Factors associated with weight gain during the COVID-19 pandemic.

BACKGROUND: To limit transmission of COVID-19, state governments issued shelter-in-place orders. These orders coincided with a decrease in daily step count and an increase in overeating. We evaluated factors associated with weight gain of ≥ 15 pounds during the pandemic within an integrated health care system.
METHODS: We included adults ages 18 and above with at least one weight measurement before the pandemic (March 19, 2019-March 19, 2020) and another measurement after COVID-19 vaccines became available, more than 9 months into the pandemic (December 14, 2020-December 14, 2021). Logistic regression was used to identify factors associated with weight gain of 15 pounds or more.
RESULTS: Of 524,451 adults included in the study, median age was 61 years, 43.2% were men, 36.2% self identified as White, 8.6% Black, 35.7% Hispanic, and 16.2% Asian. During the pandemic, 38,213 (7.3%) adults gained ≥ 15 pounds. A higher proportion of young adults gained weight (16.2% age 18-39, 7.6% age 40-64, 4.7% age 65-79%, and 3.1% age ≥ 80). No significant difference was observed between men and women (7.2% men and 7.4% women). Weight gain was more prevalent among adults from low-income neighborhoods (8.9% low-income neighborhoods, 8.0% intermediate-income neighborhoods, and 6.5% high-income neighborhoods). Multivariable logistic regression demonstrated that compared to adults ages 65-79 years, young adults ages 18-39 years had the highest risk of gaining ≥ 15 pounds (adjusted OR 5.19, 95% CI 5.01-5.38). Black race was associated with weight gain in an unadjusted analysis (OR 1.25, 95% CI 1.21-1.30). However, this association was significantly attenuated after adjusting for other risk factors including neighborhood income levels (adjusted OR 1.06, 95% CI 1.02-1.10). Having a diagnosis of depression pre-pandemic was also associated with weight gain during the pandemic (adjusted OR 1.54, 95% CI 1.50-1.58).
CONCLUSION: In this racially and ethnically diverse population in southern California, significant weight gain of 15 pounds or more was observed in 7.3% of the adult population during the COVID-19 pandemic. Young adults, individuals who resided in low-income neighborhoods, and patients with depression were disproportionally affected.

Introduction

To prevent the spread of coronavirus disease 2019 (COVID-19), shelter-in-place orders were implemented across the United States. These orders, unintentionally, made it difficult for some people to maintain healthy lifestyles. Lockdown restrictions coincided with an observed reduction in physical activity, poor eating habits, and increased rates of depression and anxiety [1], [2], [3]. Suboptimal lifestyle changes contributed to weight gain during the COVID-19 pandemic [4]. In the United States, there are significant racial and ethnic disparities in obesity burden [5]. Individuals of low socioeconomic status living in disadvantaged neighborhoods are particularly vulnerable to weight gain due to the lack of safe outdoor spaces and healthy food options [6]. The COVID-19 pandemic and its disproportionate impact on individuals of low socioeconomic status may have widened already existing health disparities. Identifying populations at highest risk of unhealthy weight gain allows states to target their resources and intervention efforts. The goal of this study was to investigate factors associated with weight gain of 15 pounds or more during the COVID-19 pandemic in a racially and ethnically diverse population in the United States.

Methods

In this longitudinal, population-based cohort study, we included adult members (≥ 18 years old) of Kaiser Permanente Southern California (KPSC), an integrated health care delivery system in California. We included all adults who had at least one documented weight in their electronic health records before the start of the COVID-19 pandemic shelter-in-place orders (3/19/2019–3/19/2020) and at least one documented weight after COVID-19 vaccines became available (12/14/2020–12/14/2021). Self-reported race and ethnicity information was obtained from electronic health records. Medical comorbidities were identified using International Classification of Diseases, 10th Revision, codes. The Elixhauser Comorbidity Index was used to assess baseline medical comorbidities [7]. Socioeconomic status was measured based on median household income at the census tract level according to individual’s address of residence. Multivariable logistic regression analysis was used to identify factors associated with ≥ 15 pounds of weight gain. Odds ratios (OR) and 95% CIs were calculated. Analyses were performed with STATA 14 (Stata-Corp, College Station, TX). A 2-sided P < 0.05 was used to define statistical significance.

Results

A total of 524,451 adults were included (43.2% men, median age 61 years). Table 1 shows the baseline characteristics of the cohort. The cohort is racially and ethnically diverse, with 36.2% self-identified as White, 8.6% Black, 35.7% Hispanic, and 16.2% Asian (Table 1). During the pandemic, 38,213 (7.3%) adults gained ≥ 15 pounds. A higher proportion of young adults had weight gain of 15 pounds or more (16.2% age 18–39, 7.6% age 40–64, 4.7% age 65–79, and 3.1% age ≥ 80). Weight gain of greater than 15 pounds was observed in both men and women (7.2% men and 7.4% women). Weight gain was more prevalent among adults from low-income neighborhoods (8.9% low-income neighborhoods, 8.0% intermediate-income neighborhoods, and 6.5% high-income neighborhoods). A higher proportion of individuals with one or more chronic medical conditions experienced weight gain (5.9% among individuals with no medical comorbidities compared to 9.8% among individuals with ≥ 6 medical comorbidities).

Table 1

Baseline characteristics.

	Weight gain < 15 lbs(n = 486238)	Weight gain ≥ 15 lbs (n = 38213)	P value
Age a, median (IQR), y	61 (50, 71)	53 (39, 64)	<0.001
18–39	49898 (83.8)	9642 (16.2)	<0.001
40–64	235818 (92.4)	19344 (7.6)
65–79	165214 (95.3)	8103 (4.7)
≥ 80	35308 (96.9)	1124 (3.1)
Sex
Male	210288 (92.8)	16266 (7.2)	0.01
Female	275950 (92.6)	21947 (7.4)
Race or ethnicity b
White	174084 (92.1)	15013 (7.9)	<0.001
Black	40408 (90.3)	4362 (9.7)
Asian	82220 (96.9)	2634 (3.1)
Hispanic	173849 (92.1)	14985 (7.9)
Other	15677 (92.8)	1219 (7.2)
Income, $
Less than 45000	39717 (91.1)	3888 (8.9)	<0.001
45001–80000	185922 (92.0)	16280 (8.0)
More than 80000	260599 (93.5)	18045 (6.5)
Comorbidities
Hypertension	225502 (93.4)	16047 (6.6)	<0.001
Diabetes	118546 (93.5)	8201 (6.5)	<0.001
Coronary artery disease	35205 (93.3)	2548 (6.7)	<0.001
Heart failure	16065 (90.1)	1770 (9.9)	<0.001
Atrial fibrillation	20397 (92.3)	1701 (7.7)	0.016
CVA/TIA	18006 (92.3)	1511 (7.7)	0.013
COPD/Asthma	85120 (91.2)	8178 (8.8)	<0.001
Hypothyroidism	58981 (93.0)	4473 (7.0)	0.014
Chronic kidney disease	62045 (93.2)	4498 (6.8)	<0.001
Liver disease	33169 (91.7)	2989 (8.3)	<0.001
Rheumatologic disease	14001 (92.1)	1207 (7.9)	0.002
Depression	80674 (89.3)	9682 (10.7)	<0.001
Elixhauser Comorbidity Index
0	95878 (94.1)	5995 (5.9)	<0.001
1–2	205673 (92.8)	15999 (7.2)
3–5	143080 (92.5)	11680 (7.6)
≥ 6	41607 (90.2)	4539 (9.8)

Values are N (%) showing row percentages, or median (IQR). Abbreviations: lbs, pounds; IQR, interquartile range; y, year; CVA: cerebrovascular accident; TIA: transient ischemic attack; COPD: chronic obstructive pulmonary disease.

Age on March 19, 2020.

Self-reported race/ethnicity from the electronic health record.

Multivariable logistic regression demonstrated that compared to adults ages 65–79 years, young adults ages 18–39 years had the highest risk of gaining ≥ 15 pounds (adjusted OR 5.19, 95% CI 5.01–5.38) ( Table 2). Residing in a low-income neighborhood was independently associated with weight gain (adjusted OR 1.23, 95% CI 1.19–1.28). Black race was associated with weight gain in an unadjusted analysis (OR 1.25, 95% CI 1.21–1.30). However, this association was significantly attenuated after adjusting for other risk factors including neighborhood income levels (adjusted OR 1.06, 95% CI 1.02–1.10). Having a diagnosis of depression pre-pandemic was also associated with weight gain during the pandemic (adjusted OR 1.54, 95% CI 1.50–1.58).

Table 2

Association between baseline characteristics and ≥ 15 lb weight gain.

	Univariable Association with ≥ 15 lbs weight gain OR (95% CI)	Multivariable Association with ≥ 15 lbs weight gain OR (95% CI)
Agea, y
18–39	3.93 (3.81–4.06)	5.19 (5.01–5.38)
40–64	1.67 (1.63–1.71)	2.00 (1.94–2.05)
65–79	Reference	Reference
≥ 80	0.65 (0.61–0.69)	0.55 (0.52–0.59)
Sex
Female	Reference	Reference
Male	0.97 (0.95–0.99)	1.02 (1.00–1.05)
Race/ethnicity
White	Reference	Reference
Black	1.25 (1.21–1.30)	1.06 (1.02–1.10)
Asian	0.37 (0.36–0.39)	0.34 (0.33–0.36)
Hispanic	0.99 (0.97–1.02)	0.77 (0.7–0.79)
Other	0.90 (0.85–0.96)	0.70 (0.66–0.74)
Income, $
More than 80000	Reference	Reference
45001–80000	1.26 (1.24–1.29)	1.14 (1.12–1.17)
Less than 45000	1.41 (1.36–1.47)	1.23 (1.19–1.28)
Comorbidities
Hypertension	0.84 (0.82–0.85)	1.21 (1.18–1.24)
Diabetes	0.85 (0.83–0.87)	0.99 (0.96–1.02)
CAD	0.92 (0.88–0.95)	1.03 (0.98–1.07)
Heart failure	1.42 (1.35–1.49)	1.57 (0.48–1.66)
Atrial fibrillation	1.06 (1.01–1.12)	1.27 (1.20–1.35)
CVA/TIA	1.07 (1.01–1.13)	1.26 (1.48–1.66)
COPD / Asthma	1.28 (1.25–1.32)	1.24 (1.21–1.27)
Depression	1.71 (1.67–1.74)	1.54 (1.50–1.58)

Abbreviations: OR, odds ratio; CI, confidence interval; lbs, pounds; y, year; CAD: coronary artery disease; CVA: cerebrovascular accident; TIA: transient ischemic attack; COPD: chronic obstructive pulmonary disease.

Age on March 19, 2020.

Discussion

In this racially and ethnically diverse population in southern California, significant weight gain of 15 pounds or more was observed in 7.3% of the adult population during the COVID-19 pandemic. Young adults, individuals who resided in low-income neighborhoods, and patients with depression were disproportionally affected.

These findings have policy implications, as identifying groups at high risk of weight gain allows targeted interventions for obesity prevention. Compared to older adults in the 65–79 years age group, individuals in the 18–39 years age group were 5.2 times more likely to gain more than 15 pounds during the pandemic. Weight gain during early to middle adulthood has been shown to be associated with significantly increased risk of major chronic diseases including cardiovascular disease and obesity-related cancer [8]. Intervention strategies to increase physical activity, reduce sedentary behavior, and provide affordable food options may be particularly important for young adults and those living in disadvantaged neighborhoods.

Limitations of this study include the observational design and inclusion of only those with weight measurements. Findings from this well-insured population may not be generalizable to those without insurance.

Ethical statement

This study was approved by the Institutional Review Board of KPSC with a waiver of informed consent. The authors have read and have abided by the statement of ethical standards for manuscripts submitted to Obesity Research & Clinical Practice.

Funding

None.