Monday, May 11, 2015

Been Preloading W/ Guar Gum & FOS For One Week and Your Abs Still Don't Shine? Study Shows: It May Take Less Fiber, but More Time for the Anti-Obesity Effects to Show

Luckily, you don't have to have a pound of fructo-oligosaccharide (FOS) or guar gum (GG) before every meal. 8g per day will suffice to induce significant reductions in food intake and limit fat gain - at least that's what the most recent study from AgroParisTech says.
Impatience and the resulting inability / unwillingness to adhere to diet and lifestyle interventions to see results is one of the most important reasons people fail to lose body fat. Against that background it is important to put the results of pertinent study into perspective, not just in terms of what you can expect (dieting alone won't give you abs like those of the guys on the cover of fitness magazines), but also in terms of the time-frame over which the changes occur.

This is particularly important when we are dealing with rodent studies. While every SuppVersity reader knows that you must not translate the amount of supplements used in rodent studies 1:1 to humans (learn how it works), I must confess that I rarely highlight that the dosages that are used in rodent studies are not the only thing that must not be translated 1:1. The same goes for the time-scale, as well.
You can learn more about the fiber at the SuppVersity

Polydextrose & Res. Malto 4You

Most people don't get enough fiber

Foods, Not Ma- cros for the Gut

Fiber and Mortality Risk

Appetite Short News /Fiber

Xanthan as GI Reducer?
Let's take the latest study from the AgroParisTech as an example. In said study, Hadri et al. investigated the effects of fermentable dietary fiber such as fructo-oligosaccharide and viscous dietary fibers such as guar gum and alginate affect energy homeostasis in - you guessed it - rodents.

The subjects of the study, male C57BL/6J mice have a lifespan of roughly 750-820 days (max). So, if we assume an average lifespan of 111 weeks for rodents, the 3 week study would be 2.4 years long . in human terms that is (this is a hilariously inaccurate estimate, but I guess it'll serve its purpose).
Figure 1: Changes in adiposity and cumulative food intake over the whole study and during week 1 (Hadri. 2015).
So, even if you saw the exact same effects on food intake, body weight and fat accumulation (see Figure 1) as the mice did, it will take you significantly longer, before the addition of ~8-9g of fiber for (that's already the equivalent for human beings) in form of fructo-oligosaccharide (FOS) or guar gum (GG) would produce a similar substantial decrease in the development of adiposity (17% and 14%, respectively).

What appears to be independent of the time-span, though, is the fact that the same amount of fiber in form of alginate would not have any beneficial effects on your body fat levels - just as it didn't do anything for the adipose tissue of the "rodent subjects".
So, if you increase your fiber intake, keep in mind that this is no "quick fix"! Rather than that, it is one of many lifestyle changes the sum of which may help you to control your food intake and limit the storage of body fat.

Figure 2: A comparison with the cumulative food intake in week 1 (Figure 1, right) shows that the beneficial effects of increased fiber intakes vanish over time (Hadri. 2015). Against that background it's all the more surprising that there was still a significantly reduced increase in body fat in the fiber vs. no fiber groups towards the end of the study.
Now that we already speak of the effects, it may be worth mentioning that the often-cited beneficial effects of an increased fiber intake on food intake disappeared over the course of the study (see Figure 2). Against that background and in view of the fact that the increased fiber intake had no effect on the expression of appetite controlling proteins in the brain (POMC, CART, AgRP, NPY and MC4R mRNA) it is all the more surprising that the relatively small amount of fructo-oligosaccharide and viscous dietary fibers such as guar gum did have any effect on the accumulation of body fat. A "miracle" that may yet be explained by the results of a previous human study by Jill A. Parnell (2009) which found a lower area under the curve (AUC) for ghrelin (appetite decrease | P < 0.004) and a higher AUC for peptide YY (PYY | increased satiety) and 1kg fat loss after 9 weeks on oligofructose (P < 0.03) with significantly larger amounts of fiber (21g vs. 8-9g in the study at hand).

What the study at hand adds to the existing evidence is thus that (a) it takes patience to see the beneficial effects of fiber pre-loads and that (b) the amount of fiber that's necessary to elicit beneficial effects over the (really) long term may be much lower than the 20g+ previous studies suggested | Comment on Facebook!
  • Hadri, Zouheyr, et al. "Long term ingestion of a preload containing fructo-oligosaccharide or guar gum decreases fat mass but not food intake in mice." Physiology & behavior (2015).
  • Parnell, Jill A., and Raylene A. Reimer. "Weight loss during oligofructose supplementation is associated with decreased ghrelin and increased peptide YY in overweight and obese adults." The American journal of clinical nutrition 89.6 (2009): 1751-1759.