TABLE 2.

Characteristics and findings summary of studies that sampled a clinical cohort

Study	Design	Country	Date	Sample	Brief summary of relevant findings	Additional comments
(Akgül et al., 2021)	Cross	Turk	May–Jun‐20	38 adolescents (95% girls); AN‐restrict (68%); AN‐binge‐purge (13%); atypical AN (8%); BN (8%); OSFED (2%); race/ethnicity N/R	21% reported that their ED overall was worse because of lockdown. 53% reported that lockdown affected their access to mental healthcare. 37% spent more time trying to control their weight/shape during lockdown. 37% reported that their general and ED‐specific quality of life had been negatively affected by lockdown.	Unclear how ED was confirmed. Items were self‐created. Regressions were conducted to explore correlates of symptom deterioration, but variables modeled were not clear.
(Baenas et al., 2020)	Long (retro))	Spain	Prelockdown unclear During lockdown Apr‐20	74 adult treatment‐seeking patients confirmed via interview (96% women); n = 19 AN; n = 12 BN; n = 10 BED; n = 33 OSFED. race/ethnicity N/R	19 patients self‐reported symptom deterioration while 55 self‐reported no change in symptoms during the lockdown. Depressive & anxiety symptoms were associated with symptom deterioration during lockdown. 41% and 29% of participants reported significant symptoms with anxiety and depression, respectively.	Data were collected via telephone interview. Description of missing data was missing. Symptom deterioration items were self‐created.
(Branley‐Bell & Talbot, 2020)	Cross	UK	Apr‐20	129 community‐based adolescents/adults with current ED or recovering from ED based on self‐report (94% females). Race/ethnicity N/R	87% reported that their symptoms had worsened, with 30% reporting that their symptoms were “much worse” because of the pandemic.	Recruitment targeted towards social media advertisements and snowballing methods. Description of missing data was lacking.
(Brothwood, Baudinet, Stewart, & Simic, 2021)	Cross	UK	Mar–Nov‐20	14 adolescents with AN and 19 parents participating in an intensive treatment program (93% female). Race/ethnicity N/R	16% of young people perceived online family therapy sessions to be more helpful than face‐to‐face family therapy sessions. 8% of young people perceived online individual therapy sessions to be more helpful than face‐to‐face individual sessions. Parents generally rated online therapy higher than the young people. Many young people felt that the quality of treatment was impacted by transitioning to online.	Survey response rate was 58% for young people and 37% for parents. Unclear how ED diagnosis was confirmed. Items were self‐created for the purpose of this study.
(Castellini et al., 2020)	Long (retro)	Italy	Pre‐pandemic Jan–Sept‐19 During pandemic Apr–May‐20	74 treatment‐seeking adults with BN/AN confirmed via interview (100% women) 97 healthy controls (100% female); 100% white; other races/ethnicities N/R	A significant increase in binge eating and compensatory behaviors (but not total levels of ED psychopathology) was observed from before to during the lockdown in people with ED. 10 patients who were considered recovered prior to the pandemic had relapsed during the lockdown.	Clinical sample was assessed pretreatment, before lockdown, and during lockdown. Control group was matched on gender and age (but not on living situation or education level) to clinical group and recruited via “local advertisements” Only complete cases were analyzed. Regressions were conducted to explore correlates of symptom deterioration, but the variables modeled were not clear.
(Favreau et al., 2021)	Cross	Germ	Apr–Dec‐20	88 individuals with AN and 30 with BN drawn from a large sample of 538 psychiatric inpatients (70% women). Race/ethnicity N/R	35% and 23% of patients with AN and BN strongly agreed that their symptoms had worsened during the pandemic, respectively. Ratings of perceived burden of contact restrictions were higher for AN and BN relative to individuals with anxiety disorder. Daily structuring as a coping strategy was perceived to be more helpful by people with AN relative to people with depression and OCD.	Completion rate for the online survey was 64%; unclear how partial completers were handled. All participants received inpatient treatment at six hospitals in Germany during COVID‐19. Unclear how diagnoses were established. Items were self‐created.
(Fernandez‐Aranda et al., 2020)	Cross	Spain	Jun–Jul‐20	127 adults, including 87 in‐patients with an eating disorder (n = 55 AN, n = 18 BN, n = 14 OSFED) and 34 patients with obesity, confirmed by interviews (86% women). Race/ethnicity N/R	For people with AN (but not for BN and OSFED), significant reductions after COVID‐19 confinement were observed for factors “impact on eating symptoms,” “changes in eating style,” and “changes in emotion regulation” from the COVID isolation eating scale. There were no significant differences in telemedicine acceptability ratings between AN, BN, and OSFED.	Recruitment occurred at six different child/adolescent units in Spain, which are representative of the public and private health sectors in Barcelona. The self‐created COVID isolation eating scale asks participants to rate their symptoms twice, once before confinement and one after confinement. Retrospective recall likely a significant bias in this study. Unclear whether missing data were present or how it was handled.
(Giel, Schurr, Zipfel, Junne, & Schag, 2021)	Long (retro)	Germ	Pre‐pandemic May–Jun‐17 During pandemic May–Jul‐20	42 adults with BED who previously participated in an RCT, confirmed via interview (80% women). Race/ethnicity N/R	Confirmed BED cases were lower after the lockdown period compared to prelockdown period (50% vs. 100%). A significant increase in binge eating was observed for the 4 weeks during lockdown as compared to immediately before COVID‐19 outbreak. Self‐reported ED psychopathology (EDE‐Q global) at the lockdown follow‐up was higher as compared to both previous assessments (when entering the trial and prelockdown). Fewer individuals fulfilled a comorbid mental health diagnosis after COVID‐19 lockdown (8%) as compared to pre‐pandemic time‐points (23%).	52% retention rate for the follow‐up period after COVID‐19 lockdowns. Description of missing data was lacking.
(Graell et al., 2020)	Long (retro)	Spain	Mar–May‐20	Medical records of children and adolescents with ED seeking treatment before (n = 22) and during the confinement period (n = 22; 100% female). Race/ethnicity N/R	During confinement period, 1818 outpatient contacts were carried out (73% by phone and 27% face‐to‐face). 22 patients were newly admitted and 68 emergencies were treated. 42% of patients reported a reactivation of symptoms due to COVID‐19. 68.2% of patients and their families identified the onset of confinement as a possible precipitating factor for admission. On admission 45.5% of patients presented irritability and 22.7% presented mood disturbances due to confinement. Higher rates of comorbidities, affective disorders and suicide risk were observed in the pandemic compared to pre‐pandemic periods (number of admissions and source of referrals did not differ between the two periods).	Records presented from outpatient, day hospital and inpatient program of the Child & Adolescent Eating Disorders Unit of the hospital Infantil Universitario Niño Jesús in Madrid during the 8 weeks of confinement.
(Hansen et al., 2021)	Long (retro)	NZ	Pre‐pandemic Jan–Dec‐19 During pandemic 2020 period	236 electronic records of child, adolescent, and adult inpatient and outpatient admissions pre‐pandemic postpandemic (95% female); 94% European; 6% Māori; 2% other	2020 monthly admission numbers were higher than in the corresponding month in 2019, with a noticeable rise in march–April (first lockdown). Overall impatient admissions doubled in 2020 compared to 2019 for adults but not for children. Adults and children doubled in the proportion of first‐ever admissions during pandemic period (mainly in the second half of 2020). Child and adolescent outpatient services saw an average 60% increase in referrals per month following lockdown.	Clinical records were gathered from referrals for eating disorders in the Waikato District health board catchment.
(Leenaerts, Vaessen, Ceccarini, & Vrieze, 2021)	Long (pros)	Belg	Unclear	15 adults with BN confirmed via interview (100% women); 87% European 13% Asian	During lockdown, patients reported higher levels of negative affect and lower levels of positive affect. Patients who experienced a higher binge eating frequency during the lockdown also experienced a stronger change in negative and positive affect. Time spent at home, and time spent with family, housemates, partner were unrelated to binge eating during lockdown periods.	Subset of participants extracted from larger study; unclear why this sub‐sample was used. Eight signals over nine days were sent to participants to respond to EMA items. Very small sample size.
(Levinson, Spoor, Keshishian, & Pruitt, 2021)	Long (pros)	US	Pre‐pandemic Mar‐2018/2020 During pandemic Mar‐2020–Jan‐2021	93 treatment‐seeking adults confirmed via interview (86% women) who received either in‐person or telemedicine treatment (43% AN; 10% BN; 34% OSFED; 9% BED; 2% ARFID); 95% white; 2% black; 1% Asian; 1% mixed race	Both groups (telemedicine & face‐to‐face) reported significant improvements in ED psychopathology (EDE‐Q global), depressive symptoms and perfectionism scores, with no between‐group differences noted.	The two cohorts did not differ on clinical variables except parental criticisms; unclear whether the two cohorts were matched on demographic variables. The two treatment groups were identical in content. Missing data/attrition not mentioned.
(Lewis, Elran‐Barak, Grundman‐Shem Tov, & Zubery, 2021)	Cross	Israel	Apr–May‐20	63 treatment‐seeking individuals (90% women); 38% AN; 32% BN; 25% BED. race/ethnicity N/R	~40% agreed that the transition to online treatment adversely affected the quality of care and the effectiveness of treatment. 9% would prefer to continue to use online treatment than face‐to‐face treatment. The only correlate of positive perceptions of online treatment transition was a longer duration of illness.	Diagnoses determined via clinical discussions. 80% survey completion rate description of missing data was lacking) Items were self‐created.
(Lin et al., 2021)	Long (retro)	US	Pre‐pandemic Jan‐2018–Mar‐2020 During pandemic Apr‐2020–Feb‐2021	Service utilization data were analyzed (no participant information provided)	At the onset of the pandemic, there was no immediate shift in number of inpatient medical admissions and inpatient bed‐days; however, at post‐pandemic periods, number of admissions per month increased over time. Completed new outpatient assessments began increasing over time as the pandemic continued. Pre‐pandemic patient inquiries were stable over time, while post‐pandemic inquiries increased.	ED program is within a tertiary care children's hospital in Boston caring for patients approximately 8–26 years old with any ED diagnosis.
(Machado et al., 2020)	Long (retro)	Port	Pre‐pandemic unclear During pandemic Apr–May‐20	43 adults (95% women) patients (46% AN; 32% BN; 5% BED; 16% OSFED). Race/ethnicity N/R	Level of ED psychopathology (EDE‐Q global), impairment and emotion dysregulation did not change over time (pre to during pandemic). Coronavirus impact scale scores were significantly associated with each criterion variable 58% reported moderate/severe stress related to the pandemic, 16% reported family conflict related to the pandemic, 37% reported abrupt changes to mental health care access.	Participants recruited from an ongoing naturalistic study (45% agreed to participate). Assessments were conducted via telephone. Not clear how ED diagnosis was confirmed or when the first assessment was conducted.
(Mansfield et al., 2021)	Long (retro)	UK	Pre‐pandemic Jan‐2017/2019 During pandemic Aug‐20	> 10 million electronic records of adult health care contacts (50% women); 49% white; 5% south Asian; 3% black; 2% other; 1% mixed	There was a reduction in general practitioner contact behavior for EDs when comparing pre and during pandemic time periods.	Records were based on anyone over age 11 years.
(Monteleone et al., 2021)	Cross	Italy	Jun‐20	312 adults with ED confirmed via interview (96% women); 57% AN; 27% BN; 15% BED; 7% OSFED. race/ethnicity N/R	Ineffectiveness, impulsivity, and self‐induced vomiting were higher both during and after lockdown relative to pre‐COVID‐19 periods. Social security, body dissatisfaction and binge eating scores were higher during lockdown compared to after lockdown periods.	Participants answered survey items in relation to three time‐periods (prior, during, and after lockdowns). Description of missing data was lacking. Items were adapted from previously established surveys.
(Pensgaard, Oevreboe, & Ivarsson, 2021)	Long (pros)	Italy	T1 Mar‐Apr‐2020 T2 Jun‐2020	40 treatment‐seeking patients confirmed by interview (98% women); n = 22 AN; n = 22 BED; n = 15 BN. Race/ethnicity N/R	Restrictive eating and depression, anxiety and stress scores did not change from pre to during lockdown periods among the clinical sample, but loss of control eating, body image concerns, and psychological wellbeing scores improved	Dropouts differed to completers only on a measure of food preoccupation.
(Plumley, Kristensen, & Jenkins, 2021)	Long (pros)	UK	Unclear	9 patients with AN undergoing day‐patient treatment virtually (89% women); 77% white; other races/ethnicities N/R	Patients transitioning to a day‐patient program online (i.e., videoconferencing) experienced large improvements in core ED symptoms, and depression and anxiety symptoms.	Conclusions are difficult due to the very small sample size.
(Raykos, Erceg‐Hurn, Hill, Campbell, & McEvoy, 2021)	Long (pros)	Aus	Mar–Apr‐20	25 treatment‐seeking patients (93% women) confirmed via interview; 48% AN; 20% BN; 28% OSFED; 4% UFED. 70% Anglo‐European‐Australian; other races/ethnicities N/R.	Participants who were forced to transition to telehealth experienced large reductions in ED psychopathology, impairment, and mood states. The level of change from telehealth was almost identical to historical benchmarks at the same clinic (face‐to‐face treatment). 71% perceived telehealth to be as good as or better than face‐to‐face treatment. The quality of the therapeutic relationship during telehealth sessions was rated as being “as good as usual” (88%).	Unclear whether historical benchmarks were matched on key demographics, although they did not differ on symptom severity. Different treatment approaches were delivered based on the age and diagnosis of the patient.
(Richardson, Patton, Phillips, & Paslakis, 2020)	Long (retro)	Can	Pre‐pandemic Mar–Apr‐2018/2019 During pandemic Mar–Apr‐20	All individuals (87% female) who contacted NEDIC through the helpline or instant chat function (demographic info N/R).	NEDIC was contacted 609 times (120 calls, 418 instant chats, 71 emails) during the pandemic period; most were for support (64%) or referral (20%), and 78% of help‐seekers were women. Number of NEDIC contacts was higher during the pandemic period than during a 2018 (but not 2019) period. Most affect people using NEDIC services were women (86%), and the most prevalent diagnoses were AN (31%) and BED (41%). Self‐reported symptoms of dieting, over‐exercising, perfectionism, purging, depression and anxiety were higher in the pandemic period compared to pre‐pandemic periods (no differences in binge eating and weight preoccupation). 73% of people who contacted NEDIC because of COVID‐19 reported that their symptoms had gotten worse during isolation.	NEDIC is a national non‐profit organization (Canada) that uses free helpline and instant chat services to assist those affected by ED.
(Schlegl, Maier, et al., 2020)	Cross	Germ	May‐20	159 former inpatients with AN (100% women). Race/ethnicity N/R	41% agreed/strongly agreed that their symptoms were worse during the pandemic; 20% agreed/strongly agreed that they developed new symptoms; 51% agreed/strongly agreed that their quality of life had worsened; 27% agreed/strongly agreed that their therapy was impaired. The percentage stating that the following symptoms had worsened “much more” during the pandemic was: Drive for thinness (28%), fear of weight gain (36%), body dissatisfaction (35%), eating concerns (42%), shape and weight concerns (~30%), restrictive eating (14%), binge eating (4%), self‐induced vomiting (6%), laxative and diuretic abuse (2%). Feelings of sadness (30%), loss of pleasure (30%), interest (22%) and energy (28%), loneliness (41%), and symptoms of anxiety (>10%) had worsened during the pandemic. 28% of the total sample agreed/strongly agreed that the pandemic had impacted their treatment experience.	Participation rate was 59% overall. Items were self‐created. Description of missing data was lacking.
(Schlegl, Meule, et al., 2020)	Cross	Germ	May‐20	55 former inpatients with BN confirmed via interview (100% female) Race/ethnicity = N/A	49% reported that their ED had worsened during the pandemic; 61% reported that their quality of life had been negatively affected; 45% reported significant disruptions to their treatment; 40% reported that they had developed new symptoms; >75% reported more pronounced symptoms of depression and general psychopathology. >80% reported increases in eating, shape and weight concerns, fear of weight gain, and drive for thinness. Binge eating increased in 47% of patients, self‐induced vomiting in 36%, and laxative and diuretic abuse increased in 9% and 7% of patients, respectively. Use of videoconference‐based therapy increased from 3.6% to 21.8% and use of telephone contacts from 18.2% to 38.2%, whereas the use of additional online interventions decreased from 3.6% to 0%. 45% of the total sample agreed/strongly agreed that the pandemic had impacted their treatment experience.	25% survey completion rate among all participants invited. Survey was self‐created. Description of missing data was lacking.
(Shaw et al., 2021)	Long (retro)	UK	Pre‐pandemic Mar–Jul‐19 During pandemic Mar–Jul‐20	Service evaluation conducted at the eating disorder young person service (UK), including 12 adolescent patients with an ED, 19 parents/carers, and 12 staff members. Gender /race/ethnicity N/R	Number of urgent referrals increased to 35% from March–July (2020) compared to 21% in the same period in 2019. The number of appointments offered increased during the lockdown period (M = 402.4, SD = 37.9) compared to the previous months prior (M = 265, SD = 37.2). 92% of service staff disagreed that young patients were coping with COVID‐19, while 26% of carers and 16% of patients disagreed that they were coping better. Patient satisfaction ratings slightly increased during COVID‐19, but carers and staff ratings slightly decreased.	Authors created their own items for purpose of the study.
(Spettigue et al., 2021)	Long (retro)	Can	Pre‐pandemic Apr–Oct‐19 During pandemic Apr–Oct‐20	91 adolescents (43 pre‐pandemic and 48 during pandemic) with an ED (83% female); ~85% AN. Race/ethnicity N/R	39% reported that their ED was triggered by the pandemic. Those who had their ED triggered had a lower BMI, were more medically unstable, and were more likely to be admitted four weeks after assessment than a 2019 cohort and those who were not triggered by COVID‐19. The cohort exposed to the pandemic reported higher dietary restraint and impairment scores than a separate pre‐pandemic cohort; no differences on other symptom measures were observed.	The two cohorts differed on BMI but not on gender distribution or age. Extent and handling of missing data were not clear.
(Spigel et al., 2021)	Cross	US	Jul‐20	73 treatment‐seeking young people with self‐reported ED (93% female); white = 79%; Asian = 7%; Hispanic = 6%; black = 1% mixed race = 6%; other = 1%.	32% reported a disruption to treatment as a result of the pandemic. 67% with telehealth access found care to be better or as good as usual. 81% endorsed increased intrusive eating disorder thoughts and behaviors due to the pandemic. Those who perceived treatment disruption and still had access to care had a higher odds of intrusive ED thoughts.	Authors created their own items for purpose of the study.
(Stewart et al., 2021)	Cross	UK	May–Jul‐20	53 adolescents with an ED (AN/OSFED), 75 parents, and 23 clinicians. Gender /race/ethnicity N/R	Clinicians perceived the levels of engagement from their patient were not changed by the transition to online treatment. Young people and parent's indicated that their overall experience of online therapy was positive and that they felt understood, with a low level of impact of technology on their treatment experience. Both parents and young people indicated little impact on the therapeutic relationship when transitioning to online treatment. Parents were more likely to opt for online treatment preferences compared to the patients when restrictions ease (17% vs. 6%).	All clinicians, patients and parents from Maudsley Centre for Child and Adolescent Eating Disorders were invited. Survey completion rate was 33% for young patients, 47% for parents, and 66% clinicians. Description of missing data was lacking. All responses were based on retrospective recall Items were self‐created for the purpose of this study
(Taquet, Geddes, Luciano, & Harrison, 2021)	Long (retro)	US	Pre‐pandemic 2017–2020 During pandemic 2020–2021	> 5 million electronic health records of adolescent patients (55% female; 8,471 diagnoses with an ED during the pandemic period).	During the pandemic, an increase of ED diagnoses of 15% was observed compared with the prior year, with significant excesses observed in each 2‐month period during the pandemic period except for March–May 2020. Increased risk was observed for females, those aged 10–19 years, and mostly affected AN diagnoses. Compared to those diagnosed with an ED in the past 3 years, those diagnosed during the pandemic were at higher risk of attempting suicide and having suicidal ideation (no differences in death rates).	Records were drawn from a federated EHR network with anonymized data from 81 million patients (93% from the US) seeking hospital, primary care and specialist provider services
(Termorshuizen et al., 2020)	Cross	US	Apr‐20	511 adults from the US (97% women) and 510 adults from Netherlands (99% women) who self‐reported a current or lifetime ED. race/ethnicity N/R	Between 3–53% of the total sample reported being “very concerned” about the impact of COVID‐19 on their ED depending on the specific item asked. Most common reasons for concern levels were “lack of structure,” “triggering environment,” and “lack of social support.” Percentage of participants who reported engaging in specific ED behaviors daily due to the pandemic was: 5–6% for binge eating, 14–19% for restriction, 15% for compensatory behaviors, and 28% for exercise anxiety. >50% of the total sample reported that they were worried that COVID‐19 was going to impact their mental health. 47% of patients in the US and 74% in Netherlands rated their treatment in the last 2 weeks as “somewhat” or “much worse” than usual	Recruitment was aimed at social media or via emails to participants from other studies. Items were self‐created. Description of missing data was lacking.
(Vitagliano et al., 2021)	Cross	US	Jun–Aug‐20	89 younger individuals with a self‐reported ED (89% women); 78% white; other races/ethnicities N/R	73% reported an increase in depressive symptoms due to COVID‐19, 77% reported an increase in anxiety, 80% reported an increase in isolation and 74% reported an increase in intrusive eating disorder thoughts. 29% reported a decrease in motivation to recover due to the pandemic. Living in a triggering environment was correlated with intrusive ED thoughts, reported increases in depression/anxiety, and lower motivation to recover.	Items were self‐created for the purpose of this study, but adapted from previously published work. Participants were a sub‐sample from a larger study (56% response rate). Completers did not differ to dropouts on age at enrolment, race/ethnicity, or sex, but did differ in restrictive ED rates.
(Vuillier, May, Greville‐Harris, Surman, & Moseley, 2021)	Cross	UK	Unclear	207 adults with a self‐reported ED (64% women); 94% white; 5% Asian; 0.5% black; 0.5% Asian	83% reported that their ED symptoms had worsened as a result of the pandemic, with no differences between ED subtypes. Changes to routine, changes to physical activity, and difficulties with emotion regulation were cited as the three most influential exacerbating factors.	Participants recruited through prolific website and social media. Items were self‐created. Description of missing data was unclear.
(Yaffa et al., 2021)	Long (retro)	Israel	Pre‐pandemic 2015–2019 During pandemic Jan–Oct‐20	Service data at a pediatric ED treatment Centre in Israel. sample demographics N/R	Compared to means reported for the period of 2015–2019, means reported for 2020 were higher for number of treatment sessions offered (5,926 vs. 4,001), and meetings with a psychiatrist (662 vs. 433), clinical nutritionist (1,722 vs. 750), and mental health professional (3,318 vs. 1,690). The mean number of existing (242 vs. 257) and new patients (127 vs. 166) between the two periods were highly similar.	The ED treatment Centre offers inpatient, day care, and ambulatory services for children and adolescents with EDs.

Abbreviations: AN, anorexia nervosa; Aus, Australia; BED, binge‐eating disorder; BN, bulimia nervosa; Braz, Brazil; Can, Canada; Cross, cross‐sectional; Fran, France; Germ, Germany; Leb, Lebanon; long (pros), longitudinal prospective design; long (retro), longitudinal retrospective design; N/R, not reported or unclear; NZ, New Zealand; OSFED, other specified feeding or eating disorder; Port, Portugal; UK, United Kingdom; US, United States.