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Curious about Food and weight

  1. Mar 10, 2017 #1
    simple question,
    please tell me if my understanding is correctly or not

    -------------------

    our body mass can't come form nothing, it have to come from 'food' we eat.

    so,
    If I'm eat 100 gram of food,
    no matter how high calorie that food is, I never gain weight more than 100 gram.

    correct?

    --------------------

    English is not my native language, sorry if I'm wrong in spelling or grammar.
     
  2. jcsd
  3. Mar 10, 2017 #2
    Depends on the caloric density of the food.

    There's about 778 calories per 100 grams of human fat.

    Coconut oil has 862 calories per 100 grams.

    If you assumed a 98% efficiency in surplus caloric conversion, then eating 100 grams of coconut oil could result in gaining 109 grams of fat.

    The answer depends on how efficiently the human body can convert ingested calories into fat - I assume this number is quite high (i.e. close to 1).
     
  4. Mar 10, 2017 #3

    OmCheeto

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    Correct!
     
  5. Mar 10, 2017 #4
    Keep in mind that most foods you eat have considerable water and it has no caloric value. Meat is about 75% water Veggies 90% water.

    Your body must use some energy just to keep going/living. That amount of energy is determined by your basal metabolism for a young male about 1500 cal.. In any given day if your basil metabolism uses 1500 cal. and you consume 2000 cal which could be about 75 grams of protein (600gms meat), 70 grams of fat and 250 grams of carbs 1500 cal off the top is used to run the biochemical machinery leaving 500 cal for activities/work and if you didn't need all of that then whatever is left over will be incorporated into tissue and thus weight gain.
     
  6. Mar 10, 2017 #5

    Evo

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    Wrong, it's the calories that matter, not the weight of the food. Bad Om.
     
  7. Mar 10, 2017 #6

    OmCheeto

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    Excuse me?

    Nowhere do I see mention of pooping. If you eat 100 gram of food, you will weigh 100 gram more.

    Of course, there are 4 years of biology missing from the question, IMHO, that account for the difference in our answers.

    Chitose, Eating 99 grams of high calorie food that don't get pooped out each time you eat 100 grams will make you very fat very fast, and you will probably die at a very young age.
     
  8. Mar 10, 2017 #7

    Evo

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    AHAHAHA! You forgot evaporation through breathing and sweating, how about urination?

    Believe it or not, this is not the first thread we've had about what the OP posted.
     
  9. Mar 10, 2017 #8
    By "gaining weight", it seems fairly obvious that he means gaining body fat - not instantaneous gain in body weight.
     
  10. Mar 10, 2017 #9

    OmCheeto

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    Well, no, I didn't forget them. I just didn't mention them.
    As if I had, I'm sure the conversation would have eventually evolved into "someone" pointing out that trees eat a lot of CO2, and they get really fat.*

    Not really sure of the "caloric content" of CO2 though. hmmmm......
    I believe you.
    [edit: Oh. I didn't realize you were saying that this is the 2nd time the OP has posted the semi-exact same question. My bad.]

    *Of course, they don't exercise much. In a human style, that is.
     
  11. Mar 10, 2017 #10

    OmCheeto

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    Actual Gizmodo article title: Is CO2 Making You Fat?
    dated 2012.03.14

    ps. It mentions nothing of "caloric content".
     
  12. Mar 10, 2017 #11
    If I'm really gain weight more than 100 gram from 100 gram food
    where that extra mass came form?
     
  13. Mar 10, 2017 #12

    Evo

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    You need to learn about the calorie content of food, I suggest that you read this thread and especially the links to the information. The weight of the food is absolutely meaningless.

    https://www.physicsforums.com/threa...-of-a-food-item-measured.616975/#post-3975660

    If that is too difficult for you, perhaps starting off with something simpler might help.

    http://kidshealth.org/en/kids/calorie.html
     
  14. Mar 23, 2017 #13

    rbelli1

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    From water. The energy content of body fat is considerably less than that of pure fat.

    BoB
     
  15. Mar 24, 2017 #14

    russ_watters

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    Yeah, I'm not sure if it was made clear enough:
    So if you eat something dry and fatty, like chips, it will combine with water you drink to contribute more to your weight than its own weight. If you eat veggies with lots of water and few calories, they contribute less than their weight.
     
  16. Apr 10, 2017 #15

    morrobay

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    You have to consider the products in this question : Sure if you eat 100 grams of sugar you are + 100g weight (immediately) . But suppose you take in 100 grams sugar (glucose) in excess of energy requirement. The 6 carbon sugars are converted to two 3 carbon alcohols ( glycerol ) then six fatty acids react with the two glycerols ( condensation reaction , OH from acid H from alcohol) forming two esters (fat) . So the products here are more than initial 100 g: 100g glucose = .55 mole and if all converted to fat ( triglyceride) 885g/mole
    http://chemistry.elmhurst.edu/vchembook/552triglycerides.html
    So the two 3 OH glycerols react with 6 fatty acids to form the esters. Starting with 100g glucose, .55 mole
    How many grams of triglyceride ( 885g/mole) are produced ?
     
    Last edited: Apr 10, 2017
  17. Apr 10, 2017 #16

    morrobay

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    Would that be
    .55 mole glucose x mole ester/ mole glucose x 885g/mole = 490 grams . Then 6 x 490g
     
  18. Apr 12, 2017 #17

    morrobay

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    Correction : 100g sugar (glucose) = .55 mole.
    So .55 mole glucose x 2 moles triglyceride/ 1 mole glucose = 1.1 mole triglyceride x 885 g/mole = 973 g fat
    So the excess 100 g sugar converted to 973g fat
     
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