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View Full Version : excess calories of protein to promote weight loss? biochemical not epidemiological?



laxplayer39
11-17-2004, 01:24 PM
update edit:still stuck on this a bit - if anyone wants to be my consultant on this you guys can get at me email sp375@cornell.edu or aim: moongbean99

sorta just want to bounce some ideas of someone with some knowledge about this - like theory and whatnot.
...
Hey guys,

This was a question I was posed to answer by my nutrition professor. His question is a pretty interesting one, and since I am facisinated by nutrition and the like (I am in college right now) I was wondering how you guys here would respond to the challenge. Personally, I went from 220lbs to 165lbs by virtue of eating a lot more protein and a lot less carbs - maybe not as strict as Atkins, but still pretty good and a lot of excersise (lifting mainly, lacrosse and basketball for cardio).

Why does an individual eating above Caloric needs in which those
Calories are primarily derived from protein sources still lose weight? In other
words, not all Calories are the same, or are they? And where do the Calories "go".

He doesnt want anecdotal data, albeit important, not epidemiological data, albeit a little more important, but the "why" behind all this....if it's known. There are the Laws of Thermodynamics, three in all....the first in question here.

accuFLEX
11-17-2004, 02:41 PM
How long did it take you to go from 220lbs to 165lbs?
I have also seen that I lose more weight when I eat a lot more protein.

Severed Ties
11-17-2004, 05:22 PM
Protein is more thermogenic meaning your body must expend more energy to digest it than fat or carbs. Protein is also the most difficult macronutrient to store as fat.

ST

laxplayer39
11-17-2004, 06:30 PM
took me about a good 6 months to a year really ... dont fool yourself though I still have some lower abdominal fat which really sucks but im beginning to think of it as excess skin as opposed to fat.

well i know protein has a thermogenic effect - i was looking more for a scientific platform from which to answer the question posed to me by my prof.

thanks guys
sunil

Rex
11-18-2004, 12:00 PM
Protein is more thermogenic meaning your body must expend more energy to digest it than fat or carbs. Protein is also the most difficult macronutrient to store as fat.

ST

:withstupi

The answer given above is ace. That's the exact answer to your question. Just elaborate on the principals. The so called excess energy really isn't excess. It's needed to metabolize the protein.

A true calorie excess will always be stored as fat.

shansen008
11-18-2004, 12:16 PM
Start with a basic number of calories needed for digestion/24 hours, based on the average Americans diet (which is horrible btw). That number increases greatly when your macronutrients are shifted toward a large amount of protein because your body must expend much more energy to convert the protein into usable forms of energy for resperation.

Additionally if you are lifting properly (read heavy, heh), much protein is used to rebuild muscle fiber and doesnt actually get "burned" so to speak. Remember the laws of physics, energy is not created nor destroyed, but merely changes forms. Dont look at a calorie as a piece of food, but as a unit of energy.

laxplayer39
11-18-2004, 05:52 PM
dude okay this is making a bit more sense

so i would also have to stress the fact that this can only work given that the person is doing some form of anaerobic activitty (lifting weights etc) because then those extra cals of protein wouldn't be burned or stored as fat, but turned into muscle?

deadheadted
11-19-2004, 03:50 PM
In terms of the first law of thermodynamics, think of it this way: No energy is being "lost" or "destroyed" - it's just that your body needs to work harder (expend more calories) to convert protein into viable fuel versus fat or carbohydrates. Thus protein has a higher thermic effect.

Does your body have to work very hard to convert fat into fat? No. Does it have to work hard to convert a bunch of amino acids into energy? Yes. That's where the calories "go" - the body uses them in digestion of the protein where it wouldn't normally use that many for carbs or fat.

Shark
11-19-2004, 03:57 PM
so i would also have to stress the fact that this can only work given that the person is doing some form of anaerobic activitty (lifting weights etc) because then those extra cals of protein wouldn't be burned or stored as fat, but turned into muscle?

No, becasue this isn't true. However, it would make it substantially easier for a person doing some sort of exercise that involves a lot of tissue rebuilding. Here's the thing. If you need 2k cals a day as an average person on an average diet and you switch to 2100 cals almost all proteing and EFA's, you're still going to lose weight. Take the same person, switch their diet, then add 3xa week weight lifting. Now some of that protein is going towards rebuilding muscle tissue and is thus not part of the 2100 they are eating. They lose more weight.

laxplayer39
11-19-2004, 10:47 PM
yah but how do we know the body does this? are there studies to bakc this up like in comparison to if someone ate only calories from carbs and/or fat? that could be arugued too

laxplayer39
11-22-2004, 11:06 PM
still stuck on this a bit - if anyone wants to be my consultant on this you guys can get at me email sp375@cornell.edu or aim: moongbean99

sorta just want to bounce some ideas of someone with some knowledge about this - like theory and whatnot.