Study Examines Holiday Weight Gain

How much weight is gained on average during the holiday season? It's a regular question received by registered dietitian nutritionists in the United States. For many Americans, the focus of holiday weight gain centers on the timeframe between Thanksgiving and New Year's Day. However, as RDNs continue to work with more diverse patients and clients and researchers look more at the relationships between various cultures and food, weight changes associated with other festive celebrations and in other countries will be important to consider.

A systematic scoping review, published in Current Obesity Reports, compared 23 observational studies, 10 controlled trials and six interventional studies looking at weight in healthy populations during various holidays over a 30-year time period. A majority of these studies were conducted in the U.S., and 70 percent found a significant increase in weight-related outcomes during festive periods that involved feasting. Although the mean weight gain was 0.7 kilograms, two of the studies associated this amount with more than half of the weight gained annually. One factor that was identified in driving weight changes was an increase in energy intake during festive periods compared to baseline. This was most notable during specific celebratory periods, including a 13 percent increase in energy intake around Thanksgiving, followed by a 36 percent increase between Thanksgiving and New Year's Day, compared to a 16 percent increase during Nowruz, the Persian New Year.

Other researchers analyzed weight gain trends after major celebrations, looking specifically at the United States, Germany and Japan and published their findings as correspondence in the New England Journal of Medicine. The study covered a 12-month period spanning from 2012-2013, where daily weights were collected from participants through wireless scales. A statistically significant increase in weight was observed in all three countries within 10 days following the Christmas holiday. A significant weight gain was also observed around other major celebrations specific to each country. During Golden Week in Japan, a 0.3 percent increase in weight was observed, whereas Easter in Germany and Thanksgiving in the United States both saw an increase in weight of 0.2 percent among their respective populations. The study did find that after the holidays, up to half of holiday weight gain was generally lost. However, the remaining weight gain was maintained by many individuals until the summer months and beyond.

Although the research on holiday weight gain is not extensive, several studies have also focused on weight loss interventions during the holiday season. A study published in Obesity Research & Clinical Practice in 2019 looked at active duty military personnel based in Texas who had a body mass index of 26 or greater. Participants, who were categorized based on self-reported race (i.e., African American (19.8%), Caucasian (65.7%), or "other" (14.5%)) and ethnicity ((i.e., Hispanic (77.4%) or Non-Hispanic (22.6%)), joined on a rolling basis throughout the year and were provided with electronic scales, then encouraged to take daily self-weights. Weight change and frequency of weighing behavior was compared between subgroups of participants. They were also categorized into three groups: those who joined prior to the holiday season (between October 1st-November 14th), during the holiday season (November 15th-January 1st) and after the holiday season.

Although differences in the rate of weekly weight changes were noted throughout and by race, there was not a significant weight change between pre- and post-holiday weight status amongst the study participants. Further analysis showed that those who joined the study during the holiday period were more likely to continue with daily self-weights and lose weight whereas those who had joined prior to the holiday season were apt to weigh less frequently and more likely to gain weight.

Weight loss maintenance and self-monitoring were additional topics of interest to researchers who initiated a 2020 pan-European study of adults in the United Kingdom, Denmark and Portugal. Participants were recruited if they had experienced at least a 5-percent weight loss within the past year (verified through medical records) and previously had a BMI greater than or equal to 25kg/m2 prior to losing weight. During the 18-month study, twice weekly weights were collected via smart scales and trends in body weight fluctuations were evaluated. Over the Christmas period, weight increased by a mean of 1.35 percent. It decreased again between January and March but remained at least 0.35 percent higher than before the holiday season. Although weight gain was observed among groups from all three countries, those from the UK gained significantly more compared to those in Portugal (P=0.011), indicating the potential for cultural differences towards food and eating behaviors during the holiday season.

Although individual weight changes may vary, the reference ranges observed in these studies have been smaller weight fluctuations than the 10 pounds many people claim they have gained after the holiday season. However, these studies also indicate that many individuals do not lose the weight they have gained during the holidays either. Registered dietitian nutritionists can help patients and clients reframe their relationship with food during the holidays and help them to meet their goals in achieving a healthy and balanced lifestyle.

References:

• Zorbas C, Reeve E, Naughton S, Batis C, Whelan J, Waqa G, Bell C. The Relationship Between Feasting Periods and Weight Gain: a Systematic Scoping Review. Curr Obes Rep. 2020 Mar;9(1):39-62.
• Helander EE, Wansink B, Chieh A. Weight Gain over the Holidays in Three Countries. N Engl J Med. 2016 Sep 22;375(12):1200-2.Fahey MC, Klesges RC, Kocak M, Wang J, Talcott GW, Krukowski RA. Do the holidays impact weight and self-weighing behaviour among adults engaged in a behavioural weight loss intervention? Obes Res Clin Pract. 2019 Jul-Aug;13(4):395-397.
• Turicchi J, O'Driscoll R, Horgan G, Duarte C, Palmeira AL, Larsen SC, Heitmann BL, Stubbs J. Weekly, seasonal and holiday body weight fluctuation patterns among individuals engaged in a European multi-centre behavioural weight loss maintenance intervention. PLoS One. 2020 Apr 30;15(4).