Tuesday, January 19, 2010

Glucomannan: the Super Weight Loss Satiety Support Supplement (with Fiber, too)

ResearchBlogging.org Lawd, it can be hard when dieting to get enough fiber. Turns out there's a supplement that's been investigated since the 198o's at least that actually seems to keep showing up only positive results in all sorts of contexts. Glucomannan. The fiber of the Konjac root. A soluble fiber, but, what's more, it seems to enhance satiety with less food. And is safe. And seems to do many other Wonderful Things.

I first heard about this stuff in a Precision Nutrition interview with phd Casandra Forsythe of New Rules of Lifting for Women fame. Then there's this cool video on T-Nation showing how much liquid a bit of glucomannan absorbs.

Success -on so many levels.
Studies looking at adding glucomannan to calorie-restricted diets have consistently found that glucomannan groups lose more fat than the non-fiber'd up groups. In one study in 2005, over 5 weeks, the GM group dropped an additional .8/kg. Indeed, in a review of research done on GM and obesity up to 2005 found that adding 2-4g of the stuff to food a day had good weightloss effects while also doing other good things like lipid status, carb tolerance and satiety (as talked about way back in 92 as well).

Fat Related.
The review reiterated what's been one of the earliest findings with GM: resduced serum cholesterol AND ldl (1984). IN looking at likely the most popular soluble fiber sup, psyllium, it *seems* that the results on lipoproteins levels are better with GM too.

Weight Loss. In the weightloss space, though, terms like carb tolerance and statiety are really important. Does the person on the calorie restricted diet feel full? That may reduce cheating. Satiety turns out to be a huge topic, and achieving satiety on 1200kcals, for example, is no small thing.

Likewise, being better able to handle starchy carbs means better insulin sensitivity means potentially not taking on board quite so many since one's getting the benefit from them that's approriate with appropriate insulin response.

Related Symptoms? Heck probiotics (eat yogurt) + GM have been shown to reduce acne.

Better Movement. Likekwise having good bowel movements while dieting can be a real challenge. Since gut health is a huge indicator it seems of overall wellbeing, lots of dieters tend to reach for psyllium as a main fiber solutions.

Turns out, though, there are advantages to going the soluble route with glucomannan. Besides just getting better more regular BM's, in a 2006 study, the group using GM (aka Konjac) also shows a significant increase in bifidobacteria, lactobacilli and total bacteria. You know, that friendly stuff we need. The GM "supplement also promoted colonic fermentation as shown in the decreased fecal pH (P < href="http://www.ncbi.nlm.nih.gov/pubmed/19282532">this is one supplement that's actually being suggested can play a role as part of a regimen with kids, where other diet approaches - like drugs - cannot.

Why Does it Work for Weight Loss?
Glucomannan does so many good things, it sounds like it's compressing every thing that goes along with just eating right into one humble but potent powder. But for most folks doing diets, a biggie reason for adding a little GM (like 4 g, 1.5/meal mixed in with food, not caps) to our lives may be that simply eating less leaves us feeling fuller rather than lesser.

This effect of feeling full is not necessarily obvious - having a full gut does not always leave one feeling satisfied (review of gut triggering brain mechanisms; review of meal size brain signaling). One can have their stomach filled up with water, and as many dieters know, a stomach that's full - of water - doesn't necessarily result in a lack of desire to eat more. So what glucomannan seems to be doing within food use is to assist in having less food register as more satisfying, tripping off those sensors in the gut/brain signaling that say less is more in this case. That is very cool.

That it also helps with "increased fecal energy" as that 2005 review suggests, may be one more reason towards simply feeling better with what one is doing more of the day - i speculate. But feeling good is feeeling good.

Recommendation: If you are struggling with aspects of low-cal'ing, from feeling full, to having healthy bowel movements, glucomannan may be just the ticket. If you have LDL issues as well and are dieting, this may also be a good supplement in any case. Check with your Doc if you're on any medication that may be counterindicated.


Birketvedt GS, Shimshi M, Erling T, & Florholmen J (2005). Experiences with three different fiber supplements in weight reduction. Medical science monitor : international medical journal of experimental and clinical research, 11 (1) PMID: 15614200

Keithley J, & Swanson B (2005). Glucomannan and obesity: a critical review. Alternative therapies in health and medicine, 11 (6), 30-4 PMID: 16320857

Walsh DE, Yaghoubian V, & Behforooz A (1984). Effect of glucomannan on obese patients: a clinical study. International journal of obesity, 8 (4), 289-93 PMID: 6096282

Sartore, G., Reitano, R., Barison, A., Magnanini, P., Cosma, C., Burlina, S., Manzato, E., Fedele, D., & Lapolla, A. (2009). The effects of psyllium on lipoproteins in type II diabetic patients European Journal of Clinical Nutrition, 63 (10), 1269-1271 DOI: 10.1038/ejcn.2009.60

Al-Ghazzewi FH, & Tester RF (2009). Effect of konjac glucomannan hydrolysates and probiotics on the growth of the skin bacterium Propionibacterium acnes in vitro. International journal of cosmetic science PMID: 19818083

Marsicano LJ, Berrizbeitia ML, & Mondelo A (1995). [Use of glucomannan dietary fiber in changes in intestinal habit] G.E.N, 49 (1), 7-14 PMID: 8566676

deFonseka A, & Kaunitz J (2009). Gut sensing mechanisms. Current gastroenterology reports, 11 (6), 442-7 PMID: 19903419

Grill, H. (2010). Leptin and the systems neuroscience of meal size control Frontiers in Neuroendocrinology, 31 (1), 61-78 DOI: 10.1016/j.yfrne.2009.10.005


Roland Fisher said...

I've had better results with me and mine since putting a focus on being present to the body before, during and after eating. Getting to know when I'm truly hungry, and on the flip side, truly satiated.

This can only help, thanks mc!

L. Wu said...

Why not just eat more fiber? Real Food =)

Hemp bagels from French Meadow Bakery (frozen section of Whole Foods, for example) give you 50% of the fiber you need in one day... or there's always domesticated/really-wild wild rice etc.

dr. m.c. said...

Thanks ROland. let me know if you give this a go, how it goes.

sure hemp bagels and wild rice can be dandy. but remember the context in this particular case:

when people are on low cal/low carb diets, something like a hemp bagel, or wild rice is not on the menu. That said, konjac is pretty much just squished root, so not unwhole either, really?

thanks for dropping by.



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