The key to preventing obesity in future generations is to make their parents healthier before they conceive, leading health researchers suggest.

In a series of papers, published in The Lancet Diabetes and Endocrinology, the researchers say that the time before couples conceive represents a missed opportunity to prevent the transmission of obesity risk from one generation to the next. They argue that a new approach is needed to motivate future parents to live a healthier lifestyle.

There is now a wealth of evidence that the risk of obesity and its associated conditions, such as heart disease diabetes and some cancers, could impact the developing baby. In turn, when the child becomes a young adult they may pass the risk of obesity on to their children - it is a vicious cycle.

The nature of this problem is not adequately appreciated. Many young people, whilst appearing outwardly healthy, are nonetheless on a risky path to obesity and chronic disease and more likely to pass this risk to their children, the researchers warn. Many pregnancies are unplanned, and the special needs of adolescents and young people at this important time are not sufficiently recognised. Far from helping them to prepare and plan for pregnancy and parenthood, many public health programmes assume that their needs are similar to the general population and require no special measures or provisions.

In a comment piece accompanying the research papers, Professor Mark Hanson of the University of Southampton, says an entirely new approach is needed that engages parents-to-be and encourages them to be part of the solution.

"The approach needed is both top-down and bottom-up, but even more importantly requires something in between which young people can help to create themselves," Professor Hanson writes.

"If at present many young people do not seem to care about their health or view it as a low priority, perhaps they have not been given clear information about what they can do to optimise their health for themselves and their children. All societies owe their adolescents the chance to make their future healthier. Additionally, the political leaders who have committed to the new Global Strategy for Women's, Children's and Adolescents' Health must give adolescent health priority in national health strategies, plans, and budgets. Only these actions will enable the transformation required."

The Lancet Diabetes and Endocrinology series on Maternal Obesity was launched at the Power of Programming 2016 conference in Munich today (13 October)..

Each of the four papers in the Series tackles a different aspect of the challenge. The first paper (Poston et al.) explores trends in the global prevalence of obesity among women and the adverse consequences for their reproductive health and the outcome of their pregnancy, especially in those countries least able to accommodate associated health-care costs. The authors call for larger studies to determine the scale of complications in these countries, which may not be prepared to manage the increasing burden on healthcare resources, and for an international drive to reduce obesity in women of reproductive age.

The second paper (Ma et al.) focuses on the clinical management of women with obesity, especially during pregnancy when the risks of conditions such as pre-eclampsia, high blood pressure and gestational diabetes are major concerns. There are also consequences for the baby, with greater risks of stillbirth, obstructed labour and congenital abnormalities. Clinicians are increasingly realising that the problems of obesity can manifest even in early pregnancy, again directing attention to addressing the problem before conception and between pregnancies.

The third paper (Godfrey and Reynolds et al.) explores the range of effects that maternal obesity can have on the child including greater adiposity (fat tissue), increased risk of allergies and effects on brain and behavioural development, such as autism and ADHD. The authors discuss the results of studies into the mechanisms linking maternal obesity to these adverse outcomes in their children, particularly epigenetic processes by which aspects of parental (both mothers and fathers) lifestyle can affect the way the baby's genes operate during development. These can change the person's responses to the challenges of, for example, living in an 'obesogenic' environment.

The final paper (Hanson et al.) suggests that the focus of interventions needs to be redirected to the preconception or post-partum periods of parents' lives. This requires a top-down approach from policy makers and service providers to improve the opportunities for young people, especially those in at risk groups, to lead healthier lives. But this alone may not be enough, the experts say. In addition, there is a need for a broader social movement that generates bottom-up mobilisation of communities and individuals, to create a demand for such services and opportunities. Engaging future parents in leading healthier lives will not only promote their health later, but will give their children a healthier start to life.