Does Inulin Really Contribute To Loss Of Body-Weight?

Let us have a look at these fermentable carbohydrates; inulin in particular.

Altered gut microbial flora is increasingly being suggested as an important contributor to increase in fat mass leading to obesity (Backhed et al., 2004). This is true both in animals (Ley et al., 2005) and human beings (Ley, Turnbaugh, Klein, & Gordon, 2006).

“Fermentable” carbohydrates like inulin, guar gum and fructo-oligosaccharides – amongst others – sufficiently alter intestinal microbial flora to significantly retard the development of obesity.

Let us have a look at these fermentable carbohydrates; inulin in particular.

How does Inulin Supplementation lead to fat loss?

Fermentable carbohydrates like inulin (also, fructans and ?-glucan) – as their name suggests – undergo fermentation in the large intestine (Kleessen, Hartmann, & Blaut, 2001; Snart et al., 2006). Others like guar-gum and fructo-oligosaccharides improve the large gut micro flora by increasing the bifidobacteria and lactobacilli (Tuohy, Kolida, Lustenberger, & Gibson, 2001).

Synonyms frequently used for inulin are chicory root fiber or chicory root extract.

Although large-scale “industrial” production comes from chicory roots, inulin occurs in a wide variety of plants and has been a part of the human diet since time immemorial. Chemically, it is composed of a mix of linearly arranged oligofructose and polyfructose chains terminating in a glucose molecule (Sensus, 2013).

All of these fermentable carbs – by effectively improving the population of the beneficial colon bacteria – cause reduction in body weight by either increasing anorectic (hunger-suppressing) hormones or by inducing satiety (hunger-quenching) (Cani, Neyrinck, Maton, & Delzenne, 2005; Zhou et al., 2006; Zhou et al., 2008):

• Increase in peptide YY (Cani et al., 2005; Parnell & Reimer, 2009)
• Increase in glucagon like peptide-1 (GLP-1) (Cani et al., 2005)
• Suppression of plasma ghrelin levels (Arora et al., 2012)
• Induction of satiety (Vitaglione, Lumaga, Stanzione, Scalfi, & Fogliano, 2009; Kaji, Karaki, Tanaka, & Kuwahara, 2011)

Also, oligofructose-enriched inulin delays progression of obesity even when high fat diets are consumed regularly (Arora et al., 2012). When supplemented with inulin, both visceral and subcutaneous fat in male mice decreased significantly. Furthermore, adipocyte (fat cell) size was also shown to have been reduced (Arora et al., 2012).

Other studies have also reported similar findings even when high-fat diets have been consumed (Cani et al., 2005; Cani, Dewever, & Delzenne, 2004).

Dosage and Adverse effects associated with Inulin

As with other dietary fibers, lack of research means the doses for inulin supplementation have not been standardized.

Similarly, the side-effects or adverse-effects profile of inulin has also not been defined. However, some untoward effects that may occur, especially in those with sensitivity are:

• Intestinal upset – including bloating and gases
• Diarrhoea
• Increase in harmful intestinal micro flora
• Rarely, an anaphylactic reaction due to “food allergy reactions” may be encountered

Our Verdict on Inulin for Weight Loss

Although the effectiveness of inulin in causing weight-loss has been proven, it can be argued that much of the evidence comes from animal studies. Having said that, the suggested mechanisms (of inulin and other fermentable carbohydrates) to reduce adipose tissue do seem convincing.

Diet Pills Watchdog recommends the use of inulin as a dietary supplement. However, (given that there is lack of human evidence), it may or may not induce weight-loss.