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Dieting and metabolism

  1. Nov 16, 2005 #1
    Hey guys;

    I've always heard things similar to that instead of eating three meals a day, you should spread the same amount of food over say five meals a day. Eat smaller portions, but more often.

    I don't understand why (if) this works. If you keep eating small amounts all day long, you will keep your body producing insulin to lower your blood sugar levels. If you keep producing insulin, you stimulate the anabolic parts of metabolism (such as increased glycogen synthesis, increased protein synthesis, increased glycolysis, increased protein synthesis, and increased fatty acid synthesis.)

    So bascially, if you eat all those portions all day, your body will constantly be building up its stores. How can that help you lose weight?

    Thank you!
  2. jcsd
  3. Nov 16, 2005 #2

    Im no expert, but what i think/have heard is that by eating little and often, you maintain/increase your metabolic rate (i think this is the rate at which your body burns energy)

    Another way to look at it is, if say you only had one meal a day, your body would react by absorbing all the energy it could, in case it was another x hours before the next meal.

    So i think by having more smaller meals, your body will not "worry" about not getting enough nutrition, and so will not feel like it needs to store absolutely everything you eat.

    And also, i think more/often will mean a more balanced sugar level, which is supposed to be a good thing.

    I find snacking on fruit in between meal, stops you becoming "overly hungry" when the next meal time comes. This helps because i believe it takes say 20 minutes for your body to tell your brain that you are full, so in theory, you could be eating extra food for this "20 mins" which you didnt really need.

    another tip is to drink plenty of water, as this does help to make you feel more full when you do eat, and i think the "hunger" cravings sometimes are for fluids.

    Like i say, im not an expert, but i believe this to be correct.

    Hope this helps

  4. Nov 16, 2005 #3
    That's cool. I'm not looking to lose weight, I'm in med school biochemistry right now, and was just trying to reason out what I'm learning.

    We also learned that white adipose tissue secrets a chemical called Leptin that makes you not feel hunger. I wonder why we can't synthesize that and take it orally or by injection?
  5. Nov 16, 2005 #4
    Leptin huh, well i guess if it can be sold, it will be on the way hehe
  6. Nov 16, 2005 #5


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    Because it has effects on neural systems other than just satiety, such as reproduction (the mechanism isn't known yet). As with any hormone, you also have to keep in mind the homeostatic mechanisms involved in its regulation. If you give more of a hormone via injection or pills, etc., you shut down endogenous release due to negative feedback. Leptin has only been fairly recently discovered...perhaps only 10 years ago, which in endocrinology is quite new. There is also a new appetite regulatory hormone just announced as having been discovered, and it has been given the name obestatin. The problem with something that new is that we often find hormones influence many systems in the body, not just the one system being studied that led to its discovery.
  7. Nov 16, 2005 #6


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    I was going to ask about those hormones (leptin, obestatin) - are they fat or water soluble?
  8. Nov 16, 2005 #7
    So what about that OP? ;-)
  9. Nov 16, 2005 #8


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    I must emphasize that I know nothing.

    I'm not sure whether eating often is a cause or effect of being healthy. The only people I know who eat like this are very active people. One is a weight lifter, one plays hockey, and one is just a twichy guy who likes stimulants. I'm a skinny guy who eats maybe once every 7 hours. You'll just as easily find a fat guy who eats every 7 hours.
    It probably has more to do with activity than anything else.
  10. Nov 16, 2005 #9
    i highly doubt it would take that long! wow 20 minutes? but i usually scarf down my dinner in about 5 minutes when i have tons to homework to finish and i feel almost full immediately afterwards. (before i was starving too) so it couldn't take 20 minutes right?
  11. Nov 17, 2005 #10
    Like i said, i am not an expert, but it is something i have heard a few times from different people. Perhaps it is incorrect, or maybe the time is shorter, i really couldnt say.
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