# Too Much Sugar Is Bad, But Which Sugar Is Worse: Fructose Or Glucose?



## Arnold (Apr 25, 2009)

*Too Much Sugar Is Bad, But Which Sugar Is Worse: Fructose Or Glucose?*

ScienceDaily (Apr. 25, 2009) ??? In 2005, the average American consumed 64kg of added sugar, a sizeable proportion of which came through drinking soft drinks. Now, in a 10-week study, Peter Havel and colleagues, at the University of California at Davis, Davis, have provided evidence that human consumption of fructose-sweetened but not glucose-sweetened beverages can adversely affect both sensitivity to the hormone insulin and how the body handles fats, creating medical conditions that increase susceptibility to heart attack and stroke.

In the study, overweight and obese individuals consumed glucose- or fructose-sweetened beverages that provided 25% of their energy requirements for 10 weeks. During this period, individuals in both groups put on about the same amount of weight, but only those consuming fructose-sweetened beverages exhibited an increase in intraabdominal fat.

Further, only these individuals became less sensitive to the hormone insulin (which controls glucose levels in the blood) and showed signs of dyslipidemia (increased levels of fat-soluble molecules known as lipids in the blood).

As discussed in an accompanying commentary by Susanna Hofmann and Matthias Tschöp, although these are signs of the metabolic syndrome, which increases an individual's risk of heart attack, the long-term affects of fructose over-consumption on susceptibility to heart attack remain unknown.

Journal reference:
   1. Stanhope et al. Consuming fructose-sweetened, not glucose-sweetened, beverages increases visceral adiposity and lipids and decreases insulin sensitivity in overweight/obese humans. Journal of Clinical Investigation, 2009; DOI: 10.1172/JCI37385

Adapted from materials provided by Journal of Clinical Investigation, via EurekAlert!, a service of AAAS.

article source


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## danzik17 (Apr 25, 2009)

Interesting.  Yet another reason to limit the intake of fruit as a source of carbs.


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## Built (Apr 25, 2009)

Fruit generally isn't all that high in fructose - roughly half the sugar in fruit comes directly or indirectly from fructose (as sucrose, for example, which is broken down into a glucose and a fructose). 

For example, a medium apple has, according to fitday (which in turn gets data from the USDA) has 19.1g of carbohydrate, 3.3g of which come from soluble and insoluble fibre. Of the remaining 15.8g of carbohydrate, about half - just under 8g - comes from free or bound fructose. 

Contrast this with a 6.75 ounce juice box, which contains 24.4g of carbohydrate and virtually no fibre (0.2g). 

So a little kid knocking back a juice box is consuming about 12g of fructose and almost a hundred calories. Something tells me that kid would feel a lot more full after eating the apple, but we're told this is equivalent to a serving of fruit, right? Well, it's not. It's just liquid candy. It has the same sugar profile as a HFCS-sweetened soda pop, and the same calories, too. And they're very easy calories to consume - I've seen little kids who drink fruit juice all day. I haven't seen too many little kids eating half a dozen apples at a sitting!

The moral of the story: eat fruit; don't drink it.


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## danzik17 (Apr 25, 2009)

I'm not saying eliminate it, just to limit it to 1-2 pieces per day maybe.

There was a point a few years ago where I WAS eating 6-7 apples per day as part of my diet because I didn't know any of that info


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## Built (Apr 25, 2009)

Gotcha. Eat lower-sugar fruits such as berries. They're higher in fibre and antioxidants, and very flavorful as an added perk.


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## danzik17 (Apr 25, 2009)

Don't have to tell me that, strawberries are in season right now are are freaking *delicious*.  I've been routinely having 2lbs of them on Fridays as part of my refeeds


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## emitecaps (Apr 25, 2009)

danzik17 said:


> I'm not saying eliminate it, just to limit it to 1-2 pieces per day maybe.
> 
> There was a point a few years ago where I WAS eating 6-7 apples per day as part of my diet because I didn't know any of that info



Is it really that bad though if you are eating those apples spread throughout the day? I doubt 10 or even 20g of carbs will screw up insulin levels or induce insulin resistance. Now, if you were consuming 4 apples in a sitting then there may be cause for concern.


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## Built (Apr 25, 2009)

It's not about the carbs, emitecaps, it's the fructose in particular. This isn't about insulin.


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## Bennuendo (Apr 25, 2009)

Built said:


> Fruit generally isn't all that high in fructose - roughly half the sugar in fruit comes directly or indirectly from fructose (as sucrose, for example, which is broken down into a glucose and a fructose).
> 
> For example, a medium apple has, according to fitday (which in turn gets data from the USDA) has 19.1g of carbohydrate, 3.3g of which come from soluble and insoluble fibre. Of the remaining 15.8g of carbohydrate, about half - just under 8g - comes from free or bound fructose.
> 
> ...




Yeah I'm going to guess these drinks were sweetened with high fructose corn syrup.. not really the same as fruit.. since you have the fiber and what not and not such a big hit of fructose.


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## Built (Apr 25, 2009)

The juice I looked up was unsweetened. 

The sugar profile for fruit juice and for soda is virtually identical. HFCS55 - which has 55% fructose, 45% glucose is essentially the same thing as sucrose once sucrase hydrolyzes it into glucose and fructose.


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## Bennuendo (Apr 26, 2009)

Built said:


> The juice I looked up was unsweetened.
> 
> The sugar profile for fruit juice and for soda is virtually identical. HFCS55 - which has 55% fructose, 45% glucose is essentially the same thing as sucrose once sucrase hydrolyzes it into glucose and fructose.



Ahh ok.. I meant the ones in the study could possibly be HFCS drinks.. a lot of drinks are now a days, even gatorade.  But I do agree, you're going to get more out of eating a fruit than drinking the juice especially if there's no pulp.


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## Built (Apr 26, 2009)

My point is that HFCS in soda and fructose-sucrose-dextrose in fruit are the same sugars in virtually the same proportions. 

That's why it's best to think of juice the same way as you think of pop: liquid candy. 

Like I said - eat fruit, don't drink it. And for Heaven's sake, don't give juice to children!


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## Bennuendo (Apr 26, 2009)

Built said:


> My point is that HFCS in soda and fructose-sucrose-dextrose in fruit are the same sugars in virtually the same proportions.
> 
> That's why it's best to think of juice the same way as you think of pop: liquid candy.
> 
> Like I said - eat fruit, don't drink it. And for Heaven's sake, don't give juice to children!



Ah alright I see what you're saying.. and yeah I agree kids will down that juice like there's no tomorrow.. and a lot of parents will end up giving them juice that's only 10% real juice or just straight sugar water (koolaid).  

Thankfully I'm more of a water, skim milk, oolong tea drinker.. I love whole fruits.


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## someguy1984 (Apr 26, 2009)

Built said:


> The juice I looked up was unsweetened.
> 
> The sugar profile for fruit juice and for soda is virtually identical. HFCS55 - which has 55% fructose, 45% glucose is essentially the same thing as sucrose once sucrase hydrolyzes it into glucose and fructose.



I'm lost, what is the difference between fructose, glucose and sucrase?

Isn't fructose the stuff in soda? How does this all work...Seems confusing, maybe you can explain it easily.


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## Built (Apr 26, 2009)

Bennuendo said:


> Ah alright I see what you're saying.. and yeah I agree kids will down that juice like there's no tomorrow.. and a lot of parents will end up giving them juice that's only 10% real juice or just straight sugar water (koolaid).



It wouldn't matter. 100% pure fruit juice would do them just as much harm. 


someguy1984 said:


> I'm lost, what is the difference between fructose, glucose and sucrase?
> 
> Isn't fructose the stuff in soda? How does this all work...Seems confusing, maybe you can explain it easily.


Sucrose = table sugar = fructose bound to glucose. Sucrase enzyme in the body breaks them apart.

Glucose AKA dextrose AKA dextro rotatory glucose AKA blood sugar. Stimulates insulin response. 

HFCS55 = high fructose corn syrup =55% fructose, 45% glucose. Virtually identical to sucrose, except it doesn't need to be hydrolyzed by sucrase into fructose and glucose. 

That help?


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## someguy1984 (Apr 26, 2009)

Built said:


> It wouldn't matter. 100% pure fruit juice would do them just as much harm.
> 
> Sucrose = table sugar = fructose bound to glucose. Sucrase enzyme in the body breaks them apart.
> 
> ...



Yes, it does. 

So, would white rice be glucose?

What are some examples of foods that are glucose? I know fructose and sucrose would be found in soda, right? Apple juice, sugary beverages...


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## Built (Apr 26, 2009)

All starches are glucose polymers. 

Any fruit will have fructose and other sugars. 

Table sugar and soda pop either have sucrose, which breaks down in the body into fructose and glucose, or HFCS which already IS fructose and sucrose. 

Other disaccharides exist - lactose for example, which I *think* is a galactose and a glucose. Your body breaks these apart with lactase enzyme. If deficient, you have lactose intolerance.


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## jhawkin1 (Apr 26, 2009)

I'm glad I saw this thread...so for cutting diets- even if you are at a caloric deficit for the day, one should not consume too much sugar, even if it fits into their daily macros?

I love to snack on an italian ice at night before bed- and I am still well below maintenance (i get my 1g/lb of protein at least, and 1/2g/lb for fats)- will this be a problem *in terms of physique* (will it have an effect on my cutting, if my cals in is still well below cals out by the end of the day?


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## Built (Apr 26, 2009)

You'll be fine. Your body can handle a little fructose - some folks drink pop or fruit juice all day and that's probably not a very good idea for health, period. It's not a natural amount of fructose to take in by ANY stretch of the imagination.


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## emitecaps (Apr 27, 2009)

Built said:


> It's not about the carbs, emitecaps, it's the fructose in particular. This isn't about insulin.



I thought the whole issue was about insulin or insulin resistance triggered by fructose. If not then what's the issue with consuming fructose? An apple might contain a few grams of fructose so I don't think it will elicit any adverse insulin response. If you are eating several at a sitting then this would be different. Maybe I'm just confused here though.


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## Built (Apr 27, 2009)

emitecaps said:


> I thought the whole issue was about insulin or insulin resistance triggered by fructose. If not then what's the issue with consuming fructose? An apple might contain a few grams of fructose so I don't think it will elicit any adverse insulin response. If you are eating several at a sitting then this would be different. Maybe I'm just confused here though.



Hmmm… it's not that consuming fructose will cause insulin resistance - it's that OVER consumption of fructose (which is really, REALLY easy to do if you drink a lot of fruit juice or soda pop) loads up your liver beyond its capacity (the adult liver has at most about a 100g capacity for glycogen). When this happens, the liver cannot store any more and starts spitting out the excess in a storage form - triglyceride - and chronic elevation of triglycerides in the bloodstream may increase the risk for insulin resistance. 

From http://high-fat-nutrition.blogspot.com/2009/03/fructose-glucose-and-cholesterol.html:
"If glucose is being consumed within the ability of the liver to store it as glycogen there is no reason to convert it to fat and so there is no fat to export as triglycerides. Fructose immediately converts to fat and any fat produced in excess of the needs of the liver will be shipped out as LDL precursor particles, raising both LDL and TC."
Furthermore, because fructose doesn't require insulin in order to be metabolized, the postprandial satiety that insulin evokes in healthy-lean individuals is absent - so it's very, very easy to continue to over consume not just the fructose, but food in general. 

So you have a few problems that conspire to mess you up: a limited-capacity liver that loads up very quickly and then spills out excess as elevated blood lipids, and a disrupted satiety-signal following your meal. Combine these with an ad libitum (ie not calorie-controlled) diet and you have a recipe for obesity.


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## someguy1984 (Apr 27, 2009)

Built said:


> Hmmm… it's not that consuming fructose will cause insulin resistance - it's that OVER consumption of fructose (which is really, REALLY easy to do if you drink a lot of fruit juice or soda pop) loads up your liver beyond its capacity (the adult liver has at most about a 100g capacity for glycogen). When this happens, the liver cannot store any more and starts spitting out the excess in a storage form - triglyceride - and chronic elevation of triglycerides in the bloodstream may increase the risk for insulin resistance.
> 
> From http://high-fat-nutrition.blogspot.com/2009/03/fructose-glucose-and-cholesterol.html:
> "If glucose is being consumed within the ability of the liver to store it as glycogen there is no reason to convert it to fat and so there is no fat to export as triglycerides. Fructose immediately converts to fat and any fat produced in excess of the needs of the liver will be shipped out as LDL precursor particles, raising both LDL and TC."
> ...



So, how much fructose daily would be over consuming? How much should i not go over a day? 50g?


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## Built (Apr 27, 2009)

Honestly, I'm not sure. I think Lyle McD suggested not going over 50g for carbups, but for day to day... Honestly, you'd get 50g in 100g of ordinary table sugar - about half a cup. You eat that kind of table sugar daily? You drink a lot of pop or juice? If not, I wouldn't worry about it.


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## someguy1984 (Apr 27, 2009)

Built said:


> Honestly, I'm not sure. I think Lyle McD suggested not going over 50g for carbups, but for day to day... Honestly, you'd get 50g in 100g of ordinary table sugar - about half a cup. You eat that kind of table sugar daily? You drink a lot of pop or juice? If not, I wouldn't worry about it.



I don't use table sugar, or drink anything with sugar in it. The only thing bad i have is diet soda on occasion. (The caffeine picks me up a bit) 

I don't eat fruit to be honest with you. I don't know why, i just never do...Probably not a good thing, but never got into it. I'd say the only sugar i get is from protein bars, (never more than 4g of sugar and i count sugar alcohols) whey protein has 1g, natural peanut butter 1g, roasted peanuts has a couple, and that's really about it. I would say bread, but i don't eat it. Hmm, I'm sure their are plenty of hidden sugars i have elsewhere...Which is why i asked...


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## Built (Apr 27, 2009)

Bread will be mostly glucose polymers, the sugar is there to feed the yeast for the most part. 

I wouldn't worry about it. Not with your diet. 

I don't eat a lot of fruit either. Never really agreed with me to eat much of it.


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## someguy1984 (Apr 27, 2009)

Built said:


> Bread will be mostly glucose polymers, the sugar is there to feed the yeast for the most part.
> 
> I wouldn't worry about it. Not with your diet.
> 
> I don't eat a lot of fruit either. Never really agreed with me to eat much of it.



Alright, thanks. 

Also, did you read the "should i bulk or cut" thread? Take a look and tell me what you think. This guy made a post about another persons opinion on "bulking." He was implying you should never get over 10% body fat all year...

If this is true, what would a person do if they were 5'8, 150lbs, 14% body fat. It doesn't seem like it would make much sense to cut, since they would end up weighing like 138lbs...You should take a look at the thread....I'm confused. I see his point, but i think certain situations don't make sense with this 10% body fat theory...

He claims that if your over 10% body fat, to cut down and then start adding calories...


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## Built (Apr 27, 2009)

I don't think that's a fair assessment. There seems to be a sweet spot for bulking, for most men that's probably around 15% give or take. I'd just gradually increase calories and keep lifting - or bulk faster, but accept looking juicy for a bit.


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