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how do "fast" and "slow" metabolisms work?

D

dpopiz

Diamond Member
- ok, so assume two people eat 2000Cal per day and do EXACTLY the same amount of work (physical stuff + body heat etc)
- jeff burns 2000Cal per day
- kevin burns 1500Cal perday

- all 2000Cal of the 2000Cal that jeff eats goes into work
- only 1500Cal of the 2000Cal that kevin eats goes into work

so the other 500Cal that kevin eats goes into storage (fat)


--->But how is that possible? Energy is conserved, so how can 1500Cal do the same amount of work as 2000Cal?
 
One metabolism may be more efficient than the other (like gas economy between two cars of equal weight and power, and yet one does better with the same amount of gas). But of course other things come into play like age (a child's metabolism is more active, to support growth), and muscle mass.

So to answer, 1500 is not doing the same as 2000. The 2000 is doing what the 1500 is doing, plus some other things.
 
If your metabolism is different you're technically not doing the same amount of work. I haven't really hit on metabolism in my physiology classes but I'm sure it has to do with homeostasis of the body's internal environment and whatnot. Muscle mass also increases the amount of calories you burn while you're just sitting on your butt. Maybe jeff has 20lbs of muscle on kevin. *shrugs*
 
Originally posted by: Zim Hosein
You'll receive more help here: http://www.geekfitness.com 🙂
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Thanks for wh0ring out the forum 😛

You say they do 'exactly' the same amount of work. By this I take it both run xxx distance etc right? Not use up the 'same' amount of calories? Because if they use up the same amount of calories the metabolism doesn't factor in to it. It will only determine the 'time' to use up that many calories etc.

If you run 10km and an 'experience' runner runs 10km I can sure as hell bet that guy is going to use calories then you in doing so. Muscle effciency, cardio efficiency etc.

Metabolism is the rate in which you use calories up. If you use the same amount of calories up then it doesn't matter either way.

The whole point of your metabolism is to increase it by doing exercise/ weights with big muscle groups.

w is that possible? Energy is conserved, so how can 1500Cal do the same amount of work as 2000Cal?
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Short answer: muscle/ cardio effciency. Better runners/ swimmers can a further distance with less calories expended

Koing
 
Hmm. Fascinating question. I don't really know the exact answer.

But I think AbAbber2k is right. If their metabolisms are different, then that is the difference.

Hmm. That doesen't really answer his question at all though.

So... what causes higher or lower metabolisms, and how does that relate to work produced.. either in your body or externally?

Is it simple efficiency? What a person has been eating, their general state of health, etc? I like Skoorb's car example..

I need a tuneup. 🙁

😀
 
Lower metabolism is 'generally' lower active lifestyle meaning less exercise/ cardio/ muscle mass. BUT you get lazy people that are really thin who eat lots of junk food and calorie rich food. This means they have a higher metabolism but GENERALLY it will slow down as they hit 25-30 with no exercise and they will too end up with a gut.

Training large muscle groups will help you to have a higher metabolism so that means to squat and deadlifts to a full ROM. Squats or DL to half ass movement isn't good either 😛. As soon as you train your metabolism will pick up and the more muscle mass you have your metabolism is increased also. Muscle needs to be sustained so you need to eat more compenstate.

How does it relate to work? It doesn't. A person with a lower metabolism could run faster/ be stronger etc then a person with a high metabolsim who did no training. If they both do training it wouldn't matter for that 'event' they did. Your metabolism has no impact for 'work produced' as the time is too short. Maybe if the event was for days and you both couldn't eat to do this event but then I'm sure the people would have enough energy reserves to do it anyway 😛

Koing
 
Originally posted by: Koing
Lower metabolism is 'generally' lower active lifestyle meaning less exercise/ cardio/ muscle mass. BUT you get lazy people that are really thin who eat lots of junk food and calorie rich food. This means they have a higher metabolism but GENERALLY it will slow down as they hit 25-30 with no exercise and they will too end up with a gut.

Training large muscle groups will help you to have a higher metabolism so that means to squat and deadlifts to a full ROM. Squats or DL to half ass movement isn't good either 😛. As soon as you train your metabolism will pick up and the more muscle mass you have your metabolism is increased also. Muscle needs to be sustained so you need to eat more compenstate.

How does it relate to work? It doesn't. A person with a lower metabolism could run faster/ be stronger etc then a person with a high metabolsim who did no training. If they both do training it wouldn't matter for that 'event' they did. Your metabolism has no impact for 'work produced' as the time is too short. Maybe if the event was for days and you both couldn't eat to do this event but then I'm sure the people would have enough energy reserves to do it anyway 😛

Koing
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Ahh. Yes, I see.. that makes sense.

Hmm.. what about internal body workings, though? It takes quite a bit of energy to keep your body at 98.6ºF.

What does metabolism effect, then? Surely someone that can eat all that junk food and not gain a pound, vs. someone that isn't like that... where is all that extra energy going? Since it isn't being turned into fat.. it's not just being "thrown away", is it? If not, it has to be burned... 98.6ºF is only average, so do people with "high metabolism" exhibit higher body temperatures, or what?
 
Metabolism effects the rate in which you can use calories up. Some have faster and some have slower. So when you eat say a 500 calorie meal it will be the time your body uses up those calories without exercising. Like athletes who can eat through 3000 calories and not put weight on even if you take in to the account calories expended during their training. The times that they are 'resting' is where their high metabolism separates them from lower metabolisms. Lower you will most definately put fat on.

Hmmm...where is all that energy going to? Good point I'll ask my coach.

Perfect example is the World Hot Dog eating Champion. Small 5"7 Japenese guy. He can kill what? 30-40 in whatever time? That MUST be a serious amount of calories there.

Koing
 
Ok, first of all, let's assume Jeff and Kevin are both sedentary for the test. Neither does anything but sit on a couch all day. Second, we can't assume Body Heat is the same because heat produced by the body is a function of metabolism. Soooo if their metabolism is different their heat production will be different.

From Exercise Physiology: Human Bioenergetics and Its Applications. By Brooks, Fahey, Baldwin.
"Metabolism can be defined as the sum total of processes occurring in a living organism. Because heat is produced by these processes, the metabolic rate is indicated by the rate of heat productoin."

Metabolic rate is measured as energy expenditure over time (kcal/min) - Human Physiology, 5th Edition, Sherwood

So where do the extra 500kcal of energy go to? Thyroid Hormone release and Epinephrine (adrenaline) both effect BMR. I can't say exactly how, but how much you eat changes your metabolism. If you ever follow/laugh at diet trends, you should know that the less you eat, the lower your metabolism gets. Basically, your body senses that food/energy is becoming more scarce so it "slows down" to conserve energy. Conversly, if you increase food intake, the body responds by increasing metabolism.

So to answer the question "How does one person have a 500kcal excess of energy that is stored as fat?" all we can really say is, the internal physiology of each subject is different. I can't be sure, but I would say if you took two people, with the same sex, height, weight and %bodyfat who ate the exact same amount of food and did the exact same amount of work, their BMRs would be next to identical. Basically your lifestyle/stage of development controls your BMR. I've never heard of people having gene's that allow their hemoglobin to carry more O2 or to create more energy from ATP (since they're chemical reactions I think it'd be impossible).

Apologies if this restates anything someone else posted, I wrote it while watching over dinner, doing laundry and thumbing through my physiology text books.
 
Good answer and a more technical one AbAbber2k 🙂

Koing
 
Originally posted by: AbAbber2k
Ok, first of all, let's assume Jeff and Kevin are both sedentary for the test. Neither does anything but sit on a couch all day. Second, we can't assume Body Heat is the same because heat produced by the body is a function of metabolism. Soooo if their metabolism is different their heat production will be different.

From Exercise Physiology: Human Bioenergetics and Its Applications. By Brooks, Fahey, Baldwin.
"Metabolism can be defined as the sum total of processes occurring in a living organism. Because heat is produced by these processes, the metabolic rate is indicated by the rate of heat productoin."

Metabolic rate is measured as energy expenditure over time (kcal/min) - Human Physiology, 5th Edition, Sherwood

So where do the extra 500kcal of energy go to? Thyroid Hormone release and Epinephrine (adrenaline) both effect BMR. I can't say exactly how, but how much you eat changes your metabolism. If you ever follow/laugh at diet trends, you should know that the less you eat, the lower your metabolism gets. Basically, your body senses that food/energy is becoming more scarce so it "slows down" to conserve energy. Conversly, if you increase food intake, the body responds by increasing metabolism.

So to answer the question "How does one person have a 500kcal excess of energy that is stored as fat?" all we can really say is, the internal physiology of each subject is different. I can't be sure, but I would say if you took two people, with the same sex, height, weight and %bodyfat who ate the exact same amount of food and did the exact same amount of work, their BMRs would be next to identical. Basically your lifestyle/stage of development controls your BMR. I've never heard of people having gene's that allow their hemoglobin to carry more O2 or to create more energy from ATP (since they're chemical reactions I think it'd be impossible).

Apologies if this restates anything someone else posted, I wrote it while watching over dinner, doing laundry and thumbing through my physiology text books.
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Hmm....

But what about the phenomenon where 1 person can eat seemingly unending ammounts of high calorie foods, and another cannot without gaining weight?

That's exactly how my brother and I am. He's a stick and can eat anything he wants. I'm also pretty thin, but I have to watch what I eat or I will gain weight fast. His lifestyle isn't THAT different from mine, we live with eachother.. do the same basic things.... although our diets are different. He tends to eat smaller meals more often, and I eat bigger meals less frequently. Is it all just in our heads? If we actually counted all the calories, would the person who can seemingly eat unending ammounts of food actually be consuming less?

There has to be more to the equation.

So... assuming all else is equal, IF person A has a higher metabolism than person B, their body temperature would also have to be higher?

Our body certainly has the capability to make our body temperatures higher, but there is a narrow comfort range.. So I dunno. Would a few tenths of a degree higher or lower be a significant metabolism change?
 
To answer your question Eli YES.

Raising temperature IS NOT EASY even by 1*C.

Your body and genes are different. He oblivous a mutant got the high metabolism and you didn't. Hey does he have claws coming out of the top of his wrists that are seemingly industructable? 😛

But you'd have to 'actually' count how many calories you both ate 'exactly' to work it out.

He has smaller meals which is BETTER for you then just 3 big ones.

Koing
 
I think I remember from my Human Physiology class that a 1 degree increase in temperature raises your metabolism by 10%. So, if you have one person with their normal temp being 1 degree lower than normal, and another being 1 degree higher than normal, their metabolic rates would be approximately 20% different. That can turn out to be quite a substantial amount of calories.
 
I would say it's likely "all in your head." At least for the most part. Part of it is probably how you see each other's diets. You say that he east lots of small meals while you eat a few large meals, the end result is it seems like he's ALWAYS eating therefor he's eating more. I was the same way as your brother (still am actually). My family always thought I had an insatiable appetite because I'd eat very often, but in smaller quantities. It wasn't until I went on a bulking diet that my family realized I wasn't really eating much. It's also been suggested that eating several small meals a day, instead of say three large meals, can increase your metabolism.
 
There are a few things can contribute to this

Some people are more fidgety. When they sit still, they sit less still than people with "slower" metabolisms. I read a study about this somewhere a while back (can't find it now) and there seemed to be something to it.

Brown fat - brown fat is sort of like a car engine stuck in neutral. Different people could conceivably have different amounts of it, those with more will burn calories faster.

overal fitness - muscles tend to burn more calories than fat (except brown fat), so the higher percent weight of muscle, the higher the basal metabolism.

In colder climes, thinner people will burn more calories that larger people, due to the surface area/volume ratio being higher.
 
Originally posted by: AbAbber2k
I would say it's likely "all in your head." At least for the most part. Part of it is probably how you see each other's diets. You say that he east lots of small meals while you eat a few large meals, the end result is it seems like he's ALWAYS eating therefor he's eating more. I was the same way as your brother (still am actually). My family always thought I had an insatiable appetite because I'd eat very often, but in smaller quantities. It wasn't until I went on a bulking diet that my family realized I wasn't really eating much. It's also been suggested that eating several small meals a day, instead of say three large meals, can increase your metabolism.
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Hmm... interesting.

So, "fast" or "slow" metabolism, at least in the same context as the example using my brother and I, is more or less just a buzz phrase...

 
"Fast metabolism" is manifested as higher body temp, yes. If you're on a diet, you can track the decline in metabolism over time by keeping a log of your waking morning temperature. Most people are normally *not* 98.6 at that time of the day, if you're much below 97 then you're getting into low territory IIRC.

Muscle tissue is the primary heat generator in the body. If you want to up your BMR, your best option is putting some quality inches on your ass, thighs and chest.


Originally posted by: AbAbber2k
If you ever follow/laugh at diet trends, you should know that the less you eat, the lower your metabolism gets. Basically, your body senses that food/energy is becoming more scarce so it "slows down" to conserve energy. Conversly, if you increase food intake, the body responds by increasing metabolism.
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Your brain keeps tabs on bodyfat levels over the longterm with leptin and adjusts accordingly. If it's getting too low, T3 starts tanking and appetite goes crazy. Getting ripped isn't what your body has in mind for survivability, and it's not going out without a fight, meh

 
Well, they're definitly buzz-words in some instances, most of the differences are occuring on the cellular level though. Like I said, various hormones affect your BMR. It's entirely possible that someone's genetic makeup could make them naturally produce more epinephrine or... whatever the other hormone I mentioned was... thus increasing their BMR for "no apparent reason." I guess in my other post I kind of downplayed the role that genetics play. They're definitly there, but I was trying to emphasis how many different things can affect your BMR that are a little more "tangible" than genetics.
 
I really don't need to worry about my metabolism. My metabolism level is really high, I mean the maximum one. I'm 21 and still thin as well. I thought I would lose my metabolism when I become older but I guess I'm wrong. 😛
 
Originally posted by: jewno
I really don't need to worry about my metabolism. My metabolism level is really high, I mean the maximum one. I'm 21 and still thin as well. I thought I would lose my metabolism when I become older but I guess I'm wrong. 😛
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a) you ain't old yet

b) it's not the age that gets you, it's the lifestyle change of getting married & staying home and working 8-10 hrs. a day planted at a desk 😛
 
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