One quarter of Australian adults are obese. It is a sad stereotype that it is because they are weak-willed, over-indulgent and lazy.
In a new three-part documentary, The Obesity Myth, experts attempt to dispel such myths and the many stigmas weighing on the overweight.
“The obesity myth is that it’s all due to lifestyle,” says international obesity expert Professor Joe Proietto, the head of Austin Health’s Weight Control Clinic in Melbourne. “In fact, obesity is predominantly genetic.”
In fact, genes that evolved to help us are now contributing to a growing epidemic.
How? During times of inevitable famine, our body’s hormones changed to slow down our metabolism and help us store what weight we had for survival.
“All these genes were selected for evolution because they’re protective when you don’t have enough food, it’s only lately that we’ve had plenty of food,” Proietto says.
So simply eat less, right? Exercise some discipline and discipline yourself to exercise?
Not exactly. Eating less, eating better quality foods and exercise are important for everyone’s health, overweight or not. But, this is also where the obesity issue gets complicated.
About 90 per cent of the population is predisposed genetically to being overweight and obese and those with the “obesity” gene are about 70 per cent more likely to be obese.
Some epigenetic triggers (a high-energy, poor diet early on and malnutrition or over-nutrition in the mother while she’s pregnant) also make obesity more likely in certain people.
Despite this, experts agree that improving your diet and incorporating exercise will result in weight-loss.
“No matter what your gene is, if you don’t eat, your body will keep burning energy and you will lose weight,” Proietto says. “The problem is your genes make you hungry.
“Back then it made sense to do energy reduced diets – we didn’t know about these [hormonal] changes, we didn’t know a lot of what we know today.”
Two studies have influenced the two-part process he now uses to treat his patients.
The first study found that obese people could lose weight rapidly on a very low energy diet, using meal replacements for two of their three daily meals (the third carb-free meal consisted of protein, non-starchy vegetables and “a bit of oil or a bit of fat each day to empty the gall bladder”).
“We were testing whether it’s true that the quicker you lose it, the quicker you put it on and the answer is ‘no, it’s not’ it’s a myth,” he says.
Those on the very low energy diet had greater weight-loss “success” Proietto says, which he attributes to the motivation of seeing the weight fall away and that the plan was carb-free.
“Our diet is ketogenic – ketones are breakdown products of burning fat, they’re made by the liver and they take away hunger very nicely by acting on the brain,” he says.
Once the person has lost the desired weight and returns to whole foods (including carbohydrates), the hormonal changes make maintaining that weight near impossible.
“Our other paper, which we published in 2011, showed that the hormone changes you get with weight-loss are long-lasting,” Proietto says. “So following weight-loss you get an increase in the hunger hormone ghrelin and you get a decrease in several of the hunger-suppressing hormones. They don’t go back until you regain all the weight.”
For this reason, Proietto now puts his patients on life-long medicines to maintain the weight-loss.
“While we don’t need medication to lose weight, we think that maintaining weight really does require medication,” he says. “This is what makes obesity a chronic condition.”
Not all experts agree with Proietto that lifelong medication is necessary or that rapid weight-loss is the best approach.
Dr Nick Fuller, an obesity researcher from the Charles Perkins Centre at the University of Sydney, says the way the weight is lost determines its sustainability.
In his new book, Interval Weight Loss, he states that losing weight very slowly (no more than two kilograms in a month eating whole foods, focusing on sleep and exercise and then maintaining that weight-loss for a month before the next cycle) gives the body time to adjust and redefines the body’s set-point, meaning we do not trigger the hormonal cascade effect and decrease in metabolism.
“[Experts] acknowledge the weight keeps coming back and they say ‘OK, well the long-term solution is that we put them on medication or give them surgery’. You can’t do that – it’s garbage,” says Fuller, who is not involved in the documentary.
“You’ve got to do it slow and steady. Not everyone is going to get back to a normal weight – some will go from obese to overweight, but it’s a better result than losing 20 and putting 22 back on.”
While the methodology for dealing with the issue differs among experts and researchers, they all agree obesity is a big problem and that suggesting people just need to be more disciplined shows how largely it is misunderstood.
“I would like people to stop abusing people who are obese,” Proietto says. “It’s very difficult. People say even if they’re hungry they could choose not to eat, it’s bunkum, I would really like it if people weren’t abused for being overweight.”
The three-part documentary series The Obesity Myth airs Mondays at 7.30pm from September 4 on SBS.