Effects of a Social Media Intervention on Vaping Intentions: Randomized Dose-Response Experiment.

BACKGROUND: e-Cigarette use, especially by young adults, is at unacceptably high levels and represents a public health risk factor. Digital media are increasingly being used to deliver antivaping campaigns, but little is known about their effectiveness or the dose-response effects of content delivery. OBJECTIVE: The objectives of this study were to evaluate (1) the effectiveness of a 60-day antivaping social media intervention in changing vaping use intentions and beliefs related to the stimulus content and (2) the dose-response effects of varying levels of exposure to the intervention on vaping outcomes, including anti-industry beliefs, vaping intentions, and other attitudes and beliefs related to vaping. METHODS: Participants were adults aged 18 to 24 years in the United States. They were recruited into the study through Facebook (Meta Platforms) and Instagram (Meta Platforms), completed a baseline survey, and then randomized to 1 of the 5 conditions: 0 (control), 4, 8, 16, and 32 exposures over a 15-day period between each survey wave. Follow-up data were collected 30 and 60 days after randomization. We conducted stratified analyses of the full sample and in subsamples defined by the baseline vaping status (never, former, and current). Stimulus was delivered through Facebook and Instagram in four 15-second social media videos focused on anti-industry beliefs about vaping. The main outcome measures reported in this study were self-reported exposure to social media intervention content, attitudes and beliefs about vaping, and vaping intentions. We estimated a series of multivariate linear regressions in Stata 17 (StataCorp). To capture the dose-response effect, we assigned each study arm a numerical value corresponding to the number of advertisements (exposures) delivered to participants in each arm and used this number as our focal independent variable. In each model, the predictor was the treatment arm to which each participant was assigned. RESULTS: The baseline sample consisted of 1491 participants, and the final analysis sample consisted of 57.28% (854/1491) of the participants retained at the 60-day follow-up. We compared the retained participants with those lost to follow-up and found no statistically significant differences across demographic variables. We found a significant effect of the social media treatment on vaping intentions (ß=-0.138, 95% CI -0.266 to -0.010; P=.04) and anti-industry beliefs (ß=-0.122, 95% CI 0.008-0.237; P=.04) targeted by the intervention content among current vapers but not among the full sample or other strata. We found no significant effects of self-reported exposure to the stimulus. CONCLUSIONS: Social media interventions are a promising approach to preventing vaping among young adults. More research is needed on how to optimize the dosage of such interventions and the extent to which long-term exposure may affect vaping use over time. TRIAL REGISTRATION: ClinicalTrials.gov NCT04867668; https://clinicaltrials.gov/study/NCT04867668.

Pathways to prevent e-cigarette use: Examining the effectiveness of the truth antivaping campaign.

OBJECTIVE: Mass media campaigns have been designed to counter a rise in e-cigarette use among young people. No studies to date have established pathways from campaign exposure to e-cigarette use behaviors. This study examines the mechanisms through which exposure to the truth® campaign may prevent the progression of e-cigarette use among youth and young adults. METHOD: Data included four waves of the truth longitudinal cohort, a probability-based, nationally representative survey: Wave 1: September 2020-March 2021; Wave 2: July-October 2021; Wave 3: January-May 2022; and Wave 4: October 2022-January 2023. The sample (N = 4,744) was aged 15-24 years and nicotine naive at Wave 1. Latent growth structural equation modeling techniques examined the pathway from cumulative frequency of ad exposure (CFE) to the e-cigarette use progression via campaign-targeted attitudes. RESULTS: The direct effect from CFE to e-cigarette use progression was not significant. The overall indirect pathway shows that CFE was significantly associated with lower progression of e-cigarette use (ß = -.01, p < .0001). CFE had a significant positive association with each campaign-targeted attitude, and each attitude was significantly associated with stronger perceived norms against e-cigarette use. Stronger perceived norms were significantly associated with a slower progression to e-cigarette use (ß = -.21, p < .0001). CONCLUSIONS: Awareness of the truth antivaping campaign follows a pathway of targeted attitudes and perceptions of acceptability, then to slowed progression toward initiation of e-cigarette use. Antivaping campaigns should focus on shifting perceptions of acceptability to reduce e-cigarette use among young people. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Treatment-seeking young people enrolled in a United States vaping cessation intervention trial report high frequency of use and nicotine dependence.

Objective: This study examines characteristics of participants enrolled in a vaping cessation intervention trial and study generalizability of the treatment-seeking sample to the broader population of young people interested in quitting vaping to evaluate dissemination of an evidence-based treatment program. Methods: Data was obtained from 697 treatment-seeking participants (aged 13-24 years) from a vaping cessation intervention trial conducted between February and March 2023 with This is Quitting and 665 participants who expressed intent to quit vaping in the Truth Longitudinal Cohort, a nationally representative longitudinal study of United States youth and young adults (aged 15-24 years), collected October 2022 to February 2023. Comparisons were made using two-sample Pearson Chi-square tests and t-tests. Results: Treatment-seeking young people were younger, less racially diverse, more diverse in sexual orientation, and reported higher psychological distress, frequency of e-cigarette use, and nicotine dependence, relative to the nationally representative sample of young people expressing intentions to quit vaping. Conclusions: Participants enrolled in treatment reported higher levels of dependence and use frequency than the broader population, suggesting that many young e-cigarette users with lower dependence who want to quit might not be reached by current treatment dissemination efforts. The implication of these findings is that communications for vaping cessation programs may need to be adjusted to have broader appeal among young people.

Patterns of Daily Cigarette and E-cigarette Use among United States Youth and Young Adults: Insights from the Truth Longitudinal Cohort between 2018 and 2019.

Purpose: Temporal patterns of daily tobacco product use among ever users from the Truth Longitudinal Cohort (TLC) between 2018 and 2019 were explored. Methods: The sample (N = 5274) includes individuals (15-36 years), residing in the United States, who had ever used any tobacco product at Wave 7 (February - May 2018) and provided tobacco use information at Wave 9 (September - December 2019). Results: There was a nonsignificant 1.1 percentage point increase in daily tobacco use (on at least 25 of the past 30 days), from 14.6% (95% CI: 12.8, 16.6) to 15.7% (95% CI: 13.8, 17.7). Tobacco product use remained stable over time, as 65.3% (95% CI: 56.4, 73.3) of daily cigarette smokers, 57.0% (95% CI: 43.6, 69.4) of daily e-cigarette vapers, and 8.5% (95% CI: 2.0, 29.3) of daily dual users stayed with their primary tobacco product. There was also some evidence of switching, as 7.5% (95% CI: 3.7, 14.8) of daily cigarette smokers became daily e-cigarette vapers and 2.3% (95% CI: 0.7, 6.8) of daily e-cigarette vapers became daily cigarette smokers. Discussion: Although most daily tobacco users were likely to continue using their primary product, some daily users transitioned to daily use of other products - suggesting that policies and public education focused on reducing overall nicotine use are essential for addressing the nicotine epidemic among young people.

Reducing e-cigarette use among youth and young adults: evidence of the truth campaign's impact.

BACKGROUND: Mass media campaigns have been shown to be effective in reducing cigarette use. However, evidence is limited for whether campaigns can shift e-cigarette use among youth and young adults (YYA). To assess the impact of the truth anti-e-cigarette campaign, which focused on the effects of vaping on mental health, this study examines the relationship between campaign awareness and e-cigarette behaviour among YYA. METHODS: Data from weekly cross-sectional surveys of YYA aged 15-24 years from September 2021 to October 2022 were used for multilevel models assessing how weekly campaign awareness is related to intentions to use e-cigarettes and current e-cigarette use (past 30 days). Weekly campaign awareness was calculated by averaging individual-level awareness for each week. Control variables included individual-level campaign awareness, sociodemographics, perceived financial situation, parental smoking, sensation seeking, and mental health. RESULTS: Weekly campaign awareness ranged from 50% to 78%, with most weeks (77%) being within 65% and 75% of weekly campaign awareness. At weekly awareness levels between 65% and 75%, there was a significant association with lower intentions to use e-cigarettes. A dose-response relationship was observed for current use: compared with weeks with lower (<65%) awareness, weeks with awareness of 65-70% had 14% lower odds of current use, weeks with 70-75% awareness had 16% lower odds and weeks with >75% weekly awareness had 18% lower odds (p=0.018, p=0.009 and p=0.007, respectively). CONCLUSIONS: Findings from this analysis of weekly campaign awareness demonstrate that exposure to the truth anti-e-cigarette campaign is associated with significantly lower odds of intentions to use and current use of e-cigarette among YYA.

Vaping-Know the Truth: Evaluation of an Online Vaping Prevention Curriculum.

BACKGROUND: Unacceptably high levels of e-cigarette use among youth paired with growing research about the dangers of vaping demonstrate a critical need to develop interventions that educate young people to reject e-cigarette use and promote cessation for current users. Vaping: Know the Truth (VKT) is a free digital learning experience prioritizing middle and high school students that aims to improve students' knowledge about the dangers of using e-cigarettes and provide quitting resources for those who already vape. The current study was designed to evaluate whether students receiving the curriculum increased knowledge of the dangers of vaping. METHODS: The outcome measures were calculated as the change in the number of correct responses from the pre- to post-module assessments among middle and high school students who completed four modules of the VKT curriculum (N = 103,522). Linear regression was performed to determine the association between the student's pre-module assessment score and the knowledge change score after completion of the four modules. RESULTS: Students' e-cigarette knowledge significantly improved by an average of 3.24 points (SD: 3.54), following implementation of the VKT curriculum. This indicates that participants answered more than 3 additional questions correctly, on average, after the intervention. CONCLUSION: Findings demonstrate that the Vaping: Know the Truth curriculum is an effective resource for increasing knowledge among youth about the harms associated with e-cigarette use. Further research is needed to evaluate whether the intervention is associated with behavioral outcomes over time.

Transitions in Frequent to Daily Tobacco and Nicotine Use among Youth and Young Adults.

Objective: To examine use and frequency patterns across e-cigarettes, cigarettes, and little cigars, cigarillos, and cigars (LCCs) over time. Methods: Data were obtained from the Truth Longitudinal Cohort (TLC), a nationally representative longitudinal cohort of youth and young adults. Latent class analysis was conducted to classify participants (n = 5274) into subgroups based upon frequency of use of cigarettes, e-cigarettes, and little cigars, cigarillos, and cigars (LCCs) in the past 30 days. Latent transition analysis was used to estimate the probability of use pattern transitions across 23 months (February 2018 to December 2019), adjusted for the effects of gender, race/ethnicity, financial situation, sensation seeking, parent education, and household smoking. Findings: Findings reveal four groups of tobacco product users: (1) frequent to daily cigarette users (9%), (2) frequent to daily cigarette and LCC users (3%), (3) frequent to daily e-cigarette users (10%), and (4) former or noncurrent tobacco users (78%). Although most respondents (69-94%) retained their initial user patterns during the observation period, results also indicate shifts between user groups. Notably, 14% of frequent to daily cigarette and LCC users transitioned to frequent to daily cigarette use, while 6% of frequent to daily cigarette and LCC users, 9% of frequent to daily cigarette users, and 4% of former or noncurrent tobacco users transitioned to frequent to daily e-cigarette use. Conclusion: Although most frequent to daily tobacco users stay with their primary product, there are transitions between frequent to daily cigarette, e-cigarette, and LCC use. Transition patterns may influence risk for nicotine addiction among youth and young adults. Thus, policies focused on preventing and reducing all tobacco use are needed to curb the risk of nicotine addiction among youth and young adults.

Assessing the Feasibility of Studying Awareness of a Digital Health Campaign on Facebook: Pilot Study Comparing Young Adult Subsamples.

BACKGROUND: Mass media campaigns for preventive health messaging have been shown to be effective through years of research. However, few studies have assessed the effectiveness of campaigns on digital media, which is currently how youths and young adults are primarily consuming media. In particular, a platform that can accurately assess exposure to digital messaging in a real-life setting has yet to be developed. OBJECTIVE: This study examines the feasibility of a unique survey platform, Virtual Lab, to conduct a study on exposure to a media campaign within Facebook using a chatbot-style survey administration technique. METHODS: Virtual Lab is a survey platform that was used to recruit and survey participants within Facebook and Facebook Messenger, respectively. We created a Facebook business account with 2 Facebook pages: one for recruitment and disseminating the survey and the other one for serving the target advertisements. Pre- and postexposure surveys were administered via Facebook Messenger using a chatbot-style questionnaire 1 week apart. During this time, the target advertisements were shown to participants who completed the pre-exposure survey. The total time from recruitment to completion of the postexposure survey was 13 days, and incentive costs were US $10 per participant. Survey data were compared between those who completed both pre- and postexposure surveys and those who only completed the pre-exposure survey; that is, those who were lost to follow-up. The demographics of the complete cases were also compared to the US census data. RESULTS: A total of 375 Facebook users aged between 18 and 24 years met eligibility requirements and consented to the study, which consisted of complete cases (n=234) and participants lost to follow-up (n=141). A few differences between complete cases and participants lost to follow-up were observed. Regarding gender, complete cases comprised 40.2% males and 59.4% females, and among participants lost to follow-up, 44.0% were male and 50.4% were female (P=.003). Differences were also observed for e-cigarette use status, where a greater number of current users and fewer past and never users were lost to follow-up than complete cases (P=.01). CONCLUSIONS: The use of Virtual Lab yielded a diverse sample quickly and cost-effectively. Demographic characteristics of participants who completed the study and those who were lost to follow-up were similar, indicating that no biases were caused by the platform during recruitment or testing. This study suggests the feasibility of the Virtual Lab survey platform for studies of media campaign exposure within Facebook. This platform can advance health campaign research by providing more accurate data to inform digital messaging.

Assessing digital advertising exposure using a virtual experimental protocol.

Introduction: The rapid increase in online public education campaigns underscores the need for a better understanding of the effects of exposure to digital advertising and targeted individual-level outcomes. The goal of this study is to develop a virtual experimental protocol to evaluate the dose-response effects of individual-level exposure to digital video ads on campaign outcomes in a naturalistic online browsing context. Methods: Young adults aged 18-24 years (n = 221) completed three 5 min viewing sessions on a realistic mock-up of the YouTube mobile app over a period of 2 weeks, followed by a 10-min survey after the third session. Participants were randomized to view between 0 and 6 exposures of ads from an e-cigarette prevention campaign; respondents viewed a total of 2 ads per session, with 0 to 2 of those ads being non-skippable digital video ads from the campaign and/or a dummy ad. The video ads played prior to short YouTube videos. Outcomes measured were self-reported ad recognition, frequency of ad exposure, and main message knowledge. Results: This study demonstrates a rapidly accessible virtual experimental protocol for evaluating the dose-response effects of digital advertising and individual-level outcomes. Five digital exposures of non-skippable video ads delivered via this platform over a 2-week period generated the highest ad recognition when there were up to six exposures. Higher exposure levels may be needed for message knowledge and ad-content-related effects. Conclusion: This protocol can be extended to investigate dose-response effects and mechanisms of action of individual-level exposure to digital advertising for multiple campaign outcomes, including changes in knowledge, attitudes, and beliefs. Findings can inform evidence for adequate levels of digital exposure in public education campaigns.

Effects of branded health messages on e-cigarette attitudes, intentions, and behaviors: a longitudinal study among youth and young adults.

BACKGROUND: Launched in 2000, the truth campaign was one of the first health-related campaigns to embrace the building of a brand to further amplify its message, such as by building brand equity. Brand equity is an asset that represents the audience's perception of the brand. Previous research supports that strong brand equity is associated with lower tobacco intentions and behaviors; however, brand equity and its change over time have not been studied as it relates to e-cigarettes. This study examines the effects of change in brand equity on e-cigarette attitudes, intentions, and behaviors among youth and young adults. METHODS: The sample (N = 6427) is from the Truth Longitudinal Cohort, a nationally representative, longitudinal cohort of youth and young adults, ages 15-24. Variables include brand equity tobacco scale, demographic characteristics, and e-cigarette use status. The outcomes included anti-e-cigarette attitudes, intentions to use e-cigarettes, and use of e-cigarettes. Multiple and logistic regression models determined the relationship between change in brand equity from respondents at Spring 2018 to Spring 2019 and respondent e-cigarette outcomes at Fall 2019. All models controlled for demographic characteristics and cigarette use. RESULTS: Mean brand equity scores in Spring 2018 were significantly associated with greater anti-e-cigarette attitudes (ß = 0.17, 95% CI: 0.15, 0.19), lower odds of intention to use (OR = 0.75, 95% CI: 0.66, 0.85), and lower odds of current use (OR = 0.81, 95% CI: 0.72, 0.92). Change in brand equity from Spring 2018 to Spring 2019 was significantly associated with greater anti-e-cigarette attitudes (ß = 0.09, 95% CI: 0.06, 0.11) and lower odds of intention to use (OR = 0.79, 95% CI: 0.67, 0.93), but not associated with current use behaviors. CONCLUSIONS: Strengthening brand equity is an effective strategy for influencing anti-e-cigarette related attitudes and intentions, much like it is for anti-smoking campaigns. More research needs to be done on the relationship between change in brand equity and e-cigarette behavior to better understand how brand equity can be wielded to influence change in e-cigarette use behavior.

Effects of Multiple Exposures and Ad-Skipping Behavior on Recall of Health Messages on YouTubeTM.

Although measuring exposure to public health messages is key to understanding campaign effectiveness, little is known about how exposure to and avoidance of digital ad messages may influence self-reported ad recall. A sample of 15-24-year-olds (n = 297) received a varying number of forced-view and skippable test ads across multiple simulated YouTubeTM sessions. Each session was coded for whether the participant viewed the ad or skipped it. While a majority of participants recalled the test ad, the odds of ad recall did not vary by number of sessions (opportunities for exposure). Rather, ad recall was sensitive to the number of completed ad views such that odds of ad recall doubled for each additional time the ad was completely viewed. Findings suggest that public health digital message exposure and recall can be optimized with sufficient attention paid to the proportions of forced-view ads aired when aiming to reach younger audiences.

#toolittletoolate: JUUL-related content on Instagram before and after self-regulatory action.

INTRODUCTION: Digital e-cigarette marketing is largely unregulated and remains easily accessible to young people. The growing public concern around youth JUUL use and its viral presence on social media led the company to engage in several voluntary actions to remove and reduce JUUL-related content on Instagram in May 2018. The current study examined how JUUL-related Instagram content changed in the US following JUUL Labs' wave of voluntary actions in May 2018. METHODS: In 2019, we collected a total of 50,817 JUUL-relevant posts by 16,323 unique users on Instagram from March 1-May 15, 2018 (Phase 1) and May 16-November 11, 2018 (Phase II) using the application programming interface. We conducted a semantic network analysis to identify major topic clusters over time. RESULTS: Approximately 14,838 JUUL-related posts were made by 5,201 accounts in Phase I and 35,979 posts were made by 11,122 accounts in Phase II. Major content clusters remained unchanged over time-key topics were JUUL-related product characteristics and JUUL-communities; the general vape community; and cannabis-related behavior. Of note, cannabis-related content grew in Phase II, particularly use of the term CBD. CONCLUSIONS: Our results reflect the limits of voluntary industry actions to reduce or change vaping-related content on social media. Rather, strong federal restriction on commercial tobacco marketing is the optimal pathway to reduce initial product marketing exposure among youth. These limits would make the emergence and viral contagion of brand-related social media content less likely and reduce its influence on youth behavior.

Validating Self-Reported Ad Recall as a Measure of Exposure to Digital Advertising: An Exploratory Analysis Using Ad Tracking Methodology.

Many mass media campaigns aimed at changing young people's health behavior air on digital platforms rather than on broadcast media (e.g., television), given the intended audience's preference for web-based communication. While research suggests self-reported ad recall correlates with exposure to television advertising, it remains unclear whether self-report measures are correlated with exposure to digital advertising. This study examined the association between an objective measure of digital ad exposure and self-reported recall of digital ads from the truth® tobacco prevention campaign. Digital ad tracking methodology was employed to identify members of an online panel (ages 18-34) who had been exposed to ads during their regular web browsing. Demographics of exposed participants were used to develop a matched control group of non-exposed panel members. Members of the Exposed group (n = 458) and matched Control participants (n = 506) were surveyed on recall of truth ads, media use, and demographics. Results indicated that Exposed participants had significantly higher odds of reporting ad recall compared to Control participants. With each additional ad exposure, the odds of self-reporting higher frequency of ad exposure increased by 8% (OR = 1.08, 95% CI = 1.01-1.16). Findings suggest self-reported measures of ad recall are a valid measure of campaign exposure in a digital media environment.

Bone Parameters in Anorexia Nervosa and Athletic Amenorrhea: Comparison of Two Hypothalamic Amenorrhea States.

Objective: We have reported low bone mineral density (BMD), impaired bone structure, and increased fracture risk in participants with anorexia nervosa (AN) and normal-weight oligoamenorrheic athletes (OAs). However, data directly comparing compartment-specific bone parameters in participants with AN, OAs, and controls are lacking. Design: A total of 468 female participants 14 to 21.9 years old were included: 269 with AN, 104 OAs, and 95 normal-weight eumenorrheic controls. Dual-energy x-ray absorptiometry was used to assess areal BMD (aBMD) of the whole body less head (WBLH), spine, and hip. High-resolution peripheral quantitative computed tomography was used to assess volumetric BMD (vBMD), bone geometry, and structure at the non-weight-bearing distal radius and weight-bearing distal tibia. Results: Participants with AN had lower WBLH and hip aBMD z scores than OAs and controls (P < 0.0001). Participants with AN and OAs had lower spine aBMD z scores than controls (P < 0.01). At the radius, total and cortical vBMD, percentage cortical area, and thickness were lower in the AN and OA groups than in controls (P ≤ 0.04); trabecular vBMD was lower in participants with AN than controls. At the tibia, participants with AN had lower measures for most parameters compared with OAs and controls (P < 0.05); OAs had lower cortical vBMD than controls (P = 0.002). Participants with AN and OAs had higher fracture rates than controls. Stress fracture prevalence was highest in OAs (P < 0.0001); nonstress fracture prevalence was highest in participants with AN (P < 0.05). Conclusion: AN is deleterious to bone at all sites and both bone compartments. A high stress fracture rate in OAs, who have comparable WBLH and hip aBMD measures to controls, indicates that BMD in these women may need to be even higher to avoid fractures.

Impaired bone strength estimates at the distal tibia and its determinants in adolescents with anorexia nervosa.

BACKGROUND: Altered bone microarchitecture and higher marrow adipose tissue (MAT) may reduce bone strength. High resolution pQCT (HRpQCT) allows assessment of volumetric BMD (vBMD), and size and microarchitecture parameters of bone, while 1H-magnetic resonance spectroscopy (1H-MRS) allows MAT evaluation. We have reported impaired microarchitecture at the non-weight bearing radius in adolescents with anorexia nervosa (AN) and that these changes may precede aBMD deficits. Data are lacking regarding effects of AN on microarchitecture and strength at the weight-bearing tibia in adolescents and young adults, and the impact of changes in microarchitecture and MAT on strength estimates. OBJECTIVE: To compare strength estimates at the distal tibia in adolescents/young adults with AN and controls in relation to vBMD, bone size and microarchitecture, and spine MAT. DESIGN AND METHODS: This was a cross-sectional study of 47 adolescents/young adults with AN and 55 controls 14-24years old that assessed aBMD and body composition using DXA, and distal tibia vBMD, size, microarchitecture and strength estimates using HRpQCT, extended cortical analysis, individual trabecular segmentation, and finite element analysis. Lumbar spine MAT (1H-MRS) was assessed in a subset of 19 AN and 22 controls. RESULTS: Areal BMD Z-scores were lower in AN than controls. At the tibia, AN had greater cortical porosity, lower total and cortical vBMD, cortical area and thickness, trabecular number, and strength estimates than controls. Within AN, strength estimates were positively associated with lean mass, aBMD, vBMD, bone size and microarchitectural parameters. MAT was higher in AN, and associated inversely with strength estimates. CONCLUSIONS: Adolescents/young adults with AN have impaired microarchitecture at the weight-bearing tibia and higher spine MAT, associated with reduced bone strength.

Macronutrient intake associated with weight gain in adolescent girls with anorexia nervosa.

OBJECTIVE: Adolescents and women with anorexia nervosa (AN) are known to severely restrict total calorie and fat intake. However, data are limited regarding specific macronutrient intake associated with weight gain in AN. OBJECTIVE: To prospectively investigate dietary macronutrient composition associated with weight gain in adolescent girls with AN. METHOD: A prospective naturalistic study of 90 girls 12-18 years old; 45 with AN and 45 healthy normal-weight-controls over a 6-12-month period. Participants completed four-day food diaries and underwent body composition assessment using dual energy X-ray absorptiometry. Weight gain was defined as a ≥10% increase in body mass index (BMI) from baseline. RESULTS: Baseline clinical characteristics did not differ between girls with AN who did not gain weight (AN-0) versus those who did (AN-1) over the following 6-12 month period except for percentage of calories from proteins (p = 0.046). At 6-12 month follow-up, AN-1 consumed a lower percentage of total calories from protein (p = .001), and a higher percentage of total calories from fat (p = .02) compared to AN-0. AN-1 had a significant increase in the percentage of total calories obtained from and poly-unsaturated-fatty acids (PUFA) (p = 0.006) compared to AN-0, between baseline and follow-up. Within the AN group, BMI at follow-up was associated positively with percentage of total calories obtained from fat, MUFA, and PUFA (p < .05) at 6/12 months, and inversely with the percentage of total calories obtained from carbohydrates and proteins (p = .03). DISCUSSION: Consuming a greater proportion of total calories from fat is associated with weight gain in adolescent girls with AN.

Impact of low-weight severity and menstrual status on bone in adolescent girls with anorexia nervosa.

Clinicians currently use different low-weight cut-offs both to diagnose anorexia nervosa (AN) and to determine AN severity in adolescent girls. The purpose of this study was to evaluate the clinical utility of existing cut-offs and severity criteria by determining which are most strongly associated with risk for low bone mineral density (BMD). Height adjusted BMD Z scores were calculated for 352 females: 262 with AN and 90 healthy controls (controls) (12-20.5 years), using data from the BMD in Childhood Study, for the lumbar spine, whole body less head, and total hip. For most cut-offs used to define low weight (5th or 10th BMI percentile, BMI of 17.5 or 18.5, and 85 or 90% of median BMI), AN had lower BMD Z scores than controls. AN at >85 or >90% expected body weight for height (EBW-Ht) did not differ in BMD Z scores from controls, but differed significantly from AN at ≤85 or ≤90% EBW-Ht. Among AN, any amenorrhea was associated with lower BMD. AN had lower BMD than controls across DSM-5 and The Society for Adolescent Health and Medicine (SAHM) severity categories. The SAHM moderate severity classification was differentiated from the mildly malnourished classification by lower BMD at hip and spine sites. Amenorrhea and %EBW-Ht ≤ 85 or ≤ 90% are markers of severity of bone loss within AN. Among severity categories, BMI Z scores (SAHM) may have the greatest utility in assessing the degree of malnutrition in adolescent girls that corresponds to lower BMD.