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Protein converting to glucose

I found a website or maybe it was a magazine article that described that on a Low-carb/High-protein diet the body will start to convert protein to glucose.

This process burns additional calories and raises your metabolism. Does anyone know anything about this? I can’t find the information anywhere. I think it was called protein glycogenisis.

It’s called gluconeogenesis (the creation of new glucose). The nitrogen containing portion of protein is removed in a process called deamination (amino removal) so the body can use then use what is left over as energy. This occurs when muscle protein is used for energy purposes and is generally thought of (by bodybuilders) as a bad thing.

Thanks Joel,

Yet this site claimed that the body can convert protein from diet in the same way. Is this hogwash?

I’m sure it’s possible, but so unlikely that it probably wont happen if protein intake is adequate.

I disagree here. Protein use as a fuel does happen in dieters. Why dont you try getting ample calories, yet not eating fat or carbs and see what happens. You tend to burn the most abundant fuel source and in this case it’s protein. Since, it is an incredibly inefficient source of energy, muscle loss is often the result.

58% of dietary protein converts to glucose, and if my memory serves correctly (which it might not), only 25% of protein intake will leave the liver and of this 25%, 75% is the branch chain amino acids. So if you eat enough protein to keep your system running on glucose (instead of ketons for example) and your major source of fuel is protein, you will often lose muscle.

Protein well above and beyond your requirements can make you ‘protein starved’. Protein is not protein sparing – sugar and ketones are protein sparing.

I agree with thunder on this one we just learned this today in out nutrition class…take in at least 60 -110 carbs to spare protein from being broken down, otherwise like on low carb diets you’ll lose muscle, carbs are very protein sparing thats why very very low carb diets are good for muscle gain or maintainence, but something like the t-dawg…this is where that diet really shines…


thats was supp to be an aren’t* good


I should have said protein and calorie intake.

Having ample calories when you eat 100% protein will have the same end result – a disaster.

Pugsly, did they also teach you that carbs are fat sparing?

I remember reading in Bodyopus that many people never acheive ketosis on diets like the Atkins, because the of the level of protein intake. Some of the protein converts to glucose, which can prevent your blood sugar from dropping low enough for ketosis to start. (Which is why the Ducahine recommended a diet of 75% fat and 25% protein to plumet you into ketosis in a matter of only two days.)

Following up on Jeff’s post, that’s also why Lyle McDonald recommends that one get slightly less than 1 g./protein/lb/day while on a CKD – to prevent gluconeogenesis from kicking you out of ketosis. The 58% conversion rate that Thunder cited is a maximum – under ordinary dietary conditions (i.e., while ingesting adequate carbs), I belive it’s far less than that.

Of course carbs are fat sparing they are our primary source of energy. What i am saying is that when you are low carb dieting, most any human needs at least 50-100 grams of carbs a day to spar5e protein and muscle for that matter. So really think about it I don’t think that 50 -100 carbs a day is gonna spare that much fat from you losing it. Taking in 50-100 grams of carbs a day isn’t going to stop your fat loss very little if at all in the scheme of things but not taking in at least this amount with cause ketosis which will then cause protein being broken down for energy in the form of glucose from either muscle or dietary protein sources.


Let’s take a little poll. Who on this board consumes maintenance calories with a macro breakdown of 100/0/0?

Honestly, I have no idea what this even has to do w/ what I previously said anyway.

Joel, that was clearly used as an example to reiterate that you’ll still lose muscle even with ample calories, if there isn’t enough fat or carbs in your diet.

Pugsley, actually ketosis is protein sparing. Ketosis is metabolically simliar to starvation, and once your body adapts, it’s a very protein sparing state. Think about starvation – it’s not like there is an exponential decrease in muscle. I had data on this from one of my old classes, but can’t find it right now.

You’ll only oxidize protein for fuel when your system is running on sugar. When you make the metabolic switch to ketones as a primary fuel source, the need to convert protein to sugar isn’t needed as much. The end result is less protein oxidized in that state – muscle sparing.

As well, technically speaking, anything under about 100 g of carbs will have you showing ketones. No, probably not in your urine, but on a blood test, yes you’d show them.

Gluconeogenesis will happen for the most part everyday (especially after the overnight fast).
It doesnt matter if carbs are fat sparing or protein sparing. ITs the overall daily energy, protein and fat balance that will make a difference.
During a diet you will lose some lean mass no matter what you will do, the differneces between different diets (keto, low carb high carb) dont make much of a difference to it overall (as long as adequate protein is supplied)

Saying “as long as adequate protein is supplied” is grossly simplistic. It’s definitely not that cut and dry.

I’d like to refer back to something Pugs said about where the t-dawg diet shines. It’s also where I thing massice eating is so brilliant. If you take in carbs where they are most needed - 6 hours post workout (P+C), then low carbs outside of that window (P+F), you end up controlling the situation.

1)You use the carbs (rather than have them stored as fat, and spare your existing fat)

2)and you burn fat for energy outside of that post-w/o window so it’s muscle sparing b/c of the reduced insulin response and enhanced fat burning.

I think it’s all about eating the approapriate amount of carbs so muscle and time it properly so muscle is gained, but fat is still being burned b/c b/c carbs are not being over-consumed.

Perhaps this is an oversimplification, but it makes all the sense in the world to me.

I think everyone knew what I meant.

Question 2 Mayfield: Do you or anyone else think that ustilizing this style [(P+C) then (P+F)] actually causes the body to switch from burning carbs when P+C are present to then buring store fat (ketosis) when P+F are present?

I wonder because I think some might argue that it would take a little bit longer for the body to register the change - maybe not though. Myself, I have no book knowledge on this but the thought crossed my mind.

Cranium - That’s a good point, and I don’t think it happens ‘overnight’ for inactive people on a high carb diet. However, for active people who consume and appropriate amount of carbs (dep on size and activity) the body body becomes very adept at burning the proper fuel stores, whether it be fat or carbs.

Basically what happens is excess carbs are stored as fat, so as long too much carb is being consumed, the body is going to try to burn them off before fat, and the excess stored as fat. To make it worse, the extra insulin from carbs prevents glucagon (which mobilizes fat stores for use) formation and release. So if you consume too much carb and are inactive, the body can ‘forget’ how to burn fat.

Once a person sets things in motion by being acive and consuming the right amount of carbs, the body becomes very good at burning fat b/c the carbs that are comsumed are mostly taken up in glycogen synthesis and stored in muscle tissue due to the activity level. If carbs aren’t over consumed, there won’t be an excess to be stored as fat and initiate the cycle I described above.