For all of us who have tried and failed to help obese patients lose weight, the viewpoint by Proietto in this issue of the Journal offers some explanation for our defeat.
Overeating and low activity levels cause everyone to gain weight. However, the propensity to become obese is genetically predisposed, and expression of the genes involved may well be permanently up-regulated by early experience of overeating. When weight is lost, there are hormonal changes that favour weight regain. These factors make it very difficult for obese people to achieve significant and sustained weight loss with diet, exercise, medication or food replacement programs.
For this reason (and because studies of bariatric surgery have repeatedly shown significant long-term weight loss), Proietto calls for bariatric surgery to be made more widely available in public hospitals. This view has widespread support from many sectors of the medical profession. Bariatric surgery has generally only been available at high financial cost to patients, and, indeed, a lucrative private bariatric surgery industry exists. However, in Australia, as in other developed countries, highly processed food with low nutritional value and high caloric density is often cheaper and easier to prepare than more nutritious food, so obesity is more commonly a disease of the poor, who would need public funding to make bariatric surgery accessible.
Greater availability of gastric banding may well have some impact on the burden of chronic disease in our society. Proietto reminds us that significant weight loss is accompanied by a degree of reversibility of conditions that are common in obese people, such as diabetes, metabolic syndrome, obstructive sleep apnoea and infertility.
Nonetheless, as a public health measure and in the long term, bariatric surgery is unlikely to be our most effective approach to the obesity epidemic. It is time to look seriously at primary prevention, and Proietto’s discussion of epigenetics explains why this must start with maternal diet in pregnancy and infant feeding.
We have waited far too long for legislated public health measures that will improve the food intake of Australians. Clinical medicine doesn’t happen in a vacuum. Various legislative measures support the medical message to stop smoking and moderate alcohol intake. We need to be equally aggressive towards the obesity epidemic. This, of course, includes strategies to encourage regular daily exercise.
There is good evidence that self-regulation by the food industry has been ineffective. In a previous issue of the Journal, Hebden et al (Med J Aust 2011;195: 20-24) reported that junk food advertising during children’s peak hours of television viewing actually increased after self-regulation was introduced. We have previously debated the problems inherent in the National Heart Foundation Tick program (Stanton, Med J Aust 2011; 194: 284-285). It is important for food labelling programs to be transparent and universal. Many experts argue that sugar and fats are far too cheap, and should be taxed.
The government is already fighting the alcohol and tobacco industries. It is time to take on the processed food lobby as well.
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