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The great beer deabte

  1. Dec 2, 2005 #1
    When you drink a beer, it enters you cold, and leaves you warm. If you were to find the amount of energy required to raise the temperature of the beer, assuming that the energy is provided by yourself, you would find it to be greater than the caloric content of beer. If this is true (and it is), why doesn't drinking beer make you lose weight?

    Well, i can't figure it out and I'm not sure the answer isn't just some trick involving a misleading problem statement or something, what do you guys think?

    Last edited: Dec 2, 2005
  2. jcsd
  3. Dec 2, 2005 #2
    1) Not all the beer leaves you. You absorb most of the carbs and alcohol.

    2) Your body temperature is already what it is. The calories have already been expended to get it there. So when the cold beer enters your body, it starts absorbing heat rapidly. The proportional temperature-lowering effect on your much more massive body is minimal, and requires hardly any new calories to be expended to counteract it and keep your temp stable.

    so 3) you consume way more calories than are expended, and (skipping a afew steps) you gain weight.
  4. Dec 2, 2005 #3


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    Let's start with some math:

    Take a 12 ounce beer (355ml) and raise it's temperature from 2C to 37C. That's 12*355*35=107,100 calories.

    Now a typical light beer has on the order of 100 calories - which really is 100,000 calories. A difference of 7,100.

    But, the reason why that doesn't help you is biological. Your body regulates it's own internal temperature, and that energy just gets incorporated into the temperature regulation. The body doesn't need to cool itself so much, so it decreases the blood flow to your extremeties a little and there is no difference in energy production.

    Things change, of course, if having a couple of beers causes you to dance...
  5. Dec 2, 2005 #4


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    The dietary "calorie" is one kilocalorie, the heat necessary to raise one kilogram of water (or liter of beer) one degreee on the Kelvin or Celsius scale. Thirty dietary calories should bring a liter of beer from most serving temperatures up to body temperature --- same liter contains 30 g ethanol (a really light beer), which yield 10-15 kcal/g, 10-15 dietary cal/g. Let's go ahead and use the CHO dietary calorie for sugars from my Coke bottle, 4 cal/g --- still 4 times the energy necessary to bring the beer up to body temperature.
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