Treatment of establishedobesity is a major public health challenge. Preventing excess weight gain has the potential to reduce the need for intensive and costly obesity treatment programs, yet few evidence based interventions or effective strategies exist. The World Health Organisation (WHO) has recommended that prevention of overweight and obesity in adults should include efforts to prevent further weight gain, even when body mass index (BMI) is still within an acceptable range. Clinical service providers and public health organisations are increasingly dealing with complex and costly obesity related health problems. Clinical guidelines for the management of obesity urge health care practitioners to deliver intensive, prescriptive interventions which increases demands on practitioners’ time.  Limited success in weight loss treatment suggests a target to prevent weight gain is a more realistic option, applicable to all population groups with potential for higher patient satisfaction, commitment and success.

Preventing weight gain requires just small changes to lifestyle behaviours that are easy to achieve for most people compared to the behaviour change required to achieve significant weight loss. The Healthy Lifestyle Program (HeLP-her)  is one of the first successful weight gain prevention trials in women which demonstrates  the annual weight gain experienced by many in the general population can be prevented. The low intensity program is at least as effective as more costly and more intensive lifestyle interventions, potentially providing long term clinical benefits. The intervention successfully prevented weight gain and positively changed weight-related behaviours in women. The HeLP-her trials have paved the way for prevention programs to be implemented which can be adapted for various settings and populations, particularly work-places, integrated with childhood obesity programs, environmental and systems change strategies and contribute to a multi-level approach to population obesity prevention.