Science Daily’s New Fat Myth: Fat is Converted to Carbon Dioxide

An article appearing last week on the Science Daily website makes the outrageous claim that body fat is converted to carbon dioxide and water. This new fat myth is probably less harmful than many other myths associated with weight loss, but that is only because no one has come up with a way to monetize the belief that fat is converted to carbon dioxide in the body…yet.

The article in question, “When you lose weight, where does the fat go? Most of the mass is breathed out as carbon dioxide, study shows,” starts off with the statement: “The most common misconception among doctors, dieticians and personal trainers is that the missing mass has been converted into energy or heat.”

Unfortunately for Science Daily, that is exactly what happens in the human body when fat is metabolized:  the fat is converted into energy, so any article that starts off by rejecting that basic fact – that fat is not metabolized into energy – has already lost credibility.

The human body is a clever organism.  When you are eating normally, it takes in protein, carbohydrates, and sugars (which, of course, are complex carbohydrates), converts the protein into body tissue and converts the carbohydrates and other dietary sugars into the glucose that goes into the bloodstream and eventually passes into the body cells that burn the glucose to create energy.  So far, so good. When the body’s reserves of ready calories from blood sugar have been exhausted, usually during the overnight hours while we are sleeping, the body metabolizes fat into blood sugar and uses the blood sugar liberated from the fat through that process to provide fuel for the body.

Not so fast, according to the study’s lead author, Ruben Meerman, a physicist and Australian TV science presenter. “The correct answer is that most of the mass is breathed out as carbon dioxide. It goes into thin air.” That’s true, but it is also irrelevant to weight loss, and misleading because it suggests that body fat is converted into CO2 and H2O, but that’s not true.  The body breaks down the fat into glucose, and the glucose is turned into carbon dioxide and water as the energy in the glucose is used as fuel by the body.

Professor Andrew Brown, head of the UNSW (University of New South Wales)  School of Biotechnology and Biomolecular Sciences, who contributed to the study, has said that,”There is surprising ignorance and confusion about the metabolic process of weight loss.” That is certainly been proven true….by this article.

Science Daily isn’t actually a scholarly journal, although it masquerades as one.  It looks like the online version of a scholarly journal, but it carries advertising, something real journals never do and it is actually a compendium of press releases that are neither vetted by anyone nor peer reviewed. It is not clear whether they actually charge to publish press releases, but other online journals often charge an upfront fee to publish research reports, which does severe damage to their impartiality. Because Science Daily carries paid advertising, it is not likely that they are charging contributors to publish their articles; the articles justify their advertising rates by attracting traffic to their pages, and the advertisers pay the freight. The original article upon which the release was based was published by BMJ (British Medical Journal), which is a professional, peer-reviewed journal.

The bottom line on this story is simple.  Sometimes, a study really isn’t worth the effort and, in this case, there was really very little effort involved, since all this study does is reiterate known facts of very little use  to anyone embroiled in a weight-loss struggle.