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Nutrients Dec 2020Recent observations have shown that lengthening the daily eating period may contribute to the onset of chronic diseases. Time-restricted eating (TRE) is a diet that...
INTRODUCTION
Recent observations have shown that lengthening the daily eating period may contribute to the onset of chronic diseases. Time-restricted eating (TRE) is a diet that especially limits this daily food window. It could represent a dietary approach that is likely to improve health markers. The aim of this study was to review how time-restricted eating affects human health.
METHOD
Five general databases and six nutrition journals were screened to identify all studies published between January 2014 and September 2020 evaluating the effects of TRE on human populations.
RESULTS
Among 494 articles collected, 23 were finally included for analysis. The overall adherence rate to TRE was 80%, with a 20% unintentional reduction in caloric intake. TRE induced an average weight loss of 3% and a loss of fat mass. This fat loss was also observed without any caloric restriction. Interestingly, TRE produced beneficial metabolic effects independently of weight loss, suggesting an intrinsic effect based on the realignment of feeding and the circadian clock.
CONCLUSIONS
TRE is a simple and well-tolerated diet that generates many beneficial health effects based on chrononutrition principles. More rigorous studies are needed, however, to confirm those effects, to understand their mechanisms and to assess their applicability to human health.
Topics: Caloric Restriction; Circadian Rhythm; Databases, Factual; Energy Intake; Fasting; Food; Health; Humans; Nutritional Status; Religion
PubMed: 33302500
DOI: 10.3390/nu12123770 -
European Heart Journal Jul 2023Due to growing environmental focus, plant-based diets are increasing steadily in popularity. Uncovering the effect on well-established risk factors for cardiovascular... (Meta-Analysis)
Meta-Analysis
AIMS
Due to growing environmental focus, plant-based diets are increasing steadily in popularity. Uncovering the effect on well-established risk factors for cardiovascular diseases, the leading cause of death worldwide, is thus highly relevant. Therefore, a systematic review and meta-analysis were conducted to estimate the effect of vegetarian and vegan diets on blood levels of total cholesterol, low-density lipoprotein cholesterol, triglycerides, and apolipoprotein B.
METHODS AND RESULTS
Studies published between 1980 and October 2022 were searched for using PubMed, Embase, and references of previous reviews. Included studies were randomized controlled trials that quantified the effect of vegetarian or vegan diets vs. an omnivorous diet on blood lipids and lipoprotein levels in adults over 18 years. Estimates were calculated using a random-effects model. Thirty trials were included in the study. Compared with the omnivorous group, the plant-based diets reduced total cholesterol, low-density lipoprotein cholesterol, and apolipoprotein B levels with mean differences of -0.34 mmol/L (95% confidence interval, -0.44, -0.23; P = 1 × 10-9), -0.30 mmol/L (-0.40, -0.19; P = 4 × 10-8), and -12.92 mg/dL (-22.63, -3.20; P = 0.01), respectively. The effect sizes were similar across age, continent, duration of study, health status, intervention diet, intervention program, and study design. No significant difference was observed for triglyceride levels.
CONCLUSION
Vegetarian and vegan diets were associated with reduced concentrations of total cholesterol, low-density lipoprotein cholesterol, and apolipoprotein B-effects that were consistent across various study and participant characteristics. Plant-based diets have the potential to lessen the atherosclerotic burden from atherogenic lipoproteins and thereby reduce the risk of cardiovascular disease.
Topics: Adult; Humans; Diet, Vegan; Diet, Vegetarian; Randomized Controlled Trials as Topic; Lipids; Vegetarians; Cholesterol, LDL; Lipoproteins; Cardiovascular Diseases; Atherosclerosis; Apolipoproteins
PubMed: 37226630
DOI: 10.1093/eurheartj/ehad211 -
Reproductive Sciences (Thousand Oaks,... Jan 2022A patients' increasing interest in dietary modifications as a possible complementary or alternative treatment of endometriosis is observed. Unfortunately, the...
A patients' increasing interest in dietary modifications as a possible complementary or alternative treatment of endometriosis is observed. Unfortunately, the therapeutic potential of dietary interventions is unclear and to date no guidelines to assist physicians on this topic exist. The aim of this study, therefore, was to systematically review the existing studies on the effect of dietary interventions on endometriosis. An electronic-based search was performed in MEDLINE and COCHRANE. We included human and animal studies that evaluated a dietary intervention on endometriosis-associated symptoms or other health outcomes. Studies were identified and coded using standard criteria, and the risk of bias was assessed with established tools relevant to the study design. We identified nine human and 12 animal studies. Out of the nine human studies, two were randomized controlled trials, two controlled studies, four uncontrolled before-after studies, and one qualitative study. All of them assessed a different dietary intervention, which could be classified in one of the following principle models: supplementation with selected dietary components, exclusion of selected dietary components, and complete diet modification. Most of the studies reported a positive effect on endometriosis; they were however characterized by moderate or high-risk bias possibly due to the challenges of conducting dietary intervention trials. According to the available level of evidence, we suggest an evidence-based clinical approach for physicians to use during consultations with their patients. Further well-designed randomized controlled trials are needed to accurately determine the short-term and long-term effectiveness and safety of different dietary interventions.
Topics: Diet; Endometriosis; Female; Humans; Randomized Controlled Trials as Topic
PubMed: 33761124
DOI: 10.1007/s43032-020-00418-w -
Nutrients Nov 2022Caloric restriction and vegan diets have demonstrated protective effects for diabetes, however their role in improving clinically relevant outcomes has not been... (Meta-Analysis)
Meta-Analysis Review
Investigating the Effectiveness of Very Low-Calorie Diets and Low-Fat Vegan Diets on Weight and Glycemic Markers in Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis.
Caloric restriction and vegan diets have demonstrated protective effects for diabetes, however their role in improving clinically relevant outcomes has not been summarized. Our aim was to evaluate the evidence for low-calorie diets (VLCD) and vegan diets on weight and glycemic control in the management of patients with Type 2 Diabetes. Database searches were conducted using Cochrane Library, MEDLINE (Ovid) and Embase. Systematic Review Registration: CRD42022310299. Methodological quality of studies was assessed using Cochrane RoB Tool for RCTs, Cochrane ROBINS-I RoB Tool for non-RCTs and NIH Quality Assessment tool for other studies. Sixteen studies with a total of 834 individuals were included and assessed to have a moderate to high risk of bias. Statistically significant changes in weight, BMI, and HbA1c were not observed in vegan diet cohorts. However, LDL cholesterol was significantly decreased by vegan diet. VLCDs significantly improved glycaemic control, with reductions in fasting glucose, pooled mean difference (MD) -1.51 mmol/L (95% CI -2.89, -0.13; = 0.03; 2 studies) and HbA1c, pooled MD -0.66% (95% CI -1.28, -0.03; = 0.04; 3 studies) compared to non-dietary therapy. Both diets suggested a trend towards improved weight loss and anthropometric markers vs. control. VLCD diet intervention is associated with improvement in glycaemia control in patients with Type 2 Diabetes.
Topics: Humans; Diet, Vegan; Diabetes Mellitus, Type 2; Glycated Hemoglobin; Caloric Restriction; Blood Glucose; Diet, Fat-Restricted; Biomarkers
PubMed: 36432557
DOI: 10.3390/nu14224870 -
International Journal of Environmental... Sep 2022(1) Background: Recently, studies have emerged to explore the effects of concurrent training (CT) with a low-carb, high-fat ketogenic diet (LCHF) on body composition and... (Meta-Analysis)
Meta-Analysis Review
The Effects of Concurrent Training Combined with Low-Carbohydrate High-Fat Ketogenic Diet on Body Composition and Aerobic Performance: A Systematic Review and Meta-Analysis.
(1) Background: Recently, studies have emerged to explore the effects of concurrent training (CT) with a low-carb, high-fat ketogenic diet (LCHF) on body composition and aerobic performance and observed its benefits. However, a large variance in the study design and observations is presented, which needs to be comprehensively assessed. We here thus completed a systematic review and meta-analysis to characterize the effects of the intervention combining CT and LCHF on body composition and aerobic capacity in people with training experience as compared to that combining CT and other dietary strategies. (2) Methods: A search strategy based on the PICOS principle was used to find literature in the databases of PubMed, Web of Science, EBSCO, Sport-discuss, and Medline. The quality and risk of bias in the studies were independently assessed by two researchers. (3) Result: Eight studies consisting of 170 participants were included in this work. The pooled results showed no significant effects of CT with LCHF on lean mass (SMD = -0.08, 95% CI -0.44 to 0.3, = 0.69), body fat percentage (SMD = -0.29, 95% CI -0.66 to 0.08, = 0.13), body mass (SMD = -0.21, 95% CI -0.53 to 0.11, = 0.2), VO (SMD = -0.01, 95% CI -0.4 to 0.37, = 0.95), and time (or distance) to complete the aerobic tests (SMD = -0.02, 95% CI -0.41 to 0.37, = 0.1). Subgroup analyses also showed that the training background of participants (i.e., recreationally trained participants or professionally trained participants) and intervention duration (e.g., > or ≤six weeks) did not significantly affect the results. (4) Conclusions: This systematic review and meta-analysis provide evidence that compared to other dietary strategies, using LCHF with CT cannot induce greater benefits for lean mass, body fat percentage, body mass, VO, and aerobic performance in trained participants.
Topics: Body Composition; Carbohydrates; Diet, High-Fat; Diet, Ketogenic; Exercise Tolerance; Humans
PubMed: 36141816
DOI: 10.3390/ijerph191811542 -
The International Journal of Behavioral... Aug 2017A wide range of interventions has been implemented and tested to prevent obesity in children. Given parents' influence and control over children's energy-balance... (Review)
Review
BACKGROUND
A wide range of interventions has been implemented and tested to prevent obesity in children. Given parents' influence and control over children's energy-balance behaviors, including diet, physical activity, media use, and sleep, family interventions are a key strategy in this effort. The objective of this study was to profile the field of recent family-based childhood obesity prevention interventions by employing systematic review and quantitative content analysis methods to identify gaps in the knowledge base.
METHODS
Using a comprehensive search strategy, we searched the PubMed, PsycIFO, and CINAHL databases to identify eligible interventions aimed at preventing childhood obesity with an active family component published between 2008 and 2015. Characteristics of study design, behavioral domains targeted, and sample demographics were extracted from eligible articles using a comprehensive codebook.
RESULTS
More than 90% of the 119 eligible interventions were based in the United States, Europe, or Australia. Most interventions targeted children 2-5 years of age (43%) or 6-10 years of age (35%), with few studies targeting the prenatal period (8%) or children 14-17 years of age (7%). The home (28%), primary health care (27%), and community (33%) were the most common intervention settings. Diet (90%) and physical activity (82%) were more frequently targeted in interventions than media use (55%) and sleep (20%). Only 16% of interventions targeted all four behavioral domains. In addition to studies in developing countries, racial minorities and non-traditional families were also underrepresented. Hispanic/Latino and families of low socioeconomic status were highly represented.
CONCLUSIONS
The limited number of interventions targeting diverse populations and obesity risk behaviors beyond diet and physical activity inhibit the development of comprehensive, tailored interventions. To ensure a broad evidence base, more interventions implemented in developing countries and targeting racial minorities, children at both ends of the age spectrum, and media and sleep behaviors would be beneficial. This study can help inform future decision-making around the design and funding of family-based interventions to prevent childhood obesity.
Topics: Adolescent; Australia; Child; Child, Preschool; Developing Countries; Diet; Energy Intake; Europe; Exercise; Family; Health Behavior; Humans; Minority Groups; Obesity; Pediatric Obesity; Research Design; Risk-Taking; United States
PubMed: 28836983
DOI: 10.1186/s12966-017-0571-2 -
Nutrients Feb 2022Limited consumption of dairy foods and use of low-fat products is recommended for cardiovascular (CV) prevention; however, other features besides fat content modulate... (Review)
Review
Limited consumption of dairy foods and use of low-fat products is recommended for cardiovascular (CV) prevention; however, other features besides fat content modulate their metabolic effects. We analyze updated evidence on the relationship of different dairy products (low/full-fat dairy, milk, cheese, yogurt) with CVD by reviewing meta-analyses of cohort studies and individual prospective cohort studies with CV hard endpoints (CVD/CHD incidence/mortality), together with meta-analyses of randomized controlled trials exploring the effect of dairy on major CV risk factors. The analyses provide evidence that moderate dairy consumption (up to 200 g/day, globally) has no detrimental effects on CV health and that their effect depends more on the food type (cheese, yogurt, milk) than on the fat content. These data expand current knowledge and may inform revision of current guidelines for CVD prevention.
Topics: Animals; Cardiovascular Diseases; Dairy Products; Diet; Diet, Fat-Restricted; Humans; Milk; Prospective Studies; Risk Factors
PubMed: 35215479
DOI: 10.3390/nu14040831 -
Annals of Medicine 2019Fibromyalgia (FM) is a chronic non-degenerative disease, whose nutritional therapy seems controversial. This systematic review aimed to synthesize the knowledge about...
Fibromyalgia (FM) is a chronic non-degenerative disease, whose nutritional therapy seems controversial. This systematic review aimed to synthesize the knowledge about the effect of dietary interventions on patient-reported outcomes (PRO) and inflammation in patients with FM. Six electronic databases - PubMed, BioMed Central, Cochrane library, EMBASE, LILACS and ISI - were searched for clinical trials, in which a dietary intervention in patients with FM diagnosed was conducted. Quality of evidence assessment was measured in accordance with GRADE methodology. Seven clinical trials - 3 randomized controlled trials, 1 unrandomized clinical trial and 3 uncontrolled clinical trials were identified. Dietary approaches included gluten-free diet ( = 1), raw vegetarian diet ( = 2), low Fermentable oligo-, di- and monossacharides, alcohols and polyols (FODMAPs) diet ( = 1), hypocaloric diet ( = 2) and monosodium glutamate- and aspartame-free diet interventions ( = 1). The major PRO were pain and functional repercussion, with 5 out of 7 studies reporting an improvement. The progress in secondary outcomes was reported for fatigue (2/5 studies), sleep quality (2/3 studies), depression and anxiety (3/6 studies), quality of life (4/5 studies), gastrointestinal symptoms (1/2 studies) and inflammatory biomarkers (1/1 study). However, according to Cochrane Risk of Bias, these studies had poor statistical quality. Well-designed studies should be performed to investigate the dietary interventions effect on FM. Key messages Fibromyalgia (FM) is a chronic non-degenerative disease, whose nutritional therapy seems controversial but promising. Pain and functional repercussion in FM patients seem to improve with a hypocaloric diet, a raw vegetarian diet or a low FODMAPs diet, as much as quality of life, quality of sleep, anxiety and depression and inflammatory biomarkers. Existing studies in this subject are scarce and low quality, which does not allow conclusions to be drawn.
Topics: Chronic Disease; Diet, Carbohydrate-Restricted; Diet, Gluten-Free; Diet, Reducing; Fibromyalgia; Humans; Quality of Life
PubMed: 30735059
DOI: 10.1080/07853890.2018.1564360 -
Nutrients Jan 2018Heart failure (HF) is a complex syndrome and is recognized as the ultimate pathway of cardiovascular disease (CVD). Studies using nutritional strategies based on dietary... (Review)
Review
BACKGROUND
Heart failure (HF) is a complex syndrome and is recognized as the ultimate pathway of cardiovascular disease (CVD). Studies using nutritional strategies based on dietary patterns have proved to be effective for the prevention and treatment of CVD. Although there are studies that support the protective effect of these diets, their effects on the prevention of HF are not clear yet.
METHODS
We searched the Medline, Embase, and Cochrane databases for studies that examined dietary patterns, such as dietary approaches to stop hypertension (DASH diet), paleolithic, vegetarian, low-carb and low-fat diets and prevention of HF. No limitations were used during the search in the databases.
RESULTS
A total of 1119 studies were identified, 14 met the inclusion criteria. Studies regarding the Mediterranean, DASH, vegetarian, and Paleolithic diets were found. The Mediterranean and DASH diets showed a protective effect on the incidence of HF and/or worsening of cardiac function parameters, with a significant difference in relation to patients who did not adhere to these dietary patterns.
CONCLUSIONS
It is observed that the adoption of Mediterranean or DASH-type dietary patterns may contribute to the prevention of HF, but these results need to be analyzed with caution due to the low quality of evidence.
Topics: Adult; Aged; Aged, 80 and over; Diet, Healthy; Diet, Mediterranean; Diet, Paleolithic; Diet, Vegetarian; Dietary Approaches To Stop Hypertension; Feeding Behavior; Female; Heart Failure; Humans; Incidence; Male; Middle Aged; Nutritional Status; Nutritive Value; Primary Prevention; Protective Factors; Recommended Dietary Allowances; Risk Factors; Risk Reduction Behavior; Treatment Outcome
PubMed: 29320401
DOI: 10.3390/nu10010058 -
The Cochrane Database of Systematic... Jun 2020Ketogenic diets (KDs) are high in fat and low in carbohydrates and have been suggested to reduce seizure frequency in people with epilepsy. Such diets may be beneficial... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Ketogenic diets (KDs) are high in fat and low in carbohydrates and have been suggested to reduce seizure frequency in people with epilepsy. Such diets may be beneficial for children with drug-resistant epilepsy. This is an update of a review first published in 2003, and last updated in 2018.
OBJECTIVES
To assess the effects of ketogenic diets for people with drug-resistant epilepsy.
SEARCH METHODS
For this update, we searched the Cochrane Register of Studies (CRS Web) and MEDLINE (Ovid, 1946 to 26 April 2019) on 29 April 2019. The Cochrane Register of Studies includes the Cochrane Epilepsy Group Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL), and randomised controlled trials (RCTs) from Embase, ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We imposed no language restrictions. We checked the reference lists of retrieved studies for additional relevant studies.
SELECTION CRITERIA
RCTs or quasi-RCTs of KDs for people of any age with drug-resistant epilepsy.
DATA COLLECTION AND ANALYSIS
Two review authors independently applied predefined criteria to extract data and evaluated study quality. We assessed the outcomes: seizure freedom, seizure reduction (50% or greater reduction in seizure frequency), adverse effects, cognition and behaviour, quality of life, and attrition rate. We incorporated a meta-analysis. We utilised an intention-to-treat (ITT) population for all primary analyses. We presented the results as risk ratios (RRs) with 95% confidence intervals (CIs).
MAIN RESULTS
We identified 13 studies with 932 participants; 711 children (4 months to 18 years) and 221 adults (16 years and over). We assessed all 13 studies to be at high risk of performance and detection bias, due to lack of blinding. Assessments varied from low to high risk of bias for all other domains. We rated the evidence for all outcomes as low to very low certainty. Ketogenic diets versus usual care for children Seizure freedom (RR 3.16, 95% CI 1.20 to 8.35; P = 0.02; 4 studies, 385 participants; very low-certainty evidence) and seizure reduction (RR 5.80, 95% CI 3.48 to 9.65; P < 0.001; 4 studies, 385 participants; low-certainty evidence) favoured KDs (including: classic KD, medium-chain triglyceride (MCT) KD combined, MCT KD only, simplified modified Atkins diet (MAD) compared to usual care for children. We are not confident that these estimated effects are accurate. The most commonly reported adverse effects were vomiting, constipation and diarrhoea for both the intervention and usual care group, but the true effect could be substantially different (low-certainty evidence). Ketogenic diet versus usual care for adults In adults, no participants experienced seizure freedom. Seizure reduction favoured KDs (MAD only) over usual care but, again, we are not confident that the effect estimated is accurate (RR 5.03, 95% CI 0.26 to 97.68; P = 0.29; 2 studies, 141 participants; very low-certainty evidence). Adults receiving MAD most commonly reported vomiting, constipation and diarrhoea (very low-certainty evidence). One study reported a reduction in body mass index (BMI) plus increased cholesterol in the MAD group. The other reported weight loss. The true effect could be substantially different to that reported. Ketogenic diet versus ketogenic diet for children Up to 55% of children achieved seizure freedom with a classical 4:1 KD after three months whilst up to 85% of children achieved seizure reduction (very low-certainty evidence). One trial reported a greater incidence of seizure reduction with gradual-onset KD, as opposed to fasting-onset KD. Up to 25% of children were seizure free with MAD and up to 60% achieved seizure reduction. Up to 25% of children became seizure free with MAD and up to 60% experienced seizure reduction. One study used a simplified MAD (sMAD) and reported that 15% of children gained seizure freedom rates and 56% achieved seizure reduction. We judged all the evidence described as very low certainty, thus we are very unsure whether the results are accurate. The most commonly reported adverse effects were vomiting, constipation and diarrhoea (5 studies, very low-certainty evidence). Two studies reported weight loss. One stated that weight loss and gastrointestinal disturbances were more frequent, with 4:1 versus 3:1 KD, whilst one reported no difference in weight loss with 20 mg/d versus 10 mg/d carbohydrates. In one study, there was a higher incidence of hypercalcuria amongst children receiving classic KD compared to MAD. All effects described are unlikely to be accurate. Ketogenic diet versus ketogenic diet for adults One study randomised 80 adults (aged 18 years and over) to either MAD plus KetoCal during the first month with MAD alone for the second month, or MAD alone for the first month followed by MAD plus KetoCal for the second month. No adults achieved seizure freedom. More adults achieved seizure reduction at one month with MAD alone (42.5%) compared to MAD plus KetoCal (32.5%), however, by three months only 10% of adults in both groups maintained seizure reduction. The evidence for both outcomes was of very low certainty; we are very uncertain whether the effects are accurate. Constipation was more frequently reported in the MAD plus KetoCal group (17.5%) compared to the MAD only group (5%) (1 study, very low-certainty evidence). Diarrhoea and increase/change in seizure pattern/semiology were also commonly reported (17.5% to 20% of participants). The true effects of the diets could be substantially different to that reported.
AUTHORS' CONCLUSIONS
The evidence suggests that KDs could demonstrate effectiveness in children with drug-resistant epilepsy, however, the evidence for the use of KDs in adults remains uncertain. We identified a limited number of studies which all had small sample sizes. Due to the associated risk of bias and imprecision caused by small study populations, the evidence for the use of KDs was of low to very low certainty. More palatable but related diets, such as the MAD, may have a similar effect on seizure control as the classical KD, but could be associated with fewer adverse effects. This assumption requires more investigation. For people who have drug-resistant epilepsy or who are unsuitable for surgical intervention, KDs remain a valid option. Further research is required, particularly for adults with drug-resistant epilepsy.
Topics: Adolescent; Adult; Age Factors; Aged; Child; Child, Preschool; Diet, Carbohydrate-Restricted; Diet, High-Protein Low-Carbohydrate; Diet, Ketogenic; Dietary Carbohydrates; Dietary Fats; Drug Resistant Epilepsy; Humans; Infant; Intention to Treat Analysis; Middle Aged; Prospective Studies; Quality of Life; Randomized Controlled Trials as Topic; Retrospective Studies; Sample Size; Young Adult
PubMed: 32588435
DOI: 10.1002/14651858.CD001903.pub5