How much glucose in a gram of carbohydrate?

Here’s a puzzle that’s bothered me lately:

A gram of glucose should raise your blood glucose by 17 mg/dl:

1,000 mg / 56 deciliters = 17.8 mg/dl

Yet eating a gram of carbohydrate only raises BG by 4 mg/dl

4 mg/dl * 56 deciliters = 0.224 grams one gram of carbohydrate == 0.224 grams of glucose?

Evidently the body consumes at least 150 grams of glucose/day:

about 100 g of glucose/d are irreversibly oxidized by the brain from the age of 3–4 y onward. However, this excludes recycled carbon, gluconeogenic carbon, for example from glycerol, and it does not account for glucose used by other non-CNS tissues. For example, in the adult, muscle and other non-CNS account for an additional 20–30 g of glucose daily. For this reason a safety margin of 50 g/d is arbitrarily added to the value of 100 g/d, in order to supply the 150 grams of glucose, I need to consume at least 600 grams of carbohydrate per day?

At a maximum rate of 60 grams of carbohydrate/hour, looks like I'd better get busy...

Not all carbohydrates are glucose though, there’s lactose, fructose, Budweiser, etc.? I think they all have sort of different “curves” that play out. This is a totally unscientific hunch but well, you know?

Huh?I’m not a scientist and have no idea what any of that means, but see a couple problems in it from a D point of view. First of all, we are all different in how much carbs raise our blood sugar. There is no formula that holds true for all of us. Second of all, I hope you are kidding, but if not, please reconsider whatever convoluted science is convincing you that you should eat 600 grams of carbs per day!

4193-hgmsraiseetc.pdf (679 KB)

If you’re “How FUNNY!” comment relates to my statement that you can’t determine exactly how much of a rise in blood sugar each person gets from a formula, you could probably find a less rude way to disagree with me. I have no idea what the source of your table is, but I stand by my opinion based on my own experience and that of many others on here. Some people seem much more “carb sensitive” and have large rise in BG with a relatively minor intake of carbs. Other people can eat large amounts of carbs without a significant spike. It also seems to vary by type of carb. For example, for many of us (but not all, of course), rice will raise our blood sugar an inexplicably large amount and this despite what would be a reasonable bolus for the same number of “other” carbs. All carbs are definitely not equal

Like everything with Diabetes, formulas and rules are good for guidelines but have almost as many exceptions to the rule as there are Diabetics!

On the average 1 gram of carbohydrate usually raises the blood sugar 3-5 mg/dl. It varies by body weight, or probably more correctly, by the total amount of blood. I’ve never heard of anyone claiming a 17 mg/dl rise from eating 1 gram of CHO.

I’m guessing that 25% of the carbs you eat are broken down into glucose (what happens to the other 75%?)… so how else do you get 150 grams of glucose?

Something doesn’t add up here… and that’s what’s got me puzzled.

It would be indented if it was a reply to your post. It looks to me like the How Funny comment was in regards to the notion that diabetics are supposed to consume 600 carbs a day. Which is kind of funny. I’m pretty sure the OP was being sarcastic that we need to eat that many carbs as well.

Perhaps you are right, and I am being too sensitive Jeska! I just made that assumption because a table of carb rise was included.

A table that I don’t fit lol

And I hope I’m right that it wasn’t directed toward you :o)

Fats and proteins also get converted to glucose in the body, granted in a smaller percentage than carbohydrates. So it’s not just all about carbohydrates…

Well, crap, Bud is a carb?

Bud Select 55 is only 1.9G, “the lightest beer in the world” cheers

1 gram of carb raises me over 10mg/dl…& I’m not a tiny person…5’6" & 150-155lbs (68.31kg - 70.31kg)…am I really that weird? =[

The amount of blood in your body is roughly proportional to the size of your body. The average person has 5 liters of blood. Thus 1g of pure glucose that is all absorbed would raise your blood sugar on average 1g/5l = 20 mg/dl. However, for a variety of reasons the conversion rates are not perfect and there are some significant ineffciencies. And as noted, not all carbs convert fully to blood sugar, table sugar is half glucose/half fructose, and would have only half an effect on blood sugar. Bernstein suggests that a gram of glucose ingested raises you 5-10 mg/dl. Personally, I am a big guy, a gram raises me 2-3 mg/dl.

Research seems to indicate that most of the body function can actually run on ketones. Most believe that only the brain and red blood cells require glucose and in fact recent work seems to suggest that the brain can also operate quite well on ketones. Still your brain and red blood cells perhaps require about 25-50 g of glucose/day all of which can be synthesized from proteins. Thus the minimum level of dietary carbohydrate required to sustain life is zero.

OK, now you’ve got me worried (what me?)… is there really any point to counting carbs then? If one gram of carb raises BG 20 mg/dl if pure glucose… but 0 mg/dl if pure fructose, then you might as well just roll the dice. “Nutrition Facts” labels list “Sugars”, but don’t go into details about the structure of the sugar…

If you ingest a gram of glucose, why is it 5-10 mg/dl [Bernstein] or 2-3 mg/dl [bsc], and not 20mg/dl? What’s being converted?

You can get the brain glucose from protein conversion… but that’s less efficient. About 58% conversion of “excess protein”, whatever that is. Carbohydrate conversion is supposed to 100%, so all these numbers seem kind of random.

Seems like I make these life-and-death decisions everyday with my injections, without really knowing what’s going on…

Fructose has a marked effect on BG. Eat anything with fructose to see the result. If fructose didn’t, we’d all be using that instead of artificial sweeteners.

The difference of the effects of 1 gram of glucose is due to an individual’s size/weight. I’m small. One gram of glucose raises me consistently 10 pts. I know this from correcting lows. Dextrose works more quickly, but I hate the taste of dextrose tablets.

From eating low carb for almost three years, my body has become quite efficient at converting protein to glucose. I imagine I’m not unique in this regard. I bolus for carbs & also bolus for protein. It seems to be a little known fact among healthcare professionals that protein converts to glucose, but diabetics know from experience that high protein meals effect BG.

Various biochemical processes also contribute glucose to blood, such as cells dying.

I don’t see these numbers as random. Complex, yes, but not random. Based on individual biochemistry, effects differ. The only way I’ve found is to record food & their results to understand what’s going on. There is no perfect formula, just trial & error & limiting the variables that we can.

This link has good info on Carbohydrate metabolism

The liver will convert most fructose to glucose. Fructose and glucose in excess leads the liver to convert the fructose to triglyceride. If you take the proper insulin dose there is no excess fructose in the blood to convert to triglyceride as the liver will continue to convert the fructose to glucose since that is the only thing the cell can use to provide energy. This is the reason blood sugar control and not over consuming fructose and glucose is so important if you have a higher propensity towards elevated triglycerides. If you do not take the proper insulin dose then it dosen’t matter. Your blood glucose will be elevated anyway!

And yes the liver is effecient enough at converting amino acids into glucose that carbohydrate ingestion is not mandatory and most will have no issue getting all the glucose they need without it.

Personally I am not a big ADA fan but I don’t believe I ever heard the ADA claim that carbohydrate consumption was required to sustain life. They keep talking about 130 grams needed for “optimal brain function” whatever that means?

Well, I guess it means that the ADA has not been eating 130 grams a day cause their brain function is far from optimal.

ps. The 130 gm per day is a recommendation from the IOM, which if you read carefully, they derived based on the amount that was thought to be required to support brain function, but recent research suggests the brain works just fine on ketones. The IOM also noted that “The amount of dietary carbohydrate that confers optimal health in humans is unknown (IOM, 2006).

Can you lead me to the 130 gram recommendation citation please? I just started looking for it but hoped someone could tell me where this research can be found.