the Calorie content of protein

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frogbyte
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the Calorie content of protein

Post by frogbyte » Tue Jun 16, 2009 2:37 pm

A Calorie, the measure of energy, is assigned 5 per g of protein. But, rabbit starvation shows us that Calories are not fungible - ie you can't convert protein to fat, and you can't burn protein for energy. So, what does it really mean to have 5 Calories in a gram of protein? Again, Calorie is supposed to be a measure of energy, but you if can't use it for energy, it would seem like the Calorie content should be 0 for protein.

The only thing I can think of it's the Calorie content of protein is based off of the non-essential amino acids, and the equivalent amount of carbs/fats it would take to create those non-essential amino acids? But for essential amino acids, that would be meaningless.

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Post by jeffrerr » Tue Jun 16, 2009 5:59 pm

Not sure about the question, but the caloric content of 1g of protein is 4 not 5!

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Post by Jebus » Tue Jun 16, 2009 8:46 pm

also protein can convert to glucose, if not enough calories are supplied by fat or carbs.

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Post by Jungledoc » Tue Jun 16, 2009 11:56 pm

Remember what a calorie is--a measure of the ability of the combustion of a substance in a calorimeter to raise the temperature of 1 ml of water 1 degree Celsius. Our body does not really burn any food, macronutrient or body component. I don't think it makes much sense to compare a "calorie of protein" with a "calorie of fat".

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Post by Ironman » Wed Jun 17, 2009 1:21 am

A calorie measures heat. 1 grams of protein gives off 4 calories in a blast furnace. Other than that it really doesn't mean anything.

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Post by Jungledoc » Wed Jun 17, 2009 9:23 am

Yeah. That's what I'm saying.

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Post by frogbyte » Wed Jun 17, 2009 12:48 pm

I assume you mean a bomb calorimeter. But surely they're not doing that - that'd be a completely useless metric. Plywood would end up with a lot of Calories by that measure, but you'd get no Caloric food value from it.

There is some evidence on the web ( http://www.caloriecontrol.org/redcalqa.html ) that the FDA set these values. But I can't find any information on the FDA's criteria.

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Post by stuward » Wed Jun 17, 2009 1:33 pm

frogbyte wrote:I assume you mean a bomb calorimeter. But surely they're not doing that - that'd be a completely useless metric. Plywood would end up with a lot of Calories by that measure, but you'd get no Caloric food value from it.

There is some evidence on the web ( http://www.caloriecontrol.org/redcalqa.html ) that the FDA set these values. But I can't find any information on the FDA's criteria.
Plywood does have a lot of calories, however, it's all fibre though so it would just pass through as roughage and net calories would be zero.

Just because a metric is useless doesn't mean that it isn't used.

http://www.evfit.com/calories.htm

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Post by Jungledoc » Wed Jun 17, 2009 2:51 pm

frogbyte wrote:I assume you mean a bomb calorimeter. But surely they're not doing that - that'd be a completely useless metric. Plywood would end up with a lot of Calories by that measure, but you'd get no Caloric food value from it.

There is some evidence on the web ( http://www.caloriecontrol.org/redcalqa.html ) that the FDA set these values. But I can't find any information on the FDA's criteria.
EXACTLY!

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Post by frogbyte » Wed Jun 17, 2009 4:12 pm

According to one FDA page, manufacturer's labels are allowed to deduct insoluble fiber, so its calorie count is 0. That would mean they're not just using the bomb calorimeter method. That evfit article also claims they're using a fudge factor for protein to make it less. Seems like a mistake on the FDA's part not to just make it 0.

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Post by Jungledoc » Wed Jun 17, 2009 9:18 pm

That takes us back to the concept of "net carbs" which (for reasons that I don't understand) always seems to trigger emotional responses.

And yes you can use a calorimeter to figure out the net calories. You test one specimen of a food, then doing something (I don't know what) to separate the fiber from another specimen, then measure the caloric value of the fiber.

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Post by stuward » Thu Jun 18, 2009 7:17 am

If you are going to count calories, protein does matter. Surplus calories are still surplus and a deficit is a deficit. If you want to lose weight, eat less, if you want to gain weight eat more.

That said, I believe that what you eat makes more difference than how much you eat. Your body knows how much food it needs and will adjust your activity to match your intake, and your apetite to match your activity automatically. (Big word of the day: "homeostatis".) That means that calorie counting doesn't work very well.

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Post by wilburburns » Thu Jun 18, 2009 9:10 am

stuward wrote: That said, I believe that what you eat makes more difference than how much you eat. Your body knows how much food it needs and will adjust your activity to match your intake, and your apetite to match your activity automatically. (Big word of the day: "homeostatis".) That means that calorie counting doesn't work very well.
Wow, This statement truly iintrigues me. Why would you say that.

I may be taking this completely out of context, but this is how I understood the above statement and relate it to a Fictitious Person.

Person1:
I am an active person, therefore, I can eat all I want, because my body will tell me to stop, or I my body will just "USE" my surplus food intake....
From my experience, this person will eventually get FAT or overweight because they get used to eating Tons of food, but eventually aren't as active as they once were.


Person 2:
I am a lazy person and won't eat that much, because I don't need the food ana my body will tell me when to stop eating.
This person may already be overweight, because they they just don't do anything to burn the calories they are eating.

I may be just oversimplifying your statement above, but relying on the body to either tell me to stop eating or to be more active is not always (rarely is) a good Weight loss plan. It can work for a while to maintain though.

Many people (myself especially) have problems with eating to fast, therefore by the time my body tells me I am full, I have really been full for a while, but kept eating. This tends to make me tired and not want to do anything, which truly contradicts your statement, Because overeating then sitting on my Butt is a sure fire way to get FAT..

Cliff

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Post by frogbyte » Thu Jun 18, 2009 10:48 am

But the issue of rabbit starvation clearly shows that surplus Calories are meaningless if the Calories are protein, because it costs more to convert protein to energy than you get out of the energy.

As far as weight management goes, I'd mention that 2 months ago I stopped eating bread and drinking milk at lunch. To make up the difference I increased the amount of ham I ate to 1/2 lb (an increase of about the same amount of Calories from the milk/bread) but have lost 6 pounds of body mass since then. (I've never counted Calories on a regular basis, but I'm extremely consistent about the volume of food I eat, and the types of foods.) Presumably almost all of the mass was fat, since I've continued to get stronger in the same time span.

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Post by stuward » Thu Jun 18, 2009 11:24 am

wilburburns wrote:...I may be just oversimplifying your statement above, but relying on the body to either tell me to stop eating or to be more active is not always (rarely is) a good Weight loss plan. It can work for a while to maintain though.
...Cliff
That's why "what" you eat is so important. The problem is the modern diet. Refined carbs, vegetable oil, MSG, animals raised in unnatural conditions, high calorie drinks, etc all contribute to a situation where a person's body is so confused and abused that it can't interpret the signals properly any more.

By switching to a diet that is in tune with our evelutionary requirements, your body can adapt on its own. Focus on wild meat or meat raised in natural conditions, and other "real" foods. Minimize processed foods. and those food like substances mentioned earlier. If you eat healthy food, you will become healthier and your weight will normalize.

Keep in mind that refined carbs and MSG stimulate the appetite. Including these in your diet will automatically cause you to become fat. From a fat loss point of view, eliminating these, along with minimizing high calorie drinks, is essential. Getting your O6/O3 fat ratio into balance is essential for your heart. The best way to do that is minimze vegetable oils and eat fish and wild meat regularily.

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