Change in weight category among youth early in the COVID-19 pandemic.

Remote learning and shelter-in-place orders during the COVID-19 pandemic are associated with obesity risk factors such as decreased physical activity, altered routines and sleep schedules, increased screen time, and non-nutritious food choices. The objective of this brief report is to describe change in weight category 3-6 months after the onset of the pandemic in a cohort of 4509 low-income youth. Inclusion criteria were youth aged 2-17 years with weight and height measure in a large primary care network between 1 January and 30 March 2020 (Q1), designated as pre-COVID period; and 1 June-30 September 2020, (Q3), as early-COVID period. Change in weight category was assessed between Q1 and Q3. Adjusting for visit type and time lapse, logistic regression was conducted to examine the association between weight category change and age, sex, and race/ethnicity. The proportion of youth with overweight or obesity increased from 37.8% to 44.6%; and declined by 5.6% in the healthy weight category. Over the 3-6 month period, 23.1% of youth gained ≥5 kg, 4.3% gained ≥10 kg, and 17.8% increased their BMI by ≥2 units. Among underweight youth, 45.3% switched to the healthy weight category, with a median weight gain of 2.1 kg (interquartile range [IQR] = 2.1 kg). Median weight gain was highest among those youth with severe obesity (5.8 kg, IQR = 5.2 kg). Younger age (2-9 years), female and ethnic-minority youth were more likely to change to a higher/worse weight category. Significant weight gain occurred in the first 3-6 months of the pandemic among low-income youth, reflecting the short-term effects of the pandemic.