The best kind of scientific paper is one that really makes one think. A recent paper in the New England Journal of Medicine from Jo Proietto’s group in Melbourne does just that. As an individual who has lost a lot of weight on several occasions, only to put it back on over two or three years each time, I know the challenge of sustaining weight loss, and given that metabolic disease is the area of my own research, if anybody should be motivated to keep weight off it should be me! I have no problem losing weight — I just have to get obsessive about diet and exercise — but sustaining that motivation proves almost impossible.
Jo’s group has studied the hormonal changes in individuals who have undergone a successful intensive weight loss programme in which they lost 10% of body weight. But a year later, while they had still maintained most of their weight loss, their hormonal profile and hunger tests showed that they had an even greater drive to eat than they had before they went on the weight loss programme.
The nature of the hormonal changes suggested that it was changes in the hormones from the stomach and fat that were driving this strong urge to eat. In a sense this study validates what some of us know: it is bloody hard to keep weight off. But it is actually saying much more than that. It is suggesting that in adults other approaches such as surgery and medications may be much more fundamental to sustaining weight loss than many would appreciate. It is also saying that the obesity epidemic is not just about how we live our lives as adults, but that underneath are some drivers that I suspect arise much earlier in life.
While we need to understand much more, an increasing amount of research including that from Mark Vickers and Bernie Breier from the Liggins Institute (Bernie is now a Professor at Massey University at Albany) suggests that appetite control and other aspects of metabolic control are set early in life — both before birth and in the few years after birth.
Other work from the Liggins Institute and overseas points to the probability that what parents do prior to conception, how a mother eats during pregnancy and how the infant is fed all have lasting effects on appetite control and the propensity to obesity. Slowly, the focus of attention in dealing with the obesity epidemic is shifting to a whole of life approach. Clearly the healthier we eat and the more we exercise as adults the better we will do, but Jo’s work really shows how problematic it is to deal with this problem once it has emerged. It challenges a lot of widely held conceptions and encourages a broader range of possible solutions to a major problem.
Now that is what impactful research is really about.