poured and consumed more than they thought, while those given tall glasses poured and consumed relatively less” (Wansink p. 458). Think about that soda you may have had earlier today; do you know how many ounces that cup held?

wide base and tall glass

According to a French marketing professor named Pierre Chandon sourced by the New York Times writer, Tara Parker-Pope in a study including 294 subjects, participants could not accurately guess how many ounce were in various cups ranging from the standard from years ago, 6.5 ounces, to the 50 oz. “Double Gulp”. Respondents guessed that the larger cups contained anywhere from 20 to 40 percent less than they actually did. Parker-Pope rationalizes, “the reason comes down to the fact that the human brain has a surprisingly tough time with geometry and often can’t accurately gauge when an object has doubled or even tripled in size” (“Misconceptions of Soda Serving Size”).

The shape of that cup holding the monstrous Big Gulp, as we know, plays a big part. Who can turn down a dollar for a 42oz thirst quencher at the local drive-thru? As consumers we are groomed to jump at the deal. Listen to the wise saying, a moment on the lips, a lifetime on the hips.  A 42 oz. Pepsi without ice is about 520 calories, that’s a quarter of the daily value baseline. It may be time to hoof  it sans cup holder and ignore the drive thru altogether.

Here are some ways can you do to avoid the liquid calorie booby trap

Fruit water glass

One easy step to avoid packing on the pounds is to switch to water. In fact, it is even better for you to drink more water and to stay well hydrated. To liven up your H2O, try adding fruit slices or refreshing herbs.

If switching to water seems too difficult, try changing your glassware. Remember, participants poured and consumed less when using taller, slender glasses relative to their equal-volume, yet stout companion. This simple switch can save hundreds of calories and eventually pounds in the long run.

Other simple tricks include

  • Watering down your drink
  • Alternating between water and calorie-dense beverages
  • Be aware of the number of servings in a glass/can (compare serving size to total servings)
  • Reduce the amount of add-ins to your coffee
  • Eat whole fruits/vegetables instead of their juice counterparts

Where the calories hide in our beverages

Beverage Serving Size (fl. Oz) Average Calories









Sports Drink(ex. Original Gatorade)



Regular Soda(ex. Can of Coke)



Commercial Smoothie


220 (ex. Odwalla Mango Tango)

V8 Juice Drink


90 (ex. Original)

Kid’s Juice Box


120 (ex. Mott’s Original)

Energy Drink (regular)


100 (ex. Monster Energy)

Beer (Regular)



Wine (Red)



Liquor (vodka)



Sources: Alcohol calorie calculator | National Institutes of Health

When comparing all of the different beverages, it can be eye-opening to see how dense with calories some beverages actually are and how small a serving can be; the standard Gatorade bottle is 20 fluid ounces, roughly 2.5 servings (8 oz. each). It is easy to guzzle down multiple servings, especially when they are alcoholic beverages. An interesting bite to chew on for next time………where do all of the calories in these drinks come from and why is it that they don’t fill our stomachs quite like an apple or a tablespoon of peanut butter does?


Parker-Pope, Tara. “How Can a Big Gulp Look So Small?” The New York Times. The New York Times Company, 21 June 2012. Web. 11 Nov. 2013.

Walker, D., Smarandescu, L., & Wansink, B. (2013). Half full or empty: Cues that lead wine drinkers to unintentionally overpour. Substance Use & Misuse, Early Online: 1-8. (doi:10.3109/10826084.2013.832327).

Wansink, Brian, and Koert Van Ittersum. “Bottoms Up! The Influence of Elongation on Pouring and Consumption Volume.Journal of Consumer Research 30.3 (2003): 455-63. Print. (doi:10.1086/378621)

5 thoughts on “Fill it Up? How the shape of your glass may affect your shape

  1. Hilary, I really enjoyed this blog post. Most of us think of a glass as just one serving, never thought it would be heavier than I believe. At least now I know how the shape of the glass and the color of the wine may influence our drinking habits. This is a great tip for people who are watching their calorie intake and for people who are trying to abstain from drinking alcohol.

    • Hi Susan,
      Glad you liked the post. It is really interesting how our senses can affect how much we perceive we are having.

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  3. too good that i have to print it and post in on my dad’s fridge! 😀 that way he will definitely be cautious about his drinking habits. Thanks Hilary!

    • Hi Katie,
      Glad to be of service 🙂 I hope it helps your dad to realize what a portion is; Even if it doesn’t slow him down at least he will know how much he is drinking and be more aware.

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