Animal study: hydroxypropyl methylcellulose reduces fat mass but boosts muscle growth

A product that the food industry has been using for years as a filler and gelling agent is, according to American researchers, a body recompositioning drug. They will soon publish the results of their animal study that their assertion is based upon in Obesity.

The Americans work at the University of Minnesota and with the supplements maker Imagenetix []. So maybe this study won’t disappear into a library, but stimulate the generation of new slimming products. This may well be the case, for recent research has shown that hydroxypropyl methylcellulose [HPMC] is one hundred percent safe. [ 31-7-2007]

Hydroxypropyl methylcellulose, or E464, is also sometimes called hypromellose [structural formula shown below]. Manufacturers make the stuff from cellulose. It is one of the ingredients in many medicines. HPMC dissolves in the stomach and forms a sticky gel. This delays the speed with which medicines pass through the gut, therefore increasing the uptake of active ingredients in the medicine. So if you put an amino acid in a tablet containing HPMC you've made a time-release supplement. It's as simple as that.

The gel-forming property also makes HPMC interesting for food manufacturers who make bars for example. []


In 2010 the European Food Safety Authority rejected an application from a company that wanted to add HPMC to products that stimulate the gut. [EFSA Journal 2010;8(10): 1739.]

The American researchers were curious to know whether it's possible to add HPMC to slimming products. Much research has been done on the slimming effects of many types of fibre, mostly with little success, but HPMC had never been studied before.

The researchers gave half of a group of rats food containing 5 percent HPMC for a period of six weeks. A control group were given food consisting of 5 percent cellulose.

The weight of the rats in the HPMC group increased more slowly than the weight of the rats in the cellulose group. The soluble fibre resulted in a decrease in fat mass and – even more interestingly – an increase in lean body mass.

HPMC boosted the activity of AMPK in the muscles. AMPK is a sensor that tells cells that they need to burn more fats, give more priority to repair processes and to absorb more glucose from the blood.

The study doesn't reveal exactly how HPMC works; the mechanism is still a puzzle. The researchers say more and longer studies need to be done.

Obesity (Silver Spring). 2011 Nov 17. doi: 10.1038/oby.2011.341. [Epub ahead of print].