WebMD/ February 21, 2012, 10:09 AM

Fructose off the hook for overweight and obesity?

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When it comes to weight gain, fructose should not be singled out for blame, a new review of the scientific literature suggests.

The review, in the Annals of Internal Medicine, shows that excessive calories -- and not any unique properties of fructose -- are more likely to lead to extra pounds.

"Is fructose really the source of all metabolic evil?" says researcher John Sievenpiper, MD, PhD, of McMaster University in Hamilton, Ontario, Canada. "From our standpoint, it does not look like it is."

However, the authors acknowledge that many of the studies they reviewed had serious shortcomings. Therefore, their conclusions are, in a word, inconclusive.

"Overall, the evidence from our analysis is too preliminary to guide food choices in the context of real-world intake patterns," they write.

41 Studies Analyzed

The review drew upon a large number of studies, each of which falls into one of two types.

Thirty-one of the studies divided the participants into two groups. Each group consumed the same amount of calories, but one group ate fructose while those in the other group ate a different type of carbohydrate. Doing so allowed the researchers to isolate fructose in order to determine its effect on body weight change. They found none.

The remaining 10 studies under review were based around adding calories. In each, half of the participants ate their usual diet, while the other half added fructose, a naturally occurring sweetener, to what they normally ate. The fructose groups did gain weight, but no more than would be expected from the amount of additional calories -- or energy -- that they took in as part of the studies.

"Energy seems to be the dominant factor," Sievenpiper says. "There was no effect from fructose."

Number of Calories Is Key

The review is likely to be controversial because increased fructose consumption has been targeted as a leading cause of the obesity epidemic, particularly in the form of high fructose corn syrup, a sweetener added to non-diet soft drinks and many other food products. Sievenpiper, however, says the debate over fructose misses the point.

"We feel the controversy has directed the issue away from over-consumption. Our data suggests that fructose plays the same role as any energy-dense substance."

Cleveland Clinic's Laura Jeffers, MEd, RD, LD, agrees.

"Fructose may not be the villain," says Jeffers, who reviewed the study for WebMD. "People should be aware of the total calories they're consuming rather than worrying about one type of sugar."

But do we need another study telling us that? No, says David Heber, MD, PhD, director of the UCLA Center for Human Nutrition.

"It's much ado about nothing," says Heber, who says that we should be focusing on how much fructose we consume and where we get it.

"There's too much fructose in our diets, and it's not coming from fruits and vegetables," says Heber, who was not involved in the study. "If fructose comes from those things, I have no problem with it."

Better Evidence Needed

Sievenpiper says his team's study was based on the "highest level of evidence available," but adds that "most of the trials had methodology issues, were too short, [and] were of poor quality. We don't think that this group of studies is particularly representative of real-world situations."

He would like to see large, long-term trials that may be better able to determine whether fructose itself -- rather than simply the amount of calories -- plays a particular role in weight gain.

"The studies need to be done in real-world formats," he says.

That means looking at the high fructose corn syrup that's added to so many products, at the fructose found in fruits and vegetables, and at the means by which fructose is consumed, such as in sweetened soft drinks.

"Energy in fluid form does not tend to be compensated," he says, meaning that it adds calories to the diet but does not satisfy hunger as well, which can easily lead to overindulgence. "Maybe the format is important."

Sievenpiper and his team received funding from several outside sources, including the Coca-Cola Company and the Calorie Control Council, a trade group that represents the diet food and beverage industry. However, he says that none of the funders had access to his data or influenced the review in any way.

© 2012 WebMD, LLC.. All Rights Reserved.
16 Comments Add a Comment
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chriswestland says:
Completely irresponsible journalism that gives publicity to science deniers on agricultural subsidies (in this case, the corn industry which couldn't survive without government subsidies). Glucose or what we generally call sugar or dextrose (NOT fructose which has to be processed by the liver into glucose) is the culprit behind the epidemic of obesity and diabetes and is ~45% of corn sweeteners, and most of cane sugar. This article takes the usual anti-science tack of admitting to many 'flawed studies' and much that we don't understand, to support the idea that 'calories' make us fat, but sugar doesn't ... and thus those agricultural subsidies should continue unabated.

CBS and WebMD ... you should both be ashamed of yourselves for propagating junk science ... indeed, you should both be ashamed of yourselves for promoting government subsidies for a public health threat more significant than tobacco or drugs. This is just irresponsible journalism.
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CaityCatherine replies:
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EXACTLY what I thought when I read this. This basically comes off as an advert for HFCS. When you have a headline that claims research indicates that it is not the cause of obesity, then in the second paragraph the researcher admits that the evidence is "inconclusive", well, then the headline is an outright and manipulative LIE and horrible journalism. I am really disappointed in CBS. I thought they were more responsible than this.

I recommend the lecture by Robert H. Lustig, MD, UCSF Professor of Pediatrics in the Division of Endocrinology who has absolutely no motivation to lie about his findings. He is a Peds doc who cares about his PATIENTS and is being honest about what is going on with children and obesity rates. His lecture is called, "Sugar: The Bitter Truth". He actually has real stats and research findings and science that he clearly explains in his lecture (a lecture given to other scientists and medical professionals--his peers--not a corporation, btw...). It is much more credible than this "inconclusive" crap here.
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Jaylah54 says:
Yes, we all know it's calories in versus calories out. But that's not the problem.

HFCS is addictive. Just like regular sugar, if you eat a lot of it, you tend to start not liking foods that aren't sweet.

Then add the fact that HFCS is in some pretty amazing stuff. Why would spaghetti sauce be made with sweetener? Ask any good Italian mother if she puts sugar in her marinara sauce and I'm sure she'd look at you like you sprouted a second head. For the record, Lidia Bastianich's Marinara Sauce recipe contains the following: 1/4 cup extra-virgin olive oil, 8 garlic cloves (peeled), 1 35-ounce can peeled Italian plum tomatoes (seeded and lightly crushed) with their liquid, kosher salt, peperoncino, 10 fresh basil leaves (torn into small pieces), freshly ground black pepper.

See any sugar in there?

It's in bread. In some brands of cottage cheese. In yogurt. In pickles. In some forms of lunch meat. In canned soups. In fact, if you look at the actual ingredients list of virtually all processed foods, it's in there.

Try going grocery shopping for one week, without buying anything with HFCS in it. (It can be done, but you're going to spend a lot more time in the kitchen cooking things from scratch.) Then watch to see your family's response to what they're eating. Kids (and even some adults) won't like it because it's not sweet. They won't be able to tell you that they don't like it because it's not sweet. They just know that it "doesn't taste right."
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mb99 says:
The headline is beyond annoying - what idiot wrote it? Just because fructose has no unique properties over excessive calories to cause obesity doesn't take it "off the hook" regarding obesity in this country.... IT'S BEING ADDED TO EVERYTHING... thus putting far more calories in people's diets than would otherwise be there. PEOPLE WHO WRITE HEADLINES SHOULD REFRAIN FROM TRYING TO DRAW CONCLUSIONS!
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Saturn66 says:
It's more complex than some of you are saying. Maybe the "simple" diet worked for you, but I live in a canyon where I walk every other day, I lift weights, and do floor exercises. I watch very little TV, mostly news--admittedly my job keeps me pretty sedentary, as is true for many of us. My calorie count is surprisingly low. But my weight kept climbing until I eliminated the HFCS. Try it for a month. If you already exercise and know that you don't overeat, this may work. I'd like to see HFCS outlawed much like what the government did during the "sugar wars" of years past. I think the outcome could be very interesting. Would we see our national obesity rates go down? Food for thought.
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Saturn66 says:
I don't believe it for a second. I eliminated high fructose corn syrup and lost weight. It wasn't easy, as it's even in Ketchup and relish, and sometimes it hides behind other names. You do have to wonder who paid for the so-called studies. There is something about HFCS that causes the body to hang onto calories--or some other mechanism that we don't understand. In this country everything is about money, so I'm guessing this has more to do with what the agricultural lobby wants than it does about facts. Most of us know the difference between carrots and cupcakes; it's not just about the calories. I strongly suspect we gain weight partly because of the altered chemicals in our bodies like HFCS.
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jasoncsaki says:
Off the hook? Only one problem... we can't believe anything these people say because corporations are behind the science. We live in the dark ages of big pharma and will not make significant progress in health science until we erase the profit motive from that field.
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Evirustheslaye replies:
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just because someone stands to make money from committing a certain action, doesn't mean they ARE committing that action. lets look at the data, not the emotion.
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ubiquitousnewt says:
I'm not buying it. We've had how many studies linking high fructose corn syrup to weird metabolic effects, and one *review* comes out and claims that, without new research, they have sufficient info to dismiss all that? ...Man, I hate reviews.
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inverse137 replies:
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But this is exactly why science works. This "study" is subject to peer review. If it doesn't stand up to peer review it is a flawed study.

The unfortunate side is that the general media won't really report on the peer review articles that will follow.
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thomasmc1957 says:
Why do they never mention who paid for these "studies"?!?

My guess would be the corn lobby.
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Evirustheslaye replies:
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why do conspiracy theorists automatically assume that the absence of evidence is proof of the conspiracy?
DaSizzle replies:
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Exactly Thomas, I wouldn't believe science either. Want your tin foil hat back?
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liveloveforgod says:
Weight loss is simple. If you have a stubborn insulin you hold fat and have a hard time losing weight. You can eat very little and the weight still does not come off. YOU HAVE STUBBORN INSULIN that holds fat and diets won't work

BUT when researchers used a specialized diabetes diet on people with OR without diabetes they lost the stubborn insulin and the weight

just google SPIRIT HAPPY DIET
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inverse137 replies:
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Your premise is true for a small minority. The overwhelming majority of Americans eat too many calories of "bad food" and do not excercise enough.

I could also make a statement that "weight loss is simple, you just need to get your hypo-thyroid condition treated." Which is true for a small percentage of the population with thyroid conditions.

Don't eat processed foods, don't drink sugary drinks, eat LOTS of fruits and vegatables, don't eat any read meat, eat fish and chicken and don't cook with lards, fats and oils (except olive oil,) eat only WHOLE GRAINS (no enriched four, AND excercise.

There, you now have the secret of losing weight and it won't cost you thousands of dollars.

The other FREE secret is take your TV outside, put it in your driveway, get in your car, put it in reverse and back over your TV. That too will guarantee weight loss within 12 months.
Evirustheslaye replies:
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can you use a more scientific term for a molecule than "stubborn"
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