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BMJ (Clinical Research Ed.) Nov 2017To assess whether weight loss interventions for adults with obesity affect all cause, cardiovascular, and cancer mortality, cardiovascular disease, cancer, and body... (Meta-Analysis)
Meta-Analysis Review
To assess whether weight loss interventions for adults with obesity affect all cause, cardiovascular, and cancer mortality, cardiovascular disease, cancer, and body weight. Systematic review and meta-analysis of randomised controlled trials (RCTs) using random effects, estimating risk ratios, and mean differences. Heterogeneity investigated using Cochran's Q and I statistics. Quality of evidence assessed by GRADE criteria. Medline, Embase, the Cochrane Central Register of Controlled Trials, and full texts in our trials' registry for data not evident in databases. Authors were contacted for unpublished data. RCTs of dietary interventions targeting weight loss, with or without exercise advice or programmes, for adults with obesity and follow-up ≥1 year. 54 RCTs with 30 206 participants were identified. All but one trial evaluated low fat, weight reducing diets. For the primary outcome, high quality evidence showed that weight loss interventions decrease all cause mortality (34 trials, 685 events; risk ratio 0.82, 95% confidence interval 0.71 to 0.95), with six fewer deaths per 1000 participants (95% confidence interval two to 10). For other primary outcomes moderate quality evidence showed an effect on cardiovascular mortality (eight trials, 134 events; risk ratio 0.93, 95% confidence interval 0.67 to 1.31), and very low quality evidence showed an effect on cancer mortality (eight trials, 34 events; risk ratio 0.58, 95% confidence interval 0.30 to 1.11). Twenty four trials (15 176 participants) reported high quality evidence on participants developing new cardiovascular events (1043 events; risk ratio 0.93, 95% confidence interval 0.83 to 1.04). Nineteen trials (6330 participants) provided very low quality evidence on participants developing new cancers (103 events; risk ratio 0.92, 95% confidence interval 0.63 to 1.36). Weight reducing diets, usually low in fat and saturated fat, with or without exercise advice or programmes, may reduce premature all cause mortality in adults with obesity. PROSPERO CRD42016033217.
Topics: Adult; Body Mass Index; Cardiovascular Diseases; Diet, Reducing; Exercise; Female; Humans; Male; Middle Aged; Neoplasms; Obesity; Quality of Life; Randomized Controlled Trials as Topic; Survival Analysis; United Kingdom; Weight Loss
PubMed: 29138133
DOI: 10.1136/bmj.j4849 -
Journal of Hepatology Aug 2023The prevalence of non-alcoholic fatty liver disease (NAFLD) is increasing. We aimed to estimate the pooled global NAFLD incidence. (Meta-Analysis)
Meta-Analysis
BACKGROUND & AIMS
The prevalence of non-alcoholic fatty liver disease (NAFLD) is increasing. We aimed to estimate the pooled global NAFLD incidence.
METHODS
We performed a systematic review and meta-analysis of cohort studies of adults without NAFLD at baseline to evaluate the global incidence of ultrasound-diagnosed NAFLD.
RESULTS
A total of 63 eligible studies (1,201,807 persons) were analyzed. Studies were from Mainland China/Hong Kong (n = 26), South Korea (n = 22), Japan (n = 14), other (n = 2, Sri Lanka, Israel); 63.8% were clinical center studies; median study year 2000 to 2016; 87% were good quality. Among the 1,201,807 persons at risk, 242,568 persons developed NAFLD, with an incidence rate of 4,612.8 (95% CI 3,931.5-5,294.2) per 100,000 person-years and no statistically significant differences by study sample size (p = 0.90) or study setting (p = 0.055). Males had higher incidence vs. females (5,943.8 vs. 3,671.7, p = 0.0013). Both the obese (vs. non-obese) and the overweight/obese groups (vs. normal weight) were about threefold more likely to develop NAFLD (8,669.6 vs. 2,963.9 and 8,416.6 vs. 3,358.2, respectively) (both p <0.0001). Smokers had higher incidence than non-smokers (8,043.2 vs. 4,689.7, p = 0.046). By meta-regression, adjusting for study year, study setting, and study location, study period of 2010 or after and study setting were associated with increased incidence (p = 0.010 and p = 0.055, respectively). By country, China had a higher NAFLD incidence compared to non-China regions (p = 0.012) and Japan a lower incidence compared to non-Japan regions (p = 0.005).
CONCLUSIONS
NAFLD incidence is increasing with a current estimate of 4,613 new cases per 100,000 person-years. Males and overweight/obese individuals had significantly higher incidence rates compared to females and those of normal weight. Public health interventions for prevention of NAFLD are needed with a special emphasis on males, overweight/obese individuals, and higher risk regions.
IMPACT AND IMPLICATIONS
Non-alcoholic fatty liver disease (NAFLD) affects approximately 30% of people worldwide and appears to be increasing, but data to estimate the incidence rate are limited. In this meta-analytic study of over 1.2 million people, we estimated an incidence rate of NAFLD of 46.13 per 1,000 person-years with significant differences by sex, BMI, geography, and time-period. As treatment options for NAFLD remain limited, prevention of NAFLD should remain the focus of public health strategies. Studies such as these can help policy makers in determining which and whether their interventions are impactful.
Topics: Male; Adult; Female; Humans; Non-alcoholic Fatty Liver Disease; Incidence; Overweight; Obesity; Cohort Studies
PubMed: 37040843
DOI: 10.1016/j.jhep.2023.03.040 -
Journal of Advanced Nursing May 2018To summarize the associations between weight stigma and physiological and psychological health for individuals who are overweight or obese. (Review)
Review
AIM
To summarize the associations between weight stigma and physiological and psychological health for individuals who are overweight or obese.
BACKGROUND
Weight stigma can be defined as individuals experiencing verbal or physical abuse secondary to being overweight or obese. Weight stigma has negative consequences for both physiological and psychological health.
DESIGN
A quantitative systematic review.
DATA SOURCES
PubMed, PsycINFO, CINAHL and MEDLINE from 1 January 2008 - 30 July 2016.
REVIEW METHODS
A systematic review was conducted using the Cochrane Collaboration guidelines, the PRISMA statement guidelines and the quality assessment from the National Heart, Lung and Blood Institute. Inclusion criteria consisted of quantitative studies that examined the associations between weight stigma and physiological and psychological health outcomes in adults who were overweight or obese. Exclusion criteria consisted of qualitative studies, literature reviews, expert opinions, editorials and reports on weight stigma without health outcomes or with behavioural outcomes and intervention studies that reduced weight stigma. A quality appraisal of the selected studies was conducted.
RESULTS
A total of 33 studies met the eligibility criteria. Weight stigma was positively associated with obesity, diabetes risk, cortisol level, oxidative stress level, C-reactive protein level, eating disturbances, depression, anxiety, body image dissatisfaction and negatively associated with self-esteem among overweight and obese adults.
CONCLUSION
Weight stigma is associated with adverse physiological and psychological outcomes. This conclusion highlights the need to increase public and professional awareness about the issue of weight stigma and the importance of the further development of assessment and prevention strategies of weight stigma.
Topics: Adult; Aged; Aged, 80 and over; Female; Humans; Male; Middle Aged; Obesity; Overweight; Self Concept; Social Stigma
PubMed: 29171076
DOI: 10.1111/jan.13511 -
Nutrients Aug 2022Alterations in body composition, in particular sarcopenia and sarcopenic obesity, are complications of liver cirrhosis associated with adverse outcomes. This systematic... (Review)
Review
Alterations in body composition, in particular sarcopenia and sarcopenic obesity, are complications of liver cirrhosis associated with adverse outcomes. This systematic review aimed to evaluate the effect of diet and/or exercise interventions on body composition (muscle or fat) in adults with cirrhosis. Five databases were searched from inception to November 2021. Controlled trials of diet and/or exercise reporting at least one body composition measure were included. Single-arm interventions were included if guideline-recommended measures were used (computed tomography/magnetic resonance imaging, dual-energy X-ray absorptiometry, bioelectrical impedance analysis, or ultrasound). A total of 22 controlled trials and 5 single-arm interventions were included. Study quality varied (moderate to high risk of bias), mainly due to lack of blinding. Generally, sample sizes were small ( = 6-120). Only one study targeted weight loss in an overweight population. When guideline-recommended measures of body composition were used, the largest improvements occurred with combined diet and exercise interventions. These mostly employed high protein diets with aerobic and or resistance exercises for at least 8 weeks. Benefits were also observed with supplementary branched-chain amino acids. While body composition in cirrhosis may improve with diet and exercise prescription, suitably powered RCTs of combined interventions, targeting overweight/obese populations, and using guideline-recommended body composition measures are needed to clarify if sarcopenia/sarcopenic obesity is modifiable in patients with cirrhosis.
Topics: Adult; Body Composition; Diet; Exercise Therapy; Humans; Liver Cirrhosis; Obesity; Overweight; Sarcopenia
PubMed: 36014871
DOI: 10.3390/nu14163365 -
The International Journal of Behavioral... Mar 2017This systematic review aims to explain the heterogeneity in results of interventions to promote physical activity and healthy eating for overweight and obese adults, by... (Comparative Study)
Comparative Study Meta-Analysis Review
PURPOSE
This systematic review aims to explain the heterogeneity in results of interventions to promote physical activity and healthy eating for overweight and obese adults, by exploring the differential effects of behaviour change techniques (BCTs) and other intervention characteristics.
METHODS
The inclusion criteria specified RCTs with ≥ 12 weeks' duration, from January 2007 to October 2014, for adults (mean age ≥ 40 years, mean BMI ≥ 30). Primary outcomes were measures of healthy diet or physical activity. Two reviewers rated study quality, coded the BCTs, and collected outcome results at short (≤6 months) and long term (≥12 months). Meta-analyses and meta-regressions were used to estimate effect sizes (ES), heterogeneity indices (I) and regression coefficients.
RESULTS
We included 48 studies containing a total of 82 outcome reports. The 32 long term reports had an overall ES = 0.24 with 95% confidence interval (CI): 0.15 to 0.33 and I = 59.4%. The 50 short term reports had an ES = 0.37 with 95% CI: 0.26 to 0.48, and I = 71.3%. The number of BCTs unique to the intervention group, and the BCTs goal setting and self-monitoring of behaviour predicted the effect at short and long term. The total number of BCTs in both intervention arms and using the BCTs goal setting of outcome, feedback on outcome of behaviour, implementing graded tasks, and adding objects to the environment, e.g. using a step counter, significantly predicted the effect at long term. Setting a goal for change; and the presence of reporting bias independently explained 58.8% of inter-study variation at short term. Autonomy supportive and person-centred methods as in Motivational Interviewing, the BCTs goal setting of behaviour, and receiving feedback on the outcome of behaviour, explained all of the between study variations in effects at long term.
CONCLUSION
There are similarities, but also differences in effective BCTs promoting change in healthy eating and physical activity and BCTs supporting maintenance of change. The results support the use of goal setting and self-monitoring of behaviour when counselling overweight and obese adults. Several other BCTs as well as the use of a person-centred and autonomy supportive counselling approach seem important in order to maintain behaviour over time.
TRIAL REGISTRATION
PROSPERO CRD42015020624.
Topics: Adult; Behavior Therapy; Diet, Healthy; Exercise; Feedback; Feeding Behavior; Health Behavior; Health Promotion; Humans; Motivation; Obesity; Overweight
PubMed: 28351367
DOI: 10.1186/s12966-017-0494-y -
Journal of the Academy of Nutrition and... Sep 2015The majority of people with type 2 diabetes are overweight or obese, and weight loss is a recommended treatment strategy. A systematic review and meta-analysis was... (Meta-Analysis)
Meta-Analysis Review
The majority of people with type 2 diabetes are overweight or obese, and weight loss is a recommended treatment strategy. A systematic review and meta-analysis was undertaken to answer the following primary question: In overweight or obese adults with type 2 diabetes, what are the outcomes on hemoglobin A1c (HbA1c) from lifestyle weight-loss interventions resulting in weight losses greater than or less than 5% at 12 months? Secondary questions are: What are the lipid (total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides) and blood pressure (systolic and diastolic) outcomes from lifestyle weight-loss interventions resulting in weight losses greater than or less than 5% at 12 months? And, what are the weight and metabolic outcomes from differing amounts of macronutrients in weight-loss interventions? Inclusion criteria included randomized clinical trial implementing weight-loss interventions in overweight or obese adults with type 2 diabetes, minimum 12-month study duration, a 70% completion rate, and an HbA1c value reported at 12 months. Eleven trials (eight compared two weight-loss interventions and three compared a weight-loss intervention group with a usual care/control group) with 6,754 participants met study criteria. At 12 months, 17 study groups (8 categories of weight-loss intervention) reported weight loss <5% of initial weight (-3.2 kg [95% CI: -5.9, -0.6]). A meta-analysis of the weight-loss interventions reported nonsignificant beneficial effects on HbA1c, lipids, or blood pressure. Two study groups reported a weight loss of ≥5%: a Mediterranean-style diet implemented in newly diagnosed adults with type 2 diabetes and an intensive lifestyle intervention implemented in the Look AHEAD (Action for Health in Diabetes) trial. Both included regular physical activity and frequent contact with health professionals and reported significant beneficial effects on HbA1c, lipids, and blood pressure. Five trials (10 study groups) compared weight-loss interventions of differing amounts of macronutrients and reported nonsignificant differences in weight loss, HbA1c, lipids, and blood pressure. The majority of lifestyle weight-loss interventions in overweight or obese adults with type 2 diabetes resulted in weight loss <5% and did not result in beneficial metabolic outcomes. A weight loss of >5% appears necessary for beneficial effects on HbA1c, lipids, and blood pressure. Achieving this level of weight loss requires intense interventions, including energy restriction, regular physical activity, and frequent contact with health professionals. Weight loss for many overweight or obese individuals with type 2 diabetes might not be a realistic primary treatment strategy for improved glycemic control. Nutrition therapy for individuals with type 2 diabetes should encourage a healthful eating pattern, a reduced energy intake, regular physical activity, education, and support as primary treatment strategies.
Topics: Combined Modality Therapy; Diabetes Mellitus, Type 2; Diet, Diabetic; Diet, Reducing; Glycated Hemoglobin; Humans; Hyperglycemia; Life Style; Motor Activity; Obesity; Overweight; Patient Education as Topic; Randomized Controlled Trials as Topic; Weight Loss
PubMed: 25935570
DOI: 10.1016/j.jand.2015.02.031 -
International Journal of Environmental... Jan 2019With the dramatic growth of the Chinese economy, the number of children/adolescents with being overweight/having obesity is increasing, which has a certain impact on... (Meta-Analysis)
Meta-Analysis
The Prevalence of Depression and Anxiety Symptoms among Overweight/Obese and Non-Overweight/Non-Obese Children/Adolescents in China: A Systematic Review and Meta-Analysis.
With the dramatic growth of the Chinese economy, the number of children/adolescents with being overweight/having obesity is increasing, which has a certain impact on their psychology, such as depression and anxiety symptoms. Our purpose was to conduct a meta-analysis to assess the prevalence and odds ratios of depression and anxiety symptoms among overweight/obese children/adolescents and non-overweight/obese children/adolescents in China. As of July 2018, the three most comprehensive computerized academic databases in China have been systematically screened, namely China national knowledge infrastructure (CNKI) databases, Wanfang databases and Vip databases. The same operations are performed in PubMed and Web of Science (SCIE) databases without language restrictions. Case-control studies on prevalence of depression and anxiety symptoms in overweight/obese children/adolescents in China were analyzed. Study selection and evaluation were performed independently by three authors. Unweighted prevalence, pooled random-effects estimates of odds ratio (OR), and 95% confidence intervals (CI) were all calculated. A total of 11 eligible studies involving 17,894 subjects were included. The prevalence of depression and anxiety symptoms in overweight/obese children/adolescents was significantly higher than that in non-overweight/non-obese children/adolescents (depression: 21.73% vs. 17.96%, OR = 1.46, 95% CI: 1.14, 1.87, = 0.003; anxiety: 39.80% vs. 13.99%, OR = 1.47, 95% CI: 1.21, 1.79, < 0.001). Subgroup analyses conducted according to scale types showed that scale types have certain significance to evaluate the relationship between depression symptoms and overweight/obesity. The OR of depression symptoms between overweight/obese children/adolescents and non-overweight/non-obese children/adolescents was greatest on the Middle School Student Mental Health Scale (MSSMHS) was 2.06 (95% CI: 1.41, 3.02, I² = 0.00%), Center for Epidemiologic Studies Depression Scale (CES-D) was 1.03 (95% CI: 0.84, 1.25, I² = 0.00%), and Children's Depression Inventory (CDI) was 1.21 (95% CI: 1.02, 1.42, I² = 0.00%). We concluded that the prevalence of depression and anxiety symptoms in overweight/obese children/adolescents in China is higher than that in the non-overweight/obese children/adolescents. The results of the study indicate that the prevalence of depression and anxiety symptoms among overweight/obese children/adolescents in Chinese medical institutions should receive more attention. Physical exercise and psychological interventions should be strengthened to prevent psychological problems. However, because of some clear limitations (no clinical interview and few studies), these results should be interpreted with caution.
Topics: Adolescent; Anxiety; Asian People; Case-Control Studies; Child; China; Depression; Depressive Disorder; Exercise; Humans; Obesity; Odds Ratio; Overweight; Pediatric Obesity; Prevalence
PubMed: 30691096
DOI: 10.3390/ijerph16030340 -
Diabetes Research and Clinical Practice Aug 2023The effect of fecal microbiota transplantation (FMT) on microbiota engraftment in patients with metabolic syndrome remains unclear. This systematic review employed a... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
The effect of fecal microbiota transplantation (FMT) on microbiota engraftment in patients with metabolic syndrome remains unclear. This systematic review employed a meta-analysis of RCTs for assessment on the role of FMT in treating obesity and metabolic syndrome, and its impact on clinically relevant parameters.
METHOD
Major databases and grey literatures were searched identifying RCTs comparing FMT of lean donors with placebo in obese/metabolic syndrome patients. Studies using any form of placebo were included. Variations in the parameters before and after treatment were calculated followed by meta-analyses.
RESULT
Ten studies met the inclusion criteria and a total of 334 patients were included for further analysis. Clinically significant parameters associated with obesity and metabolic syndrome were explored and FMT was identified significantly and negatively associated with most indices of abdominal adiposity including caloric intake, fasting glucose, HOMA-IR, systolic blood pressure, diastolic blood pressure, total cholesterol, HDL, LDL, triglycerides and CRP, Obesity parameters including fasting glucose and acetic acid were increased following FMT.
CONCLUSION
FMT is more advantageous for obese patients with elevated blood pressure, disordered glucose and insulin metabolism, and elevated blood lipids. The study of metabolic factors in obese patients will be our starting point in the future.
Topics: Humans; Fecal Microbiota Transplantation; Metabolic Syndrome; Obesity; Glucose; Lipids
PubMed: 37356723
DOI: 10.1016/j.diabres.2023.110803 -
Diabetes/metabolism Research and Reviews Sep 2016Post-operative cognitive dysfunction, a condition distinct from post-operative delirium (POD), occurs frequently after surgery, and is related to dementia and premature... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Post-operative cognitive dysfunction, a condition distinct from post-operative delirium (POD), occurs frequently after surgery, and is related to dementia and premature death. Obesity increases the risk of late-life cognitive impairment, but little is known about its role in post-operative cognitive dysfunction. We conducted a systematic review and meta-analysis of studies on the association between obesity and risk of post-operative cognitive dysfunction.
METHODS
PubMed and the Cochrane Library were systematically searched. Studies were included if they had prospective designs, reported on human adults undergoing surgery, if cognitive function was measured pre- and post-surgery, if obesity, body mass index (BMI) and/or body weight were ascertained, and if associations with post-operative cognitive dysfunction were reported as relative risks or odds ratios. Underweight, weight loss, and post-operative delirium were not considered.
RESULTS
Inclusion criteria were met by six articles. Samples totaled 1432 older patients (mean age ≥62 years) who were followed up for 24 h to 12 months after surgery. Analysis of studies with obesity defined as a categorical measure found a non-significantly higher risk of post-operative cognitive dysfunction among persons with BMI > 30 kg/m(2) versus ≤30 kg/m(2) (relative risk 1.27; 95% confidence interval 0.95, 1.70; p = 0.10). No such associations were found for studies that analysed BMI or body weight continuously as predictors of post-operative cognitive dysfunction (relative risk 0.98 per kg/m(2) ; 95% confidence interval 0.93, 1.03, p = 0.45; relative risk 0.99 per kg; 95% confidence interval 0.89, 1.09; p = 0.83, respectively).
CONCLUSIONS
Few studies have addressed the topic, and the results of these studies provide only limited support for an increased risk of post-operative cognitive dysfunction in patients who are obese. Further large-scale, prospective investigations are necessary for clarification. Copyright © 2016 John Wiley & Sons, Ltd.
Topics: Cognitive Dysfunction; Humans; Obesity; Postoperative Complications; Prognosis
PubMed: 26890984
DOI: 10.1002/dmrr.2786 -
Journal of Alzheimer's Disease : JAD 2022Reduction in cerebral blood flow (CBF) plays an essential role in the cognitive impairment and dementia in obesity. However, current conclusions regarding CBF changes in... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Reduction in cerebral blood flow (CBF) plays an essential role in the cognitive impairment and dementia in obesity. However, current conclusions regarding CBF changes in patients with obesity are inconsistent.
OBJECTIVE
A systematic review and meta-analysis was performed to evaluate the relationship between obesity and CBF alterations.
METHODS
We systematically screened published cross-sectional and longitudinal studies focusing on the differences in CBF between obese and normal-weight individuals. Eighteen studies including 24,866 participants, of which seven articles reported longitudinal results, were evaluated in the present study.
RESULTS
The results of the meta-analysis showed that in cross-sectional studies, body mass index (BMI) was negatively associated with CBF (β= -0.31, 95% confidence interval [CI]: -0.44, -0.19). Moreover, this systematic review demonstrated that obese individuals showed global and regional reductions in the CBF and increased CBF in diverse functional areas of the frontal lobe, including the prefrontal cortex, left frontal superior orbital, right frontal mid-orbital cortex, and left premotor superior frontal gyrus.
CONCLUSION
Our findings suggest that BMI, rather than waist circumference and waist-to-hip ratio, is inversely associated with CBF in cross-sectional studies. The CBF of obese individuals showed global and regional reductions, including the frontal lobe, temporal and parietal lobes, cerebellum, hippocampus, and thalamus.
Topics: Humans; Cross-Sectional Studies; Cerebrovascular Circulation; Cognitive Dysfunction; Frontal Lobe; Obesity; Magnetic Resonance Imaging; Brain
PubMed: 36093706
DOI: 10.3233/JAD-220601