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Medical Weight gain question

  1. Oct 2, 2007 #1
    Assuming your body is an engine which converts matter to energy, and that mass x gravity = weight, still holds true within the human body.

    How is it possible in a 24 hour peroid to eat 8 oz of food (dry weight) and 16 oz of water (dry weight) and 8 oz of milk (dry weight) and still gain two pounds? I know 8+16+8=32, which is two pounds, but there is some subtraction to do.

    Subtract 8 oz of urine (dry weight) and 8 oz of excrement (dry weight) to the math.

    Subtract what you sweat out, what the moisture in your lungs exhale, I'm guessing at least one pound a day (16 oz), double that on a hot dry day, I'm still trying to look this one up.

    Subtract the btu's to run a typical human body, btu's are given a weight factor somewhere, maybe in one of the links below.

    http://ct.water.usgs.gov/education/trivia.htm [Broken]

    I gained two pounds in one day (effect), over-ate at dinner (cause), but the math does not add up.
    Last edited by a moderator: May 3, 2017
  2. jcsd
  3. Oct 2, 2007 #2
    Here's a thought, the human body is an engine which can turn potential energy (calories) into mass (stored energy/fat).

    Therefore; energy in equals mass stored and when sitting on the toilet mass out the back hatch.
  4. Oct 2, 2007 #3
    You are some sort of metabolic crackpot violating conservation laws. You should be banned.
  5. Oct 2, 2007 #4
    A waist is a terrible thing to mind. If you use the cheapo scale in my bathroom, you could gain or lose two pounds just by stepping off and stepping back on. Were you wearing the same clothing (or lack thereof) at the two weighings? I recommend that you weigh yourself once a week in the nude at the same time of day and day of week. Don't lose more than a pound a week unless you are morbidly obese. In that case work with a doctor.
  6. Oct 2, 2007 #5
    You went an entire day drinking only 16 ounces of water?!
  7. Oct 2, 2007 #6
    My scale is very accurate, compared it to a doctor's scale and decided not to take it back. It's digital and displays in 1/2 lb increments.

    A good dump is a 1/2 weight loss, a really good dump is one pound, a bragging rights deposit is 1-1/2 lbs and the mother of all bombs which I've only done once in five years is a whopping two pound baby boy I called Brownie.:rofl:
  8. Oct 2, 2007 #7
    That's 24 oz if you count the skim milk. I'm just thinking back, did no actual counting or measuring that day.

    I did not count the two cups of coffee because it's a slight negative anyway.
  9. Oct 2, 2007 #8
    What else didn't you count?
  10. Oct 2, 2007 #9
    Well, it's kind of embarrassing.:redface:

    I'll just watch what I eat all week, plus the weekend. It's normal for me to dip up and down a couple of pounds, just shocking to have the gain all in one day. I never get a similar loss all in one day like that unless it's another Brownie birth, and I don't really look foreword to another one of those.

    Reminds me to sent a mothers day card out. Sorry what I put you though mom.:wink:
  11. Oct 2, 2007 #10
    Don't trust your scale too much. I weigh myself with a precision scale we use at the lab where I work, and I see my weight oscillate up to a lb in either direction over a couple days.

    If you want accurate measurements you have to average, I wouldn't worry too much about it.
  12. Oct 2, 2007 #11


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    And did you weigh yourself both times at the same time relative to using the bathroom? Otherwise, your previous day's meals will affect how much is still retained within your bowels/bladder. The type of meal you eat will also affect the rate of digestion. For example, with a high fiber diet, you will have a bowel movement sooner than if you eat a diet low in fiber, so even if weighing yourself at the same time of day, you will get some fluctuation.

    If you're feeling compelled to so carefully measure the weights of both the food you're consuming and the waste you're expelling, I would also suggest you seek the advice of a physician/psychiatrist...this is indicative of an eating disorder.

    (And as a moderator note, please stick to science here, and avoid the slang terminology.)
  13. Oct 2, 2007 #12


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    By the way, how do you get a dry weight on water? A dry weight on milk would be just the milk solids, with the water evaporated off. I'm assuming that was actually a wet weight also. :uhh:
  14. Oct 2, 2007 #13
    This bothered me too, so I looked it up. It turns out that a pint of water (16 oz. liquid measure) is a pound (approx.)
  15. Oct 3, 2007 #14
    I knew someone would do that, which is why I tried to keep things as simple as possible.

    It's also why I weigh myself first thing in the morning, which one should have to make a small assumtion about and not get hung up on, that is if the topic were to make any progress.

    Just so that everyone understands what is going on, the current theory is:

    It is possible in a 24 hour peroid that a human consumes 1.5 lbs of solids and liquids which gets converted into 2 lbs of fat and waste.

    The assumption here is that the solids and liquids consumed contain "potential energy" or calories and that energy is converted into mass or weight.

    Sounds crazy when I say it, can this be correct?
  16. Oct 3, 2007 #15
    I don't think that is physically possible. The amount of energy required for an energy->mass conversion of half a pound is more than you will eat in your life. You should look at other ways of exchanging mass with the environment.

    For instance, can anyone tell me if there's a way in which a positive mass gain may be made from breathing? (That is, more oxygen is absorbed than is exhaled in waste products). I understand this isn't the case, but I just want to be sure.
  17. Oct 4, 2007 #16
    I have for strickly amusement weighed myself more than once in the morning. Several times I've gained 1/2 a pound in between 30 minute weigh-in's with no consumption or deposits in between.

    I don't know the reason.
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