The Carb-Sane Asylum

A while back I listened to an interview with Steven Guyenet of Whole Health Source blog where he mentioned a study where the gut bacteria were transplanted from obese mice to normal mice that had no endogenous bacteria.  The normal mice gained more weight.  Microflora differences have been identified between normal and obese humans and normal and anorexic humans.   This has led to much speculation that changes in microflora could be a causative agent in obesity. This is one such study:    An obesity-associated gut microbiome with increased capacity for energy harvest I look at such studies and consider them to be interesting, but of all the alternate theories out there, I'm probably most skeptical of this one as being a significant  cause  of obesity.  I'll deal with the energy balance aspects and some related math in future post.   This post will focus on the differences between rodent and human digestion that lead me to believe th...

I believe that, like sugar alcohols, soluble dietary fiber should be counted on a 0.5g carb/gram fiber basis.  However since most dietary fiber is not listed as to whether it is soluble or insoluble, this can be difficult to do.  Erring on the side of caution, a 1g for every 3g total dietary fiber would be a good compromise.  But many of the LC "fibers" such as polydextrose, inulin and glucomannan (shiritaki noodles) are essentially all soluble so 1g counted for 2g is a better count. In soluble dietary fiber, IDF, passes through the human digestive system unchanged so it is non-nutritive in all aspects. Further, since it adds bulk to food and assists in stool formation and "moving things along" IDF can reduce the nutrient absorbtion from the food we do eat.  This is essentially the rap of the "fiber is overrated" contingent. SDF may not be metabolized by the body, but it is fermented by intestinal bacteria to short chain fatty acids (SCFA...