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Even though we have enough calorie for day, why are we still hungry?

  1. Jun 6, 2012 #1
    Hello, Chitose here.
    It's been ages since last time I post my question here.

    ................

    As topic said, even though we have enough calorie for that day on, why are we still able to hungry?

    I try myself, eat chocolate bar with very high calorie, even potato snack with high calorie.
    and calculate that I surely enough calorie for day.

    yet... I'm still hungry after six or seven hour pass. why?

    Dose our body still yearn to have something ran trough digest system no matter what?





    or..... this only happen to me???? OMG =[]=

    ..............................

    English is not my native language, sorry If I'm wrong in spelling or gamma.
     
  2. jcsd
  3. Jun 6, 2012 #2
    Enough calories to do what? To live? To store energy for some specific length of time? What length?
     
  4. Jun 7, 2012 #3

    Monique

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    1) What is hunger? Most likely you're just craving which is something different.
    2) Calories are not the only nutritional requirement. Chocolate bars and potato chips are not exactly proper foods to sustain a diet on.
     
  5. Jun 7, 2012 #4
    Hi,

    It does'nt just happen to you chitose. It happens to me as well. I think that even though we may have eaten enough (or more than enough which is often the case) like a chocolate bar (which theoretically should be sufficient for our daily energy requirements) our bodies still crave more because it wants something different to taste. Also it probably has to do something with our stomachs feeling full. If we don't feel full we do consume more food even if its not required.

    Regards
     
  6. Jun 7, 2012 #5

    Ryan_m_b

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    As monique says you are probably hungry for something else. Regulate your meals better, eat three balanced meals a day at regular times and allow yourself minimal snacks (and try to make the snacks as healthy as possible, next time you reach for chocolate grab an apple instead). You'll be healthier for it and should stop feeling so hungry.
     
  7. Jun 7, 2012 #6

    bobze

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    Hi Chitose, that is a good question.

    The answer is because are bodies aren't that smart. The brain doesn't sit down and count up calories and say "well chap, looks like your good for the day". If that were the case, we wouldn't have such a problem with obesity would we :biggrin:


    To answer your question through, food volume has a lot to do with signaling satiety in animals (including humans). For a good discussion see;

    G.N.M. Norton, A.S. Anderson, M.M. Hetherington, Volume and variety: Relative effects on food intake, Physiology & Behavior, Volume 87, Issue 4, 15 April 2006, Pages 714-722, ISSN 0031-9384, 10.1016/j.physbeh.2006.01.010.
    (http://www.sciencedirect.com/science/article/pii/S0031938406000345)

    Leptin a hormone which tells the body "you're full" is controlled by a variety of mechanisms, many of which we are still understanding.

    The problem for us in modern "western" societies is we have access to a lot of foods which have a very rich energy density, but can be low volume. Fats are a great example, eating a gram of fat is about 9 calories. A small (volume wise) meal high in fat may leave you feeling hungry still, even though it has more energy than an equivalent meal of larger volume.

    That is why nutritionists have been moving to the eat more meals, that are smaller, throughout the day theme. Because having a constant volume going through you (even better if it is lower energy density foods) will leave you feeling full. The over all effect if you pick your food right, is a reduction of calories and weight loss even though you 'feel' full!

    Hope that helps
     
  8. Jun 7, 2012 #7

    Monique

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    Seriously? As said: our body doesn't live on calories but on nutrients. Even fruitflies know what they need, they rather eat something that they don't like when they are deficient in that nutrient than something that they like.

    I have some notes that would point to more detailed publications that show the point of nutrient balancing in the fruitfly, but here's already one: Nutrient Balancing in Drosophila.
     
  9. Jun 7, 2012 #8

    bobze

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    That's true Monique. I don't think I said anything that disagrees with that (did I?). In deed our bodies do live on nutrients and not calories, which is why say--a diet of liquid bread (beer!) won't get it done. Its also important to remember that hunger (like the OP was talking about--and what I said seems to be largely a feeling related to volume) isn't the same thing as a food craving. Cravings are specific and in that regard you could say our bodies are smart (classic example of people with porphyria craving "bloody" meats→ for heme, or maybe somebody feeling blue craving chocolate→ for endorphine release). Cravings also happen for emotional reasons.

    Like I pointed out to the OP the feeling of hunger seems to be largely regulated by volume taken in to the GI system (which actually makes sense if you think about the enteric nervous system--chalked full of stretch receptors) and not so much about calories (what the OP was asking about).

    Edit with an additional note: That isn't to say that specific nutrients and/or energy levels aren't important in regulation of the feeling of hunger. That's what I put the intro link to leptin for--for the OP. Leptin plays an important role in the feeling of hunger as well (acting on the lateral area nuclei of the hypothalamus to inhibit the feeling of hunger and conversely stimulating the ventromedial nuclei of the hypothalamus causing satiety)--but the exact control of leptin (and other adiponectins) release from adipocytes is still being worked out. It appears in part to be neurohormonally controlled as well as by the metabolic actions going on in adipocytes (though this isn't a perfect correlate because you can have leptin production w/ increased adipocyte activity and still feel hunger).
     
    Last edited: Jun 7, 2012
  10. Jun 7, 2012 #9

    Monique

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    Ok, thanks for the clarification. The statement that bothered me was that we wouldn't have obesity if the body knew how many calories it consumed, but clearly the bodies is not satisfied with calories alone (and you agree).

    Then I still wonder what hunger really means, I've seen people binge-eating after dinner with the claim "they're still hungry". To me that's not hunger.
     
  11. Jun 7, 2012 #10

    bobze

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    Oh I see, yeah I did write that rather confusingly. Brain wasn't all the way on yet will be my defense :wink:


    I don't know (not that I think anyone does) what hunger really means. That's a damn good question though. I think that probably delves into the whole qualia thing. Certainly underlying a feeling of hunger there is a biological phenomena going on--but how our brain interprets that is another beast all together (for people with way more interest in neuroscience than I, lol).

    That sounds like some good research though (on the binge eating thing). Binge eating disorder is characterized by negative feelings toward food (without purging/exercise--least it be bulimia), while compulsive eating disorder is associated with a positive feeling toward food. It would be interesting to know if these compulsions and binges toward food munching are spurred by the same neurohormonal basis as someone starving that 'feels' hunger. I'd agree that really doesn't seem like hunger, but purely from a logical point of view maybe a malfunction of those neurohormonal systems already in place (though I've no idea whether that is true or not, it would just seem to make sense--but common sense has a tendency to bite us in the *** :tongue2:). No time to look in to it now, do you know if there is any research in to that?
     
  12. Jun 7, 2012 #11
    Thanks for raising the question Monique, I never asked myself that

    It's a good question to ask oneself, "Am I actually hungry?"


    The comment "our body doesn't live on calories but on nutrients." is really well said!.
     
  13. Jun 7, 2012 #12
    I see, even hunger feeling is various form person to person. still no specific way to measure it in reasonable way.

    Calorie is like Gasoline, the harder we work, the more we want...
    nutrients is like motor oil, need to maintain moving parts...

    without any of those two... I'm doom.
     
  14. Jun 8, 2012 #13
    I agree with this.

    Ideally, brain should know about excess calories/nutrients stored in body and instruct digestive system to process food selectively only to get what is (and as much) required and pass on rest without processing. But we don't live in ideal world :)
     
  15. Jun 8, 2012 #14

    Monique

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    Well, I know for a fact that excess cholesterol is secreted by the liver into the intestine. Excess of water-soluble nutrients are excreted through the kidneys. There will be examples where the body fails, but overall I think our body is a well-adjusted system.
     
  16. Jun 8, 2012 #15
    I agree, it's pretty impressive.


    Even looks after energy storage and stuff.

    In addition to the above point, why would the body "count calories" and say "Well chap. looks like you're good for today."? And in what sense does it not? If I eat too much I gain weight, in the form of energy storage. Waste not,...the next part is up to you.
     
  17. Jun 8, 2012 #16

    bobze

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    You guys are thinking about the word smart too much I think. I didn't literally mean the body is "smart" or "not-smart" as in it thinks things through. I meant that it is constrained by the evolutionary limitations put upon it.

    In an evolutionary sense, sure calorie storage is a great idea--That is what the body evolved to do, because in 10,000 BC you might get a load of food today, but not get another solid meal for a day and half (long after your glycogen stores have been depleted--that fat suddenly becomes life saving).

    The problems are from a modern world with food surplus for most people in the "west" and diets rich in things like fat. The body still lives by the evolutionary constraint of "store, store, store"--It isn't "smart" enough to say, "well you are getting plenty of food everyday, we don't need to turn all this excess into fatty acids and short of you hitting the lottery, buying a small plane and then wrecking it in some remote location, we're not likely to need these fat stores". The consequence of which is adverse health effects.

    @Monique. I agree the body is well adjusted for what it was meant to do in the environment it evolved in. I'd say the caveat is though, technological evolution (mass food production etc) has greatly lapped biological evolution. There are problems abound with our biology because of the mismatch in our current environment and the "original" environment. Cholesterol is a great example. Sure the body can secrete it, it just sucks at it. Take a random sampling of LDL from the US population and the liver's ability to cope with excess cholesterol doesn't look that impressive. I know a couple of GI docs that make a cool 400K+ a year simply because the liver isn't that great at cholesterol homeostasis in our modern world (they do nothin but gallstones!). Likewise I'm sure the pharmaceutical companies and their blockbuster (statins) would agree that liver isn't well equipped for modern diets :)

    I agree overall though. Our bodies are fairly well adjusted systems because evolution spent millions of years flushing the ones with poor fitness.
     
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