The Institute of Fiscal Studies (IFS) in London has published a paper entitled: “The dietary
impact of the COVID-19 pandemic.”(1) They used a household level database that records all food and non-alcoholic beverages purchased in supermarkets by a nationally representative sample. Within that database was sub-set of data on food purchases for out-of-home consumption. These two datasets were combined to yield data on the types of foods purchased and their calorific value. Their statistical methodology goes above the head of this blogger but given the reputation of IFS, I am taking their findings as they stand. Their data were longitudinal so they could provide data for the entire period of the pandemic and relate such data to those of the previous non-pandemic year. The figure below outlines caloric intake in the home over the period of the pandemic.
In the weeks before the pandemic, calorie intake at home was comparable to the same period in 2019. Around 10 weeks later, there is a spike in purchases, probably reflecting stockpiling and panic purchasing. For the ensuing 20 weeks of lockdown, caloric intake at home was well above the comparable 2019 period, estimated at 30% higher. From about week 27 to week 39, restrictions were eased and in home caloric intake declined but was still above the comparable levels for 2019. Thereafter, as restrictions were re-introduced, in-home caloric intake began to rise again and at a rapid pace. The figure below shows the composition of the foods purchased. The purchase of fruits, vegetables and snacks remained fairly constant. There was a significant decline in ready-to-eat foods and a sharp rise in the purchase of ingredients, indicating a swing to home cooking.
There was a significant drop in food expenditure for dine-in restaurants and a significant rise in the purchase of takeaway foods. When in-home and out-of-home data is combined, net caloric intake rose. To directly quote the authors: “Over the period April to June, the impact of the pandemic on total calories was due to households increasing their at-home calories by more than the fall in their out-of-home calories.”
The next set of figures show how out-of-home purchases and calories changed
There was a significant drop in food expenditure for dine-in restaurants and a significant rise in the purchase of takeaway foods. When in-home and out-of-home data is combined, net caloric intake rose. To directly quote the authors:
“Over the period April to June, the impact of the pandemic on total calories was due to households increasing their at-home calories by more than the fall in their out-of-home calories.”
Finally, the authors examine how household composition influenced the net caloric increase in the pandemic:
Retirees showed the least change in caloric intake relative to 2019 with a graded extent of net caloric gain as household moved from those with low skilled employees (about 10%), through semi-skilled about (15%) and peaking with the highly skilled with an average rise of caloric intakes of 25%. (These calculations are my rough estimates from the above graph).
There are ample studies showing that periods of lockdown were associated with weight gain. For example, a 3-month showed very significant weight gain during lockdown : “During the lockdown period, greater pro-portion of women gained weight compared to men (46.1% vs 40.6%, P < .01). The obesity rate after the lockdown increased among women (40.7%-41.7, P < .01) but decreased among men (39.6%-38.6, P < .01) compared to before the lockdown”.
The problem with weight gain is that it always unintentional and if left unattended the weight gain will persist. There are lessons to be learned about food habits in lockdown and this paper makes a very important contribution to this area.
(2) Mulugeta W, Desalegn H, Solomon S. Impact of the COVID-19 pandemic lockdown on weight status and factors associated with weight gain among adults in Massachusetts. Clin Obes. 2021 Aug;11(4):e12453. doi: 10.1111/cob.12453. Epub 2021 Apr 14.
