Weighted Mean Correlation Research Articles

The association between psychological resilience and hair cortisol concentration in adults: A systematic review and meta-analysis.

Resilience measures are typically based on subjective self-assessment, which is prone to bias. Objective biological/physiological measures of resilience are therefore needed. Hair cortisol concentration is a particularly promising candidate as a biomarker for resilience. We conducted a meta-analytic review from inception to April 2023 in PubMed, EMBASE, Cochrane Library, and Psych Info databases. All data were analyzed using a random-effects model. Eight studies were identified that included a total of 1,064 adults. The random effects model demonstrated that resilience and hair cortisol concentration were inversely correlated (r = -0.18, 95% confidence interval [CI] = -0.27 to -0.09) with substantial heterogeneity (I2 = 54.2%, p = 0.03). The inverse association was stronger in those who were age 40 years or younger compared to those who were over 40 years. The correlation coefficients between psychological resilience and hair cortisol concentration among adults assessed by different resilience measures were r = -0.29 (95% CI = -0.49 to -0.08) for the CD-RISC-10; r = -0.21 (95% CI = -0.31 to -0.11) for the CDRISC- 25, and r = -0.08 (95% CI = -0.22 to 0.06) for the BRS. Six of eight studies examined the connection between resilience and perceived stress, where the weighted mean correlation coefficient was r = -0.45 (95% CI = -0.56 to -0.33), with considerable heterogeneity (I2 = 76.2%, p = 0.001). There is a negative association between psychological resilience and hair cortisol concentration based on these eight studies. Additional research, particularly prospective studies, is needed to determine whether hair cortisol concentration can be used as a biomarker for psychological resilience.

Circulating Interleukin-23 Levels in Rheumatoid Arthritis and its Relationship to Disease Activity: a Systematic Review with Meta-Analysis

Background: Rheumatoid arthritis (RA) is a chronic and systemic autoimmune disease that is characterized by severe synovial inflammation, cartilage erosion, bone loss, and generalized vasculopathy. Although the immunologic mechanism of RA is still unclear, it is now thought to be a primarily Th17-driven disease. Along with other factors, IL-23 stimulates the expansion of Th17 cells from naive CD4+ T cells. Objective: The objective of this study is to assess the circulating levels of interleukin (IL)-23 in rheumatoid arthritis (RA) and determine the correlation between plasma/serum IL-23 levels and disease activity. So, we performed a systematic review with meta-analysis comparing plasma/serum IL-23 levels between patients with RA and controls and examined correlation coefficients between circulating IL-23 levels and disease activity Subjects and Methods: Using the following keywords: lenterleukin-23, IL-23, and rheumatoid arthritis, a comprehensive literature search was carried out in the following databases: PubMed, Scopus, Google Scholar, and Web of Science. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses standards were followed, and the review was registered in the PROSPERO International prospective register of systematic reviews with registration number CRD42022345901. Results were reported as standardized mean differences (SMDs) with a 95% confidence interval. All statistical analysis was performed using StatsDirect statistical software version 3.0.0 (StatsDirect Ltd., Cheshire, UK). A sensitivity analysis was conducted using the leave-one-out approach to test the robustness of the results. Results: The total sample size for the RA group included in our review was 408 cases, while the control group sample size was 244 cases. The serum IL-23 level in the RA group was significantly higher than the control group (pooled SMD = 3.5, 95% CI; 2.1: 4.8, P < 0.0001) as compared to the control group. There were 8 studies with a total sample size of 402 that reported the correlation between IL-23 and DAS28-based RA activity. According to our findings, a significantly positive correlation between IL-23 and DAS28-based RA activity was found, with a weighted mean correlation of 0.57 (95% CI; 0.4: 0.75, P < 0.0001). Conclusion: Our meta-analysis has shown that IL-23 circulatory levels are higher in RA patients and that there is a significant positive correlation between IL-23 and disease activity. Our findings emphasize the role that IL-23 may have in RA. More studies may be required to fully comprehend the involvement of IL-23 in RA.

Mind the Gap Between Comprehension and Metacomprehension: Meta-Analysis of Metacomprehension Accuracy and Intervention Effectiveness

Research has consistently demonstrated that learners are strikingly poor at metacognitively monitoring their learning and comprehension of texts. The aim of the present meta-analysis is to explore three important questions about metacomprehension: (a) To what extent can people accurately discriminate well-learned texts from less well learned ones? (b) What are the (meta)cognitive causes of poor metacomprehension accuracy? and (c) What interventions improve the accuracy of metacomprehension judgments? In total, the meta-analysis integrated 502 effects and data from 15,889 participants across 115 studies to assess these questions. The results showed a weighted mean correlation of .178 for nonintervention effects. Many interventions were shown to be effective, such as delayed summary writing and delayed keyword generation. In addition, combining different interventions tended to generate additive benefits. The findings support the transfer-appropriate monitoring account, the situation model framework, and the poor-comprehension theory as explanations for why metacomprehension accuracy is typically poor. Practical implications are discussed.

Subjective cognitive complaints and subjective cognition following electroconvulsive therapy for depression: A systematic review and meta-analysis.

Subjective cognitive complaints represent a leading reason for suboptimal prescription of electroconvulsive therapy, the most acutely effective treatment for depression. However, research findings regarding their presentation are conflicting. To describe, quantify and explain the variability in subjective cognitive complaints and subjective cognition following electroconvulsive therapy for depression. We searched systematically PubMed, Embase, PsycARTICLES, CINAHL and relevant reviews for research published from 1 January 1972 to 31 August 2020. We included all independent studies of patients whose subjective cognition was assessed following brief-pulse electroconvulsive therapy for depression. Three meta-analyses were conducted to quantify: (1) the prevalence of patients presenting with cognitive complaints following electroconvulsive therapy; (2) the pre-post electroconvulsive therapy change in subjective cognition and (3) the association between change in depressive symptoms and change in cognitive complaints. Effect sizes were calculated using random-effects models. Eight prespecified demographic and clinical moderators of between-study variability were assessed using sub-group analyses and meta-regressions. Data from 72 studies including 5699 participants were meta-analysed. Weighted mean prevalence of patients with cognitive complaints was 48.1% (95% confidence interval = [42.3%, 53.9%]). The type of subjective measure used significantly impacted the pre-post electroconvulsive therapy change in subjective cognition, showing, respectively, large improvement (g = 0.81; 95% confidence interval = [0.59, 1.03]) after electroconvulsive therapy with the Squire Self-Rating Scale of Memory and small worsening (g = -0.48; 95% confidence interval = [-0.70, -0.26]) with 1-item memory scales. The strongest predictors of improved post-electroconvulsive therapy subjective cognition were increased age and larger post-electroconvulsive therapy decrease in depressive symptoms. The weighted mean correlation between pre-post electroconvulsive therapy decrease in depressive symptoms and pre-post electroconvulsive therapy decrease in cognitive complaints was 0.46 (95% confidence interval = [0.39, 0.53]). Variability in subjective cognition following electroconvulsive therapy is mostly explained by the degree of post-treatment persisting depression and by the subjective assessment used. Scales measuring exclusively subjective worsening present limited clinical utility and instruments allowing the detection of both improvement and worsening in subjective cognition should be preferred.

A meta-analysis of police leadership and organizational effectiveness: focusing on the South Korean police

A meta-analysis of police leadership and organizational effectiveness: focusing on the South Korean police

Child Distress Expression and Regulation Behaviors: A Systematic Review and Meta-Analysis.

The goal of the current study was to review and meta-analyze the literature on relationships between child distress expression behaviors (e.g., cry) and three clusters of child distress regulation behaviors (disengagement of attention, parent-focused behaviors, and self-soothing) in the first three years of life. This review was registered with PROSPERO (CRD42020157505). Unique abstracts were identified through Medline, Embase, and PsycINFO (n = 13,239), and 295 studies were selected for full-text review. Studies were included if they provided data from infants or toddlers in a distress task, had distinct behavioral measures of distress expression and one of the three distress regulation clusters, and assessed the concurrent association between them. Thirty-one studies were included in the meta-analysis and rated on quality. Nine separate meta-analyses were conducted, stratified by child age (first, second, and third year) and regulation behavior clusters (disengagement of attention, parent-focused, and self-soothing). The weighted mean correlations for disengagement of attention behaviors were −0.28 (year 1), −0.44 (year 2), and −0.30 (year 3). For parent-focused behaviors, the weighted mean effects were 0.00 (year 1), 0.20 (year 2), and 0.11 (year 3). Finally, the weighted mean effects for self-soothing behaviors were −0.23 (year 1), 0.25 (year 2), and −0.10 (year 3). The second year of life showed the strongest relationships, although heterogeneity of effects was substantial across the analyses. Limitations include only analyzing concurrent relationships and lack of naturalistic distress paradigms in the literature.

On the Association Between Trauma-Related Shame and Symptoms of Psychopathology: A Meta-Analysis

Background A number of studies have identified significant associations between trauma-related shame and psychopathology including posttraumatic stress disorder (PTSD), dissociation, and depression. The aim of this paper was to assess the extent to which trauma-related shame is associated with psychological distress across populations (e.g., veterans, college students, women, clinical samples) and offer via meta-analyses a preliminary conclusion about the importance of assessing trauma-related shame. Methods Records in Academic Search Complete, MedLine, MedLine Complete, PILOTS, PsycINFO, PsychTests, and PubMed were reviewed. Authors identified 25 studies that met the following inclusion criteria: (1) reported findings of an empirical study with quantitative results; (2) included any measurement of a trauma-related shame; and (3) included any measure of psychological distress or psychological symptoms. Data were extracted using a structured protocol, and random effects meta-analyses were calculated. Findings There were moderate weighted mean correlations between trauma-related shame and symptoms of psychopathology (r = 0.44), trauma-related distress (r = 0.49), and depression (r = 0.35). There was significant heterogeneity among studies. Neither study quality nor sample characteristics were significant moderators. Conclusion This meta-analysis demonstrated robust associations between trauma-related shame and symptoms of psychopathology broadly as well as trauma-related distress and depression. The findings underscore the importance of explicitly assessing trauma-related shame as part of standard care for trauma survivors who present for treatment. Several treatments explicitly address the role of shame and have demonstrated efficacy for reducing symptoms of trauma-related distress.

Convergent Validity of CR100-Based Session Ratings of Perceived Exertion in Elite Youth Football Players of Different Ages.

To assess the convergent validity of internal load measured with the CR100 scale in youth football players of 3 age groups. A total of 59 players, age 12-17years, from the youth academy of a professional football club were involved in this study. Convergent validity was examined by calculating the correlation between session ratings of perceived exertion (sRPE) and Edwards load, a commonly used load index derived from the heart rate, with the data originating from 1 competitive season. The magnitude of the relationship between sRPE and Edwards load was obtained with weighted mean correlations and by assessing the effect of the change of the Edwards load on sRPE. Differences between the individuals' intercepts and slopes were assessed by interpreting the SD representing the random effects (player identity and the interaction of player identity and scaled Edwards load). Probabilistic decisions about true (infinite sample) magnitudes accounting for sampling uncertainty were based on 1-sided hypothesis tests of substantial magnitudes, followed by reference Bayesian analysis. Very high relationships exist between the sRPE and Edwards load across all age groups, with no meaningful differences in the magnitudes of the relationships between groups. Moderate to large differences between training sessions and games were found in the slopes of the relationships between the sRPE and Edwards load in all age groups. Finally, mostly small to moderate differences were observed between individuals for the intercepts and slopes of the relationships between the sRPE and Edwards load. Practitioners working in youth team sports can safely use the CR100 scale to track internal load.

How effective is teamwork really? The relationship between teamwork and performance in healthcare teams: a systematic review and meta-analysis

ObjectivesTo investigate the relationship between teamwork and clinical performance and potential moderating variables of this relationship.DesignSystematic review and meta-analysis.Data sourcePubMed was searched in June 2018 without a limit on the...

A Critical Review and Meta-Analysis of the Associations Between Acculturation and Alcohol Use Outcomes Among Hispanic Americans.

Acculturation has been studied as one key sociocultural determinant that helps explain ethnic disparities in alcohol use outcomes among Hispanic Americans. Primary studies and other systematic reviews have found between-study inconsistencies regarding the extent to which acculturation is associated with alcohol use outcomes among Hispanic Americans. To better examine whether acculturation is distinctly linked to drinker status, drinking frequency, volume, intensity, binge drinking, and hazardous alcohol use/drinking problems, and to identify individual and methodological factors that moderate these associations, we conducted a comprehensive research synthesis. A systematic review was conducted on research pertaining to the associations between acculturation and alcohol use among Hispanics. We included 88 independent study samples (N=68,282) coded from 68 manuscripts published in 1987 to 2017. Standard and robust variance estimation (RVE) meta-analyses were conducted to calculate the correlations between acculturation and overall alcohol use. We also conducted a series of analyses to examine the weighted mean correlations between acculturation and 6 specific drinking outcomes. We found a statistically significant correlation between acculturation and overall alcohol use (r=0.09, p<0.001). Acculturation was associated with drinker status (r=0.10, p<0.001), drinking intensity (r=0.09, p=0.001), binge drinking (r=0.05, p=0.006), and hazardous alcohol use/drinking problems (r=0.06, p=0.006), but not drinking frequency (r=0.02, p=0.56) or volume (r=0.01, p=0.73). Gender, acculturation dimension, acculturation domain, age group, and sampling settings were found to explain between-study variability in some of these associations. Findings show small relations between acculturation and various alcohol use outcomes, but the effects are relatively more robust among Hispanic women, adults, and when studies measured U.S. cultural orientation, linguistic acculturation, and behavioral practices.

Social network site use and academic achievement: A meta-analysis

This meta-analysis examines the relation between use of social network sites and academic achievement. Thirty studies consisting of 21,367 participants are identified. The weighted mean correlation between use of social network sites and academic achievement is r¯ = −0.07. The weighted mean correlation is negligible (r¯ = −0.02) for studies assessing Facebook use, and small (r¯ = −0.12) for studies measuring use of all social network sites. Further, the weighted mean correlation is small (r¯ = −0.10) for studies assessing the duration of use, and close to zero (r¯ = −0.01) for studies measuring visiting frequency. The implication of the research for the relation between social network site use and academic achievement is discussed.

Correlates of perceived stigma for people living with epilepsy: A meta-analysis.

Epilepsy, one of the most common, serious chronic neurological diseases, is accompanied by different levels of perceived stigma that affects people in almost all age groups. This stigma can negatively impact the physical and mental health of people living with epilepsy (PLWE). Good knowledge of perceived stigma for PLWE is important. In this study, we conducted a meta-analysis to identify the correlates of perceived stigma for PLWE. Studies on factors associated with perceived stigma for PLWE, including sociodemographic, psychosocial, and disease-related variables, were searched in PubMed, PsychINFO, EMBASE, and Web of Science. Nineteen variables (k>1) were included in the meta-analysis. For sociodemographic characteristics, findings revealed that the significant weighted mean correlation (R) for "residence" and "poor financial status" were 0.177 and 0.286, respectively. For disease-related characteristics, all variables of significance, including "seizure severity," "seizure frequency," "number of medicines," and "adverse event" (R ranging from 0.190 to 0.362), were positively correlated with perceived stigma. For psychosocial characteristics, "depression" and "anxiety" with R values of 0.414 and 0.369 were significantly associated with perceived stigma. In addition, "social support," "quality of life (QOLIE-31,89)," "knowledge," and "attitude," with R values ranging from -0.444 to -0.200 indicating negative correlation with perceived stigma. The current meta-analysis evaluated the correlates of perceived stigma for PLWE. Results can serve as a basis for policymakers and healthcare professionals for formulating health promotion and prevention strategies.

Systematic Review and Meta-Analysis of Predictors of Military Task Performance: Maximal Lift Capacity.

Hydren, JR, Borges, AS, and Sharp, MA. Systematic review and meta-analysis of predictors of military task performance: maximal lift capacity. J Strength Cond Res 31(4): 1142-1164, 2017-Physical performance tests (e.g., physical employment tests, return-to-duty tests) are commonly used to predict occupational task performance to assess the ability of individuals to do a job. The purpose of this systematic review was to identify predictive tests that correlate well with maximal lifting capacity in military personnel. Three databases were searched and experts in the field were contacted, resulting in the identification of 9 reports confined to military personnel that presented correlations between predictor tests and job tasks that measured maximal lift capacity. These 9 studies used 9 variations of a maximal lift capacity test, which were pooled to evaluate comparisons. The predictive tests were categorized into 10 fitness domains, which in ranked order were as follows: body mass and composition, absolute aerobic capacity, dynamic strength, power, isometric strength, strength-endurance, speed, isokinetic strength, flexibility, and age. Limitations of these data include a restricted age range (95% confidence interval [95% CI], 20-35; no correlations to maximal lift capacity) and the limited number of comparisons available within the cited studies. Weighted mean correlations ((Equation is included in full-text article.)) and 95% CI were calculated for each test. Lean body mass (kg) was the strongest overall predictor ((Equation is included in full-text article.); 95% CI, 0.697-0.966). Tests of dynamic strength had stronger correlations than strength endurance ((Equation is included in full-text article.), 95% CI, 0.69-0.89 vs. (Equation is included in full-text article.), 95% CI, 0.21-0.61). The following 6 domains of physical performance predictive tests had pooled correlations of 0.40 or greater for combined-sex samples: dynamic strength, power, isometric strength, strength endurance, speed, and isokinetic strength. Anthropometric measures explain 24-54% of maximal lift capacity variance, and lean body mass alone accounts for ∼69%. This review provides summarized information to assist in the selection of predictive tests for maximal lifting capacity in military personnel.

Are there vocal cues to human developmental stability? Relationships between facial fluctuating asymmetry and voice attractiveness

Fluctuating asymmetry (FA), deviation from perfect bilateral symmetry, is thought to reflect an organism's relative inability to maintain stable morphological development in the face of environmental and genetic stressors. Previous research has documented negative relationships between FA and attractiveness judgments in humans, but scant research has explored relationships between the human voice and this putative marker of genetic quality in either sex. Only one study (and in women only) has explored relationships between vocal attractiveness and asymmetry of the face, a feature-rich trait space central in prior work on human genetic quality and mate choice. We therefore examined this relationship in three studies comprising 231 men and 240 women from two Western samples as well as Hadza hunter–gatherers of Tanzania. Voice recordings were collected and rated for attractiveness, and FA was computed from two-dimensional facial images as well as, for a subset of men, three-dimensional facial scans. Through meta-analysis of our results and those of prior studies, we found a negative association between FA and vocal attractiveness that was highly robust and statistically significant whether we included effect sizes from previously published work, or only those from the present research, and regardless of the inclusion of any individual sample or method of assessing FA (e.g., facial or limb FA). Weighted mean correlations between FA and vocal attractiveness across studies were −.23 for men and −.29 for women. This research thus offers strong support for the hypothesis that voices provide cues to genetic quality in humans.

A meta-analysis of the effectiveness of the low-ball compliance-gaining procedure

IntroductionThe low-ball (Cialdini et al., 1978)1 is a compliance-gaining technique consisting of making an attractive initial offer to get a person to agree to the request and then making the terms less favorable (target request). Objective and methodsThe effectiveness of this technique was evaluated in a meta-analysis using 17 references, 23 studies, 44 subgroups and a combined sample size of 4733. ResultsAnalysis reported a weighted mean correlation coefficient of r=.16 and a weighted mean odds ratio of OR=2.47. Moderator analysis reported that the low-ball was more efficient with a high cost request in terms of effort for the participant and when the solicitation of the target request is deferred. ConclusionThese findings appeared congruent with commitment theoretical explanation of the low-ball.

Early Exposure to Nonnutritive Sweeteners and Long-term Metabolic Health: A Systematic Review.

Nonnutritive sweetener (NNS) consumption is increasing among children, yet its long-term health impact is unclear, particularly when exposure occurs during early life. To synthesize evidence from prospective studies evaluating the association of early-life NNS exposure and long-term metabolic health. Medline, Embase, and Cochrane Library (inception to July 2015). We aimed to include randomized controlled trials (RCTs) evaluating NNS-based interventions and prospective cohort studies reporting NNS exposure among pregnant women, infants, or children (<12 years of age), with a minimum study duration of 6 months. The primary outcome was BMI; secondary outcomes included growth velocity, overweight/obesity, adiposity, and adverse metabolic effects. Study quality and risk of bias were evaluated using validated assessment tools. We identified 6 eligible cohort studies and 2 RCTs (n = 15,641 children). Half of the cohorts reported increasing weight gain or fat mass accumulation with increasing NNS intake, and pooled data from 2 cohorts showed a significant correlation with BMI gain (weighted mean correlation 0.023, 95% confidence interval 0.006 to 0.041). RCTs reported contradictory effects on weight change in children receiving NNSs. No eligible studies evaluated prenatal or infant NNS exposure. Meta-analysis was limited because of the small number of eligible studies and heterogeneity of populations and outcomes. There is limited and inconsistent evidence of the long-term metabolic effects of NNS exposure during gestation, infancy, and childhood. Further research is needed to inform recommendations for the use of NNSs in this sensitive population.

Exploring the Relationships Between Problem Gambling and ADHD: A Meta-Analysis

Objective: At present, there are inconsistencies in the literature pertaining to the association between ADHD and problem gambling. This study utilized meta-analytic techniques to clarify the association between symptoms of problem gambling and symptoms of ADHD. Method: Several meta-analyses were conducted using a random effects model. PsycINFO, PubMed, ProQuest Dissertations & Theses, and Google Scholar were searched for relevant studies. Results: The weighted mean correlation between ADHD symptomology and gambling severity was r = .17, 95% confidence interval (CI) = [0.12, 0.22], p < .001. Mean age of the sample was the only moderator to approach significance, with greater age being linked to a stronger relationship between symptoms of ADHD and gambling severity. Conclusion: Clinicians needs to be cognizant of the greater risk of ADHD symptoms when working with problem gamblers and vice versa.

Abusive Supervision: A Meta-Analysis and Empirical Review

We conducted a meta-analysis and empirical review of abusive supervision research in order to derive meta-analytic population estimates for the relationships between perceptions of abusive supervision and numerous demographic, justice, individual difference, leadership, and outcome variables. The use of psychometric correction enabled us to provide weighted mean correlations and population correlation estimates that accounted for attenuation due to measurement error and sampling error variance. Also, we conducted sensitivity analyses that removed the effects of large samples from analyses. Then, we conducted subgroup analyses using samples drawn from the United States to provide population correlation estimates that corrected for attenuation due to measurement error, sampling error variance, and indirect range restriction. Finally, we examined measurement artifacts resulting from various adaptations of Tepper’s abusive supervision measure. The results reveal that although the associations between perceptions of abusive supervision and outcome variables appear to be universally negative, the magnitude of the relationships between perceptions of abusive supervision and antecedent and outcome variables varies according to the design features of studies. Contributions to theory and practice, strengths and limitations, and directions for future research are discussed.

A Meta-Analysis of Studies on Protection Motivation Theory and Information Security Behaviour

Individuals' willingness to take security precautions is imperative to their own information security and the information security of the organizations they work within. This paper presents a meta-analysis of the protection motivation theory (PMT) to assess how its efficacy is influenced by the information security behavior it is applied to. It investigates if the PMT explains information security behavior better if: 1) The behavior is voluntary? 2) The threat and coping method is concrete or specific? 3) The information security threat is directed to the person itself? Synthesized data from 28 surveys suggests that the answers to all three questions are yes. Weighted mean correlation coefficients are on average 0.03 higher for voluntary behavior than mandatory behavior, 0.05 higher for specific behaviors than studies of general behaviors, 0.08 higher to threat appraisal when the threat targets the individual person instead of the person's organization or someone else.

Low-calorie sweeteners and body weight and composition: a meta-analysis of randomized controlled trials and prospective cohort studies , ,

Background: Replacement of caloric sweeteners with lower- or no-calorie alternatives may facilitate weight loss or weight maintenance by helping to reduce energy intake; however, past research examining low-calorie sweeteners (LCSs) and body weight has produced mixed results.Objective: The objective was to systematically review and quantitatively evaluate randomized controlled trials (RCTs) and prospective cohort studies, separately, that examined the relation between LCSs and body weight and composition.Design: A systematic literature search identified 15 RCTs and 9 prospective cohort studies that examined LCSs from foods or beverages or LCSs consumed as tabletop sweeteners. Meta-analyses generated weighted mean differences in body weight and composition values between the LCS and control groups among RCTs and weighted mean correlations for LCS intake and these parameters among prospective cohort studies.Results: In RCTs, LCSs modestly but significantly reduced all outcomes examined, including body weight (−0.80 kg; 95% CI: −1.17, −0.43), body mass index [BMI (in kg/m2): −0.24; 95% CI: −0.41, −0.07], fat mass (−1.10 kg; 95% CI: −1.77, −0.44), and waist circumference (−0.83 cm; 95% CI: −1.29, −0.37). Among prospective cohort studies, LCS intake was not associated with body weight or fat mass, but was significantly associated with slightly higher BMI (0.03; 95% CI: 0.01, 0.06).Conclusions: The current meta-analysis provides a rigorous evaluation of the scientific evidence on LCSs and body weight and composition. Findings from observational studies showed no association between LCS intake and body weight or fat mass and a small positive association with BMI; however, data from RCTs, which provide the highest quality of evidence for examining the potentially causal effects of LCS intake, indicate that substituting LCS options for their regular-calorie versions results in a modest weight loss and may be a useful dietary tool to improve compliance with weight loss or weight maintenance plans.