Fitness Minutes: (168,149)
15,149 1/31/09 10:43 P
Wow, I don't think I've ever seen so many different theories about how your body works in one thread here at SP before, lol.
Basically, what happens to the protein you eat depends on what else you eat, and how much of it--not on some numerical limit on how much protein your body can handle.
Technically speaking, your body doesn't "burn" protein, glucose, OR fat as energy. The energy your cells actually use comes from breaking the chemical bonds of a molecule called ATP, which happens during something known as the "Krebs cycle" that takes place at the cellular level, in the mitochondria of your cells. Your body can use all 3 dietary macronutrients, fat, protein, and carbohyrdates, to generate ATP molecules, so it really doesn't make much practical sense to think in terms of whether your body turns protein into glucose, or into fat, etc.
In terms of weight loss, what matters is whether you're eating more or less than enough to satisy your body's energy requirements, as measured in "calories." When you eat more than your body can use either to generate ATP when your cells need immediate energy, or to restock the energy reserves stored as glycogen in your muscle cells and liver, then this excess energy will be stored as body fat. It will get taken out of storage when there is not enough "stuff" to make ATP out of floating around in your blood stream following the process of digesting your last meal.
As always, this stuff isn't really as simple as just doing the math of calories in versus calories out. Your body is very efficient, and does prefer to get what it needs from the nutrients best suited to provide it. It likes, for example, to "spare" dietary protein from being used to generate ATP for immediate energy needs, and use the amino acids in it instead for repairing and replacing various body tissues and other such purposes. It can do this if you're eating enough carbs and fat to meet your immediate energy needs. But if you eat a lot of protein, and not enough carbs and fat, it will use that protein to make ATP. If you don't eat enough period, your body will actually break down muscle and organ tissue so it can turn the protein in them into ATP for your immediate energy needs. That's why people lose muscle as well as fat when they are dieting. Likewise, your body has no way to store dietary protein as protein for future use (other than a very small pool of amino acids it keeps on hand), so the protein you eat either gets used right away, or it gets broken down and reassembled as fat. This is one of the reasons exercise is so important--it forces your body to keep repairing your muscles because you need them, instead of just letting them get broken down and turned into ATP.
Here's a relatively non-technical explanation of how this all works:
"All your life, you have just been waiting for this moment to arise." (Lennon & McCartney, "Blackbird")
1/31/09 9:44 A
Protein turning into sugars or fats would pretty metabolically hard and convoluted, and that's not how the body operates. 120 g of protein really doesn't seem like that much to me. I think you're ok. Remember, only 4 calories for every gram of protein as opposed to 9 per gram of fat.
Chemist by training.... analytical biophysical surface chemist by specialized training.
"It's all how you look at it." -Tracy Lawrence.
"No day, no night, no moment can hold me back from trying." -Enya
Excess protein can be turned into glucose via a process known as gluconeogenesis. However, it only usually occurs when dietry sources of glucose are not available or the liver has exhausted its glycogen stores (glycogen is a huge chain of glucoses and is the energy source your body uses first).
Usually the protein you eat is used by being broken down and the building blocks of the protein (the amino acids) are reused to build other proteins your body needs. Recommended levels of protein for this function is 46 grams a day for women and 56 for men, so you don't really need any more than this!
The body does not turn protein into glucose or fat. The chemistry is wrong and it just doesn't work that way. Ever. What CAN happen is that the body can burn protein for calories, and then the dietary fat and carbs are spared. THOSE can be stored as fat or turned into glucose for short-term energy.
Medical researcher for 25 years. Trying to find help for the obesity epidemic.
Fitness Minutes: (1,139)
1/31/09 8:20 A
it all depends on certain factors like weight, age, diet, activity level, and others. When I was actually in good shape I was consuming 1-1.5 grams of protein per pound of body weight. But, this was when I was hitting the weights hard.
I recommend 1 gram of protein per lb of lean body mass for both males and females who exercise at least 3 times per week. This is also with a low carb. intake.
Everything in balance as your body turns everything into glucose. In a 1600-1900 cal. diet, one must consume 2-4 protein servings which is 4 oz. In the 1900cal you can have 4-6 servings. I make sure that I eat protein with every meal
Fitness Minutes: (33,026)
1,805 1/31/09 12:24 A
Protein doesn't turn to fat, it's the extra calories that do. As far as health is concerned it depends on where you are getting your protein from, if you're only eating red meat and drinking whole milk, it may cause problems down the road with your cholesterol levels. I consume a lot of protein, and I've found over time that if I don't (not only are my macros out of whack) I get a lot hungrier a lot faster.
edit// lol, I didn't even notice your spelling error when I read that.
Edited by: THIRTEENREASONS at: 1/31/2009 (00:25)
- Occupational Therapist - Not as devoted to Sparking as I used to be - Powerlifting novice since 2009
Hell All, My question is how many grams of protein is considered to be too much and will likely turn into glucose? I'm consuming max 120 grams daily and I'm concerned if I'm taking in too much. I heard if you consume too much it turns into fat. Now what is considered too much?
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