The relationship between feasting periods and weight gain
A systematic scoping review examining the impact of festive feasting on obesity rates.
The current obesity pandemic has been primarily driven by unhealthy food environments biased towards heavily processed, energy-dense, nutrient-poor (EDNP) foods and beverages . The abundant availability, low prices and constant marketing of these foods  have led to overconsumption, which has become socially accepted in most high-income countries.
Traditionally, festive periods such as New Year, Christmas and Thanksgiving would not have contributed to population overweight and obesity because food was scarce for most people and feasting was the domain of those with prestige, power and social status . Today, far more people have access to EDNP foods and beverages over extended festive periods, which may contribute to population weight gain [1, 4]. The targeted marketing of EDNP foods and beverages (including alcohol) for festive periods and celebrations can also emotionally bind these unhealthy items to happiness and pleasure in our minds . With increasing globalisation and multi-culturalism, populations are able to engage with a broader range of national, cultural and religious celebrations, further increasing the exposure to EDNP foods and beverages and opportunities for their consumption.
While evidence indicates that weight gain occurs over holidays, the contribution of specific festive periods and celebrations to eating behaviour and weight gain is unclear. Led by Christina Zorbas from the Institute for Health Transformation’s Global Obesity Centre, the researchers aimed to synthesise the literature on how festive periods and celebrations contribute to population weight gain and weight-related outcomes.
They conducted a systematic scoping review to examine the relationship between festive periods and celebrations and population weight gain and weight related outcomes. A total of 39 studies were systematically reviewed, with a large proportion indicating significant increases in weight during festive periods and/or celebrations. The small proportion of interventional studies included in the review showed that weight gain could be reduced using self-weighing/self-monitoring and intermittent fasting approaches. Interventions targeting festive periods could have a significant impact on population weight gain. The scalability and sustainability of such interventions require further investigation, as do the broader socioecological factors driving unhealthy eating during festive periods.
Even though it is may appear obvious that festive periods and celebrations are associated with increased provision of EDNP foods and beverages, the limited literature quantifying the impact of this on weight gain, and the factors that influence it, is concerning. The absence of qualitative studies exploring the lived experiences of individuals during festive periods and celebrations, and leverage points for creating healthier festive and celebratory environments, is also somewhat surprising but highlights an area for future research. It would appear as though unhealthy eating and weight gain during festive periods and celebrations represents the status quo, even among researchers, to the extent that festive food environments have not been sufficiently challenged to date or determinants interrogated enough to offer solutions . As such, few national dietary guidelines advise on how healthy eating can be promoted in festive and feasting environments .
Minimal evidence was identified to inform policy actions to promote healthy eating and ameliorate weight gain over festive periods and celebrations but it’s likely that evidence-based actions to promote healthy food environments across governments, workplaces, schools and communities will be important, including the implementation of widely endorsed structural obesity-prevention policies such as marketing restrictions  and fiscal policies . Given the associations between festive feasting celebrations and unhealthy foods and beverages, these policies may need to be strengthened and tailored at these times of the year.
In terms of the research priorities stemming from this review, there is a clear need for longer term studies of the impact of feasting during festive periods on weight gain.
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