I spotted two articles about weight gain during lockdown and it prompted me to do a systematic search for evidence on this topic. Given that lockdowns are such new interventions, a surprising number of studies, from many different countries, have already been published.
The studies that caught my eye were one from the US and one from Switzerland. The US study was by Seal et al and it was called "COVID-19 pandemic and stay-at-home mandates promote weight gain in US adults" (Ref 1). The Swiss study was by Maggio et al and it was called "Evaluation of the Impact of the COVID-19 Lockdown on BMI in Children and Adolescents with or Without Obesity" (Ref 2).
The conclusion of the US study was “US adults gained weight, and stay-at-home mandates were associated with atypical weight gain and greater reported weight gain in individuals with obesity over 3 months.” The conclusion of the Swiss study was “The COVID-19 lockdown had a negative impact on the BMI of youth with obesity.” One study addressed adults; the other children and adolescents. Both found that lockdowns were associated with weight gain and both found that people who were already obese gained more weight than those of normal weight.
Let’s look at the systematic review to see if these findings were generally supported and if any other findings have been made.