Where does the weight actually go when you lose it?
KEEN to shift some of those kilos packed on during Christmas indulgence? A Bundaberg scientist has done the maths that shows there's a limit to how much and how quickly you can lose it - and he's attracting worldwide attention for his work.
THIS is not your average amazing weight-loss story.
Ruben Meerman didn't tip the scales at a gazillion kilograms. There are no post-weight-loss photos holding his former fatty pants, into which he could now fit two of himself.
The 43-year-old simply lost 15kg in the first half of 2013 after being disturbed by his "fat gut" in a photo, gradually shedding the weight by counting kilojoules, setting a target and walking for an hour and a half each day.
Where Meerman's story differs is here: when he first hopped on the scales and noted his weight loss three months in, he did more than just celebrate the small achievement.
He asked himself the question: "Where does the weight actually go when you lose it?"
It wasn't an idle question for someone like Meerman, a physicist who did most of his growing up in Bundaberg and who later made a name for himself as an innovative touring science educator in schools and as an ABC TV and radio presenter known as the "Surfing Scientist".
"I was working on a kids' book - which I still haven't finished - and while I was reading up for that, I was reading about the digestive system, farts, poos, guts ... you know, all the stuff kids like," he said with a laugh.
"I realised none of the fat I was losing was coming out of my butt, but my lungs. And I thought that was the most interesting thing I'd read in ages, so I did a lot more reading about it."
Meerman's understanding of physics told him the weight couldn't just vanish. That would violate the Law of the Conservation of Mass (which says matter can't be created or destroyed, only transformed into other substances).
And it was well-established biochemistry that fat was broken down into carbon dioxide (CO2) and water (H2O) - even if he discovered with some alarm that the majority of health professionals and weight-loss practitioners believed it was "burnt off" as energy or heat.
But he wanted to determine what exact proportions of the mass in fat turned into CO2 and H2O, and even a string of biochemists couldn't help him do that.
"Before I came along with this maths, biochemists weren't really interested in the waste products of fat metabolism - just in the energy that comes out of it," Meerman said.
By July 13 he had nailed a complex calculation that said, in simple terms, 84% of fat became exhaled CO2 and 16% became water (for instance, urine, faeces, sweat, tears or other bodily fluids).
There was an important practical ramification of his calculations - for ordinary people who wanted to lose weight while still eating three meals daily, there was a limit to weight loss of about 70-100g per day, depending on kilojoule intake and physical activity.
"That's about half a kilo a week or 15kg in six months. Anybody attempting to lose more in that amount of time is destined to fail because you simply cannot do it," Meerman said.
Meerman presented his figures for the first time at a TEDx conference at Brisbane's QUT in August 2013, and in March last year, he filmed an episode for the ABC's Catalyst program focusing on his work.
That turned out to be fateful, because the episode brought him into contact with Professor Andrew Brown, Head of the School of Biotechnology and Biomolecular Sciences at the University of NSW.
Prof Brown later suggested they work together to publish a peer-reviewed paper on what he thought was a fresh take on weight loss, and, as Meerman puts it, a scientific "bromance" blossomed.
It was much more than that. The pair's paper was accepted for publication in the prestigious BMJ (formerly the British Medical Journal) - not a bad first effort for someone who had largely built his reputation on being the dude in the boardshorts who blew stuff up.
Since the article was published just before Christmas, it has attracted interest from around the world, leaving Meerman a little overwhelmed by the attention but also feeling vindicated.
"There are so many people close to the weight-loss industry and the obesity crisis who are ignorant about the process of weight loss," he said.
"I've gone back to basic chemistry that was discovered 100 years ago, yet this is blowing people's minds."
The future looks bright for the affable physicist, who stoked his love for science while he was a student at Kepnock High School.
He's working towards both a book and a PhD focusing on his findings, and he has big plans to take on the bogus weight-loss industry and ensure his and Brown's work makes its way into the science curriculum.
"I really value teachers, but we have a science education crisis in Australia," Meerman said.
"Kids think it's boring and that breaks my heart, so I'm hoping this huge gap I've uncovered in basic science knowledge among health professionals and laypeople alike will make policy makers sit up and take notice.
"I do science demos for a living but I'm on a mission to put myself out of a job. Any teacher can do what I do and hopefully, one day, they all will."
SOME THINGS YOU MIGHT NOT HAVE KNOWN ABOUT FAT
- Pure beef fat contains about 3700kJ/100g, while pure carbohydrate (such as white sugar) and pure protein contain about 1700kJ/100g.
- Boiled potato contains about 250kJ/100g, but potato chips rocket up to 2300kJ/100g because of the fat in the manufacturing process.
- You lose weight overnight, thanks mostly to the carbon dioxide you breathe out.
- The average person excretes 33mg of carbon dioxide in every breath they exhale.
CLEARING UP THE CONFUSION
The two most common misconceptions about Meerman's work are:
1. You can lose weight just by breathing in and out a lot more.
Sadly, no. That would be hyperventilating, and you would probably faint.
That process of metabolising stored fat is actually a complex series of steps involving dozens of enzymes, which firstly liberate fat molecules stored away in fat cells and then eventually break it down into carbon dioxide and water - and things like exercise and, in turn, being hungry increase the production of those enzymes.
2. If fat is lost largely through exhaling carbon dioxide, losing weight must exacerbate global warming.
Again, no. The carbon dioxide (CO2) we breathe out is simply reformed at a molecular level from the carbon, hydrogen and oxygen atoms that all make up the fat, protein and sugar we eat, and it was only consumed from plants and animals a short time ago.
Global warming happens when we unlock the carbon atoms stored in ancient fossilised forests, or huge deposits or dead phytoplankton buried deep underground. Left untouched, things such as coal and oil would remain inert. Dig it up and burn it, and that's when you release the greenhouse gases that contribute to climate change.