Nutrition and health

Objectives:
There are numerous trials reported the effect of alpha-lipoic acid (ALA) on obesity measurements; while no summarised dose-response meta-analysis is available to address the effects of dose and duration of ALA supplementation on obesity measurements. Therefore, this review article has been conducted.

Does alpha-lipoic acid supplementation improve obesity measurements including weight, body mass index (BMI), waist circumference (WC), waist to hip ratio (WHR) and fat mass (FM)?

Study design:
This review article included 18, 21 and 8 RCTs of ALA-weight, ALA-BMI, ALA-WC, respectively.

Results and conclusions:
The investigators found in two-class meta-analysis, alpha-lipoic acid supplementation significantly reduced weight [WMD = -2.29 kg, 95% CI = -2.98 to -1.60, p 0.01] and BMI [WMD = -0.49 g/m², 95% CI = -0.83 to -0.15, p = 0.005] but had no effect on waist circumference [WMD = -2.57 cm, 95% CI = -8.91 to 3.76, p = 0.426].

The investigators found while the dose-response meta-analysis revealed that the duration of alpha-lipoic acid supplementation was a significant factor affecting waist circumference reduction [p non-linearity = 0.047].
While no evidence of departure from linearity was observed for other variables; moreover, subgrouping also revealed that gender could be an important factor affecting the alpha-lipoic acid impact on waist circumference, which was significant among women [WMD = -4.099, 95%CI = -7.837 to -0.361, p = 0.032].

The investigators concluded that alpha-lipoic acid supplementation reduces BMI, weight in a two-class meta-analysis without evidence of departure from linearity in terms of dose or duration. While the association of alpha-lipoic acid supplementation on waist circumference is dependent to the duration of the study. Although further trials evaluating the other obesity measurements specially central obesity will be helpful to infer a more reliable result.

Original title:
Alpha-lipoic acid supplementation significantly reduces the risk of obesity in an updated systematic review and dose response meta-analysis of randomised placebo-controlled clinical trials by Vajdi M and Farhangi MA.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/32091656

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Objectives:
Nitric oxide related ergogenic aids such as arginine (Arg) have shown to impact positively on sport performance through several physiological and metabolic mechanisms. However, research results have shown to be controversial. Therefore, this review article has been conducted.

Do both acute and chronic arginine supplementation increase aerobic (≤VO2max) and anaerobic (>VO2max) performance?

Study design:
This review article included 15 RCTs with 386 males and 8 females.

Arginine supplementation was ingested by participants in both acute and chronic protocols.
Acute arginine protocol was 0.15 g/kg (≈10-11 g) ingested between 60-90 minutes before physical exercises.

Chronic arginine protocol was 1.5-2 g/day during 4-7 weeks or 10-12 g/day during 8 weeks.

Random effects model and pooled standardized mean differences (SMD) were used according to Hedges’ g.

Egger’s analyses did not find publication bias in anaerobic performance [z = 0.786, p = 0.432]. However, funnel plot showed publication bias in aerobic performance data [z = 2.873, p 0.05].

Results and conclusions:
The investigators found both acute and chronic arginine supplementation significantly improved anaerobic performance [SMD = 0.24, 95% CI = 0.05 to 0.43, p = 0.01, I2 = 0%, p = 0.85].

The investigators found both acute and chronic arginine supplementation significantly improved aerobic performance [SMD = 0.84, 95% CI = 0.12 to 1.56, p = 0.02, I2 = 89%, p 0.001].

The investigators concluded both acute and chronic arginine supplementation improve (anaerobic/aerobic) performance.

Original title:
Effects of Arginine Supplementation on Athletic Performance Based on Energy Metabolism: A Systematic Review and Meta-Analysis by Viribay A, Burgos J, […], Mielgo-Ayuso J.

Link:
https://www.mdpi.com/2072-6643/12/5/1300/htm

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Find here more information/studies about arginine and sport nutrition.

Objectives:
Does coenzyme Q10 supplementation reduce body weight and body mass index (BMI) of patients in randomized controlled clinical trial studies (RCTs)?

Study design:
This review article included 17 RCTs.

Results and conclusions:
The investigators found results of random-effect size meta-analysis showed that supplementation with coenzyme Q10 had no significant decreasing effects on body weight [WMD = 0.28 kg, 95% CI = -0.91 to 1.47, p = 0.64] and BMI [WMD = -0.03, 95% CI = -0.4 to 0.34, p = 0.86] of study participants.
No significant because the calculated p-value of 0.64 was larger than the p-value of 0.05.
Subgroup analysis revealed that dosage of Q10 and trial duration could not differ the results of Q10 supplementation.

The investigators concluded that coenzyme Q10 supplementation has no decreasing effects on body weight and BMI.

Original title:
Effect of Q10 supplementation on body weight and body mass index: A systematic review and meta-analysis of randomized controlled clinical trials by Saboori S, Rad EY, […], Falahi E.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31336462

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Objectives:
Does protein supplementation yield beneficial effects on body composition and muscle function (strength and synthesis) in healthy adults, with an emphasis on the timing of protein intake?

Study design:
This review article included 65 RCTs with 2,907 participants (1,514 men and 1,380 women, 13 unknown sex). 26, 8 and 24 studies were used for meta-analysis on lean body mass, handgrip strength and leg press strength, respectively.

Results and conclusions:
The investigators found protein supplementation was effective in improving lean body mass (LBM) in adults [MD = 0.62 kg, 95% CI = 0.36 to 0.88] and older adults [MD = 0.46 kg, 95% CI = 0.23 to 0.70].
Sensitivity analyses removing studies without exercise training had no impact on the outcome.

The investigators found no association between protein supplementation and handgrip strength [older adults: MD = 0.26 kg, 95% CI = -0.51 to 1.04] and leg press strength [adults: MD = 5.80 kg, 95% CI = -0.33 to 11.93 and older adults: MD = 1.97 kg, 95% CI = -2.78 to 6.72].
Sensitivity analyses removing studies without exercise training had no impact on the outcome.

The investigators found data regarding muscle synthesis were scarce and inconclusive.

The investigators found subgroup analyses showed no beneficial effect of a specific timing of protein intake on lean body mass, handgrip strength and leg press strength.

The investigators concluded there is a positive impact of protein supplementation on lean body mass of healthy adults and older adults, independently of intake timing.

Original title:
The Role of Protein Intake and its Timing on Body Composition and Muscle Function in Healthy Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials by Wirth J, Hillesheim E and Brennan L.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/32232404

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The more lean body mass a person has, the higher their resting metabolic rate. Resting metabolic rate is the total number of calories burned when your body is completely at rest. Resting metabolic rate supports breathing, circulating blood, organ functions and basic neurological functions.

Objectives:
Results regarding the association between fish intake and risk of metabolic syndrome (MetS) are ambiguous. Therefore, this review article has been conducted.

Does fish consumption reduce risk of metabolic syndrome?

Study design:
This review article included 10 cross-sectional studies and 6 cohort studies.

Results and conclusions:
The investigators found fish consumption significantly reduced risk of metabolic syndrome with 20% [OR = 0.80, 95% CI = 0.66 to 0.96, p = 0.017, I2 = 62.9%] in cohort studies.
However, this reduced risk was not significant in cross-sectional studies [OR = 0.80, 95% CI = 0.70 to 1.02, p = 0.085, I2 = 50.1%].
Significantly because OR of 1 was not found in the 95% CI of 0.6 to 0.96. OR of 1 means no risk/association.

The investigators found a significant non-linear association between fish intake levels and risk of metabolic syndrome [p for non-linearity = 0.010].

The investigators concluded that fish consumption reduces risk of metabolic syndrome when combining data from prospective cohort studies. Further studies are needed to confirm such an effect.

Original title:
A systematic review and meta-analysis of the association between fish consumption and risk of metabolic syndrome by Karimi G, Heidari Z, [...], Haghighatdoost F.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/32127332

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Objectives:
Which types of exercise training (whole body vibration training, aerobic training, strength training and combined training) increase lumbar spine and femoral neck bone mineral density (BMD) in older postmenopausal women (PMW)?

Study design:
This review article included 16 RCTs with 1,624 subjects.

Results and conclusions:
The investigators found no significant change in lumbar spine bone mineral density following exercise training [MD = 0.01 g/cm², 95% CI = -0.01 to 0.02].

The investigators found no significant change in femoral neck bone mineral density following exercise training [MD = 0.00 g/cm², 95% CI = -0.01 to 0.01].

The investigators found, however, subgroup analysis by type of exercise training revealed that lumbar spine bone mineral density [MD = 0.01, 95% CI = 0.00 to 0.02] raised significantly when whole-body vibration (WBV) was employed as intervention compared with RCTs that utilized aerobic [MD = -0.01, 95% CI = -0.02 to -0.01], resistance [MD = 0.01, 95% CI = -0.04 to 0.06] or combined training [MD = 0.03, 95% CI = -0.01 to 0.08].

The investigators found, on the other hand, lumbar spine bone mineral density [MD = - 0.01, 95% CI = -0.02 to -0.01] reduced significantly when aerobic exercise training was used as intervention compared with RCTs that utilized resistance training, combined training or whole-body vibration. 

The investigators concluded whole-body vibration is an effective method to improve lumbar spine bone mineral density in older postmenopausal women.

Original title:
The Impact of Different Modes of Exercise Training on Bone Mineral Density in Older Postmenopausal Women: A Systematic Review and Meta-analysis Research by Mohammad Rahimi GR, Smart NA, […], Mohammad Rahimi N.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/32055889

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Objectives:
Genistein (4',5,7-trihydroxyisoflavone) is a phytoestrogen with potential health benefits in the prevention of cardiovascular disease. However, the evidence regarding its effects on hypertension has not been conclusive. Therefore, this review article has been conducted.

Do genistein supplements reduce blood pressure?

Study design:
This review article included 4 RCTs (4 treatment arms).

Results and conclusions:
The investigators found genistein supplements did not show any significant reduction of systolic blood pressure [WMD = -5.32 mmHg, 95% CI = -14.59 to 3.96] and diastolic blood pressure [WMD = -2.06 mmHg, 95% CI = -6.41 to 2.28] compared to that of the placebo group.

The investigators found, however, subgroup analysis by intervention duration showed that more than 6 months genistein supplementation in metabolic syndrome patients significantly decreased systolic blood pressure [WMD = -13.73 mmHg, 95% CI = -18.10 to -9.37] and diastolic blood pressure [WMD = -5.18 mmHg, 95% CI = -6.62 to -3.74].

The investigators concluded genistein supplementation of more than 6 months reduces blood pressure among metabolic syndrome patients.

Original title:
Effects of genistein on blood pressure: A systematic review and meta-analysis by Hemati N, Asis M, […], Abdollahi M.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31955737

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Objectives:
The relationship between serum copper (Cu) level and overweight/obesity remains controversial. Therefore, this review article (meta-analysis) has been conducted.

Does a high serum copper level increase overweight/obesity risk?

Study design:
This review article included 21 articles.

Results and conclusions:
The investigators found compared with controls, serum copper level was significantly higher in obese children [SMD = 0.74, 95% CI = 0.16 to 1.32] and in obese adults [SMD = 0.39, 95% CI = 0.02 to 0.76].

The investigators found no significant difference in serum copper level between overweight and control groups in children [SMD = 1.52, 95% CI = -0.07 to 3.12] and in adults [SMD = 0.16, 95% CI = -0.06 to 0.38].

The investigators found subgroup analysis revealed a higher serum copper level in obese children [SMD = 0.90, 95% CI = 0.36 to 1.45] and obese adults [SMD = 0.47, 95% CI = 0.05 to 0.88] compared with healthy weight controls.

The investigators found the SMD differed significantly between obese children diagnosed by weight-for-height and controls [SMD = 1.56, 95% CI = 0.57 to 2.55] and there was a significant difference of serum copper level between obese adults diagnosed by BMI (WHO) and controls [SMD = 0.54, 95% CI = 0.08 to 1.01].

The investigators concluded that a higher serum copper level increases risk of obesity in children and adults and these findings need to be further confirmed.

Original title:
The Relationship Between Serum Copper and Overweight/Obesity: a Meta-analysis by Gu K, Li X, […], Jiang X.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31300957

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Objectives:
Does strength training improve total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), C-reactive protein (CRP) and adiponectin levels of adults?

Study design:
This review article included clinical trials up to May 2017.

Results and conclusions:
The investigators found strength training significantly reduced total cholesterol levels [ES = -0.399, p  0.001]. 

The investigators found strength training significantly reduced triglycerides levels [ES = -0.204, p = 0.002]. 

The investigators found strength training significantly reduced LDL cholesterol levels [ES = -0.451, p  0.001]. 

The investigators found strength training significantly reduced CRP levels [ES = -0.542, p = 0.01]. 

The investigators found strength training significantly increased HDL cholesterol levels [ES = 0.363, p  0.001]. 

The investigators found strength training significantly increased adiponectin levels [ES = 1.105, p = 0.01]. 

The investigators concluded strength training promotes decreases in total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL) (also called bad cholesterol), C-reactive protein (CRP) levels and increases high-density lipoprotein (HDL) (also called good cholesterol) and adiponectin levels of adults. Thus, progressive strength training could be a potential therapeutic option for improving abnormalities in lipid and inflammatory outcomes in adults.

Original title:
Effect of Strength Training on Lipid and Inflammatory Outcomes: Systematic Review With Meta-Analysis and Meta-Regression by Costa RR, Buttelli ACK, […], Kruel LFM.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31023184

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Find here more information/studies cholesterol and sport nutrition.

Objectives:
Does consumption of fruit or vegetables reduce risk of metabolic syndrome (MetS)?

Study design:
This review article included 9 observational studies (7 cross-sectional studies and 2 cohort studies).

Results and conclusions:
The investigators found in a dose-response analysis of 2 cohort studies and 7 cross-sectional studies, that an increase of 100 g/d in fruit consumption significantly reduced risk of metabolic syndrome with 3% [OR = 0.97, 95% CI = 0.95 to 0.99, I2 = 26.7%], whereas an increase of 100 g/d in vegetable consumption (9 studies) was not associated with a reduction in the metabolic syndrome [OR = 0.98, 95% CI = 0.96 to 1.01, I2 = 54.6%].

The investigators concluded 100 g/d fruit consumption reduces risk of metabolic syndrome. However, prospective studies or randomised clinical trials are needed to identify the effects of fruits by variety on the risk of the metabolic syndrome.

Original title:
Fruit and vegetable consumption and the metabolic syndrome: a systematic review and dose-response meta-analysis by Lee M, Lim M and Kim J.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31514758

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Objectives:
Creatine supplements are intended to improve performance, but there are indications that it can overwhelm liver and kidney functions, reduce the quality of life and increase mortality. Therefore, this review article has been conducted.

Does creatine supplementation increase risk of renal damage?

Study design:
This review article included 15 studies in the qualitative analysis and 6 studies in the quantitative analysis.

Results and conclusions:
The investigators found creatine supplementation did not significantly increase serum creatinine levels [standardized mean difference = 0.48, 95% CI = 0.24-0.73, p = 0.001, I2 = 22%].

The investigators found creatine supplementation did not significantly increase plasma urea values [standardized mean difference = 1.10, 95% CI = 0.34-1.85, p = 0.004, I2 = 28%].
The investigators concluded that creatine supplementation does not induce renal damage in the studied amounts and durations.

Original title:
Effects of Creatine Supplementation on Renal Function: A Systematic Review and Meta-Analysis by de Souza ESA, Pertille A, […], de Oliveira JJ.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31375416

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Find here more information/studies on kidney disease and creatine.

Objectives:
The lipid distribution in people who are overweight and obese is directly related to metabolic diseases. Quercetin supplementation may be an appropriate approach for reducing the risk factors of metabolic diseases in people who are obese. Therefore, this review article has been conducted.

Does quercetin supplementation reduce risk factors of metabolic diseases in people who are obese?

Study design:
This review article included 5 RCTs.

Results and conclusions:
The investigators found ≥150 mg/day quercetin supplementation during >6 weeks significantly reduced LDL-cholesterol (bad cholesterol) levels in people who are obese [SMD = -0.8, 95% CI = -1.21 to -0.39, p 0.00001].

The investigators concluded ≥150 mg/day quercetin supplementation during >6 weeks reduces LDL-cholesterol levels in people who are obese.

Original title:
Quercetin Actions on Lipid Profiles in Overweight and Obese Individuals: A Systematic Review and Meta-analysis by Guo W, Gong X and Li M.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31465275

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Objectives:
L-carnitine plays a fundamental biological role in the metabolism of lipids and may positively affect blood pressure by decreasing insulin resistance, although the latter remains less clear. Therefore, this review article has been conducted.

Does L-carnitine supplementation reduce blood pressure?

Study design:
This review article included 10 RCTs using a random-effects model to estimate the pooled effect sizes of L-carnitine supplementation on systolic (SBP) and diastolic blood pressure (DBP).

Results were expressed as weighted mean difference (WMD) and 95% confidence intervals (CI).

No evidence of publication bias was observed about the effects of L-carnitine supplementation on systolic blood pressure [p = 0.307] and diastolic blood pressure [p = 0.729], as evidenced by the results of the Egger's test.

Results and conclusions:
The investigators found L-carnitine supplementation decreased diastolic blood pressure [WMD = -1.162 mmHg, 95% CI = -2.020 to -0.303, p = 0.008] without changing systolic blood pressure levels [WMD = -0.085 mmHg, 95% CI = -1.455 to 1.285, p = 0.903].

The investigators found results of subgroup analyses revealed L-carnitine supplementation decreased diastolic blood pressure levels in participants with overweight and obesity [WMD = -1.232 mmHg, 95% CI = -2.297 to -0.167, p = 0.023] and with doses of 2 g/d [WMD = -1.639 mmHg, 95% CI = -3.038 to -0.240, p = 0.022].

The investigators concluded that 2 g/d L-carnitine supplementation decreases diastolic blood pressure in participants with overweight and obesity. However, more research is required to determine the molecular mechanism underlying the relationship between of L-carnitine on blood pressure.

Original title:
Effects of L-carnitine supplementation on blood pressure: a systematic review and meta-analysis of randomized controlled trials by Askarpour M, Hadi A, […], Ghaedi E.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31481697

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Objectives:
Epidemiological investigations evaluating the association of dietary calcium intake with metabolic syndrome (MetS) risk have yielded controversial results. Therefore, this review article has been conducted.

Does dietary calcium intake reduce risk of metabolic syndrome?

Study design:
This review article included a total 15 cross-sectional studies for dietary calcium intake.

Results and conclusions:
The investigators found for the highest versus lowest category of dietary calcium intake, a significantly reduced risk of 20% [combined OR = 0.80, 95% CI = 0.70 to 0.91] for metabolic syndrome.

The investigators found in dose-response analysis, a non-linear relationship between dietary intake of calcium and risk of metabolic syndrome [p non-linearity > 0.001].

The investigators found 280 mg/d dietary calcium intake significantly reduced risk of metabolic syndrome with 13% [OR = 0.87, 95% CI = 0.82 to 0.93].

The investigators concluded 280 mg/d dietary calcium intake may reduce risk of metabolic syndrome. May reduce because this review article only included cross-sectional studies and no cohort studies. Therefore, these findings should need to be further confirmed by larger prospective cohort studies.

Original title:
Dietary calcium intake and the risk of metabolic syndrome: evidence from observational studies by Cheng L, Hu D and Jiang W.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30846011

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Objectives:
Is there a relationship between the intake of foods (whole grains, refined grains, vegetables, fruit, nuts, legumes, eggs, dairy, fish, red meat, processed meat and sugar-sweetened beverages) and risk of general overweight/obesity, abdominal obesity and weight gain?

Study design:
This review article included 25 prospective cohort studies until August 2018.
In detail, 6 prospective cohort studies were included in the meta-analysis for consumption of whole grains, 4 studies for refined grains, 7 for vegetables, 6 for fruit, 4 for nuts, 2 for legumes, 2 for eggs, 11 for dairy products, 4 for fish, 4 for red meat, 2 for processed meat and 9 for sugar-sweetened beverages.

Results and conclusions:
The investigators found in the dose-response meta-analysis a significantly reduced risk of 7% per each increase of 30g/d whole-grain products [RR overweight/obesity = 0.93, 95% CI = 0.89 to 0.96, I2 = 0%].
There was no indication for a nonlinear association between whole-grain intake and risk of overweight/obesity [p-nonlinearity = 0.16].

The investigators found in the dose-response meta-analysis a significantly reduced risk of 7-9% per each increase of 100g/d fruit consumption [RR overweight/obesity = 0.93, 95% CI = 0.86 to 1.00, I2 = 89% and RR weight gain = 0.91, 95% CI = 0.86 to 0.97, I2 =7%].
There was no indication of a nonlinear relation [p-nonlinearity = 0.17, p-nonlinearity = 0.14, respectively].

The investigators found in the dose-response meta-analysis a significantly reduced risk of 58% per each increase of 28g/d nut consumption [RR abdominal obesity = 0.42, 95% CI = 0.31 to 0.57].

The investigators found in the dose-response meta-analysis a significantly reduced risk of 12% per each increase of 50g/d legume consumption [RR overweight/obesity = 0.88, 95% CI = 0.84 to 0.93].

The investigators found in the dose-response meta-analysis a significantly reduced risk of 17% per each increase of 100g/d fish consumption [RR abdominal obesity = 0.83, 95% CI = 0.71 to 0.97, I2 = 0%].
There was no indication of nonlinearity [p-nonlinearity = 0.07], but the graph indicated a stronger risk reduction at lower levels of fish intake and the curve reached a plateau at ∼40 g/d.

The investigators found in the dose-response meta-analysis a significantly increased risk of 5% per each increase of 30g/d refined grains consumption [RR overweight/obesity = 1.05, 95% CI = 1.00 to 1.10, I2 = 61%].
However, the nonlinear dose-response meta-analysis indicated that the association had a J-shape curve and a higher risk of overweight/obesity was identified for an intake of refined grains >90 g/d [p-nonlinearity 0.001].

The investigators found in the dose-response meta-analysis a significantly increased risk of 10-14% per each increase of 30g/d red meat consumption [RR abdominal obesity = 1.10, 95% CI = 1.04 to 1.16, I2 = 0% and RR weight gain = 1.14, 95% CI = 1.03 to 1.26].

The investigators found in the dose-response meta-analysis a significantly increased risk of 5-12% with each increase of 250 mL sugar-sweetened beverages per day consumption [RR overweight/obesity = 1.05, 95% CI = 1.00 to 1.11 and RR abdominal obesity = 1.12, 95% CI = 1.04 to 1.20, I2 = 38%].  
The increase in risk was stronger at lower amounts of sugar-sweetened beverages intake (until ∼300 mL/d), but an increase at higher intakes was still present [p-nonlinearity = 0.03].

The investigators found the intake of 5 servings of whole grains/d, 3 servings of vegetables/d and 3 servings of fruit/d significantly resulted in a 38% reduction in risk of overweight/obesity compared with non-consumption of these food groups.

The investigators found the intake of 5 servings of refined grains/d and 3 servings of sugar-sweetened beverages/d significantly resulted in a 59% increased risk of overweight/obesity.

The investigators concluded that high intakes of whole grains, vegetables, fruit and probably fish as well as a low intake of refined grains, red meat and sugar-sweetened beverages are associated with a reduced risk of measures of adiposity, including overweight/obesity, abdominal obesity or weight gain, respectively. These findings are in line with current public health recommendations regarding a health-promoting diet. However, with the current evidence rated as very low to low, findings should be interpreted with caution and better-designed observational studies, more evidence from intervention trials and use of novel statistical methods (e.g., substitution analyses or network meta-analyses) are needed.

Original title:
Food Groups and Risk of Overweight, Obesity, and Weight Gain: A Systematic Review and Dose-Response Meta-Analysis of Prospective Studies by Schlesinger S, Neuenschwander M, […], Schwingshackl BH.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6416048/

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Objectives:
Studies have shown that creatine supplementation increases intramuscular creatine concentrations, favoring the energy system of phosphagens, which may help explain the observed improvements in high-intensity exercise performance. However, research on physical performance in soccer has shown controversial results, in part because the energy system used is not taken into account. Therefore, this review article (meta-analysis) has been conducted.

Does creatine supplementation improve physical performance in soccer players?

Study design:
This review article included 9 RCTs with a total sample of 168 soccer players (118 males, 50 females) with an average age of 20.3 ± 2.0 years (from 15 to 30 years, as an average for the experimental sample).

The meta-analysis was performed using the random effects model and pooled standardized mean differences (SMD) (Hedges's g).

Results and conclusions:
The investigators found that creatine supplementation did not present beneficial effects on aerobic performance tests [SMD = -0.05, 95% CI = -0.37 to 0.28, p = 0.78] and phosphagen metabolism performance tests (strength, single jump, single sprint and agility tests: SMD = 0.21, 95% CI = -0.03 to 0.45, p = 0.08].

The investigators found, however, creatine supplementation showed beneficial effects on anaerobic performance tests [SMD = 1.23, 95% CI = 0.55 to 1.91, p 0.001].
Concretely, creatine supplementation demonstrated a large and significant effect on Wingate test performance [SMD = 2.26, 95% CI = 1.40 to 3.11, p 0.001].

The investigators concluded creatine supplementation with a loading dose of 20-30 g/day, divided 3-4 times per day, ingested for 6 to 7 days and followed by 5 g/day for 9 weeks or with a low dose of 3 mg/kg/day for 14 days presents positive effects on improving physical performance tests related to anaerobic metabolism, especially anaerobic power, in soccer players.

Original title:
Effects of Creatine Supplementation on Athletic Performance in Soccer Players: A Systematic Review and Meta-Analysis by Mielgo-Ayuso J, Calleja-Gonzalez J, […], Fernández-Lázaro D.

Link:
https://www.mdpi.com/2072-6643/11/4/757/htm

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Find here more information/studies about sport nutrition and creatine.

Objectives:
Epidemiological evidences regarding the association between physical activity and the risk of lung cancer are still controversial. Therefore, this review article has been conducted.

Does physical activity reduce risk of lung cancer?

Study design:
This review article included 20 cohort studies with a total of 2,965,811 participants and 31,807 lung cancer cases.

The study population were adults with age of >18 years.
Most studies were adjusted for major confounders including age, sex, smoking status and body mass index, etc.

The quality scores ranged from 5 to 9 with a median score of 8.
3 studies were evaluated with a score of 7 and others with a score of ≥7. Thus, the majority of the studies included in the meta-analysis were assessed as high-quality studies.

There might be little indication of publication bias in this meta-analysis.

Results and conclusions:
The investigators found compared with the low level of physical activity, the high level of physical activity significantly reduced risk of lung cancer with 17% [pooled RR = 0.83, 95% CI = 0.77 to 0.90, I2 = 62.6%, p heterogeneity 0.001].

The investigators found in subgroup analyses, compared with the low level of physical activity, the high level of physical activity significantly reduced risk of lung cancer among women with 10% [pooled RR = 0.90, 95% CI = 0.82 to 0.99].

The investigators found in subgroup analyses compared with the low level of physical activity, the high level of physical activity significantly reduced risk of lung cancer among men with 19% [pooled RR = 0.81, 95% CI = 0.73 to 0.90].

The investigators found smokers with a high level of physical activity were associated with a 10% lower risk for lung cancer [RR = 0.90, 95% CI = 0.84 to 0.97], while the association was not significant among non-smokers [RR = 0.95, 95% CI = 0.88 to 1.03].

Subgroups analysis stratified by whether the studies adjusted for smoking intensity and durations yielded the same magnitude of RR.

However, the RR for subgroups without adjustment for dietary factors was 0.74 [95% CI = 0.71 to 0.77], which was significantly lower than that with dietary factors adjusted [RR = 0.89, 95% CI = 0.84 to 0.95].

The investigators found in sensitivity analyses, the pooled RRs ranged from 0.82 [95% CI = 0.76 to 0.89] to 0.86 [95% CI = 0.81 to 0.92]. The trend was generally similar with the overall analysis.

The investigators concluded a high level of physical activity reduces risk of lung cancer among smokers. Large interventional studies are expected to further verify these findings. If the inverse association, as well as the effect modification by smoking status, reflects a causal relation, future precision prevention of lung cancer by increased physical activity may be more effective when targeting to smokers rather than non-smokers.

Original title:
Association Between Physical Activity and Lower Risk of Lung Cancer: A Meta-Analysis of Cohort Studies by Liu Y, Li Y, […], Fan XX.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6349707/

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Objectives:
Is there a relationship between nut consumption and metabolic syndrome (MetS)?

Study design:
This review article included a total of 11 observational studies (6 cross-sectional and 5 prospective cohort studies), which involved a total of 89,224 participants.

Results and conclusions:
The investigators found nut consumption significantly reduced risk of metabolic syndrome with 16% [overall multivariable adjusted RR = 0.84, 95% CI = 0.76-0.92, p  0.001].

The investigators found in subgroup analysis tree nut consumption significantly reduced risk of metabolic syndrome with 3% [RR = 0.97, 95% CI = 0.94-1.00, p =0.04]. However, this reduced risk was not significant in peanuts [RR = 1.01, 95% CI = 0.96-1.06, p = 0.68].

The investigators concluded nut consumption reduces risk of metabolic syndrome. However, this reduced risk is only found in tree nuts, not in peanuts. More well-designed studies with detailed specifications of nut varieties are needed to further elaborate the issues examined in this meta-analysis.

Original title:
Relationship Between Nut Consumption and Metabolic Syndrome: A Meta-Analysis of Observational Studies by Zhang Y and Zhang DZ.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30716015

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Objectives:
Taurine is central to many physiological processes, some of which are augmented by exogenous supply and have the potential to facilitate endurance performance; however, its independent effects on performance have not been systematically analyzed. Therefore, this review article has been conducted.

Does supplementation of taurine improve human endurance performance?

Study design:
This review article included 10 peer-reviewed articles. A sub-analysis of time-to-exhaustion (TTE) trials (n = 7) was also performed.

The doses of taurine ranged from 1 to 6 g/day and were provided in single doses and for up to 2 weeks among a range of subjects.

Results and conclusions:
The investigators found that taurine supplementation significantly improved overall endurance performance [Hedges' g = 0.40, 95% CI = 0.12-0.67, p = 0.004], which was similar in TTE trials [Hedges' g = 0.43, 95% CI = 0.12-0.75, p = 0.007].

The investigators found no differences between acute or chronic supplementation for the full sample [p = 0.897] or the TTE group [p = 0.896].

The investigators found that the dose of taurine did not moderate its effect on endurance performance [p > 0.05].

The investigators concluded that human endurance performance can be improved by orally ingesting a single dose of taurine in varying amounts (1-6 g).

Original title:
The Effects of an Oral Taurine Dose and Supplementation Period on Endurance Exercise Performance in Humans: A Meta-Analysis by Waldron M, Patterson SD, […], Jeffries O.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29546641

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Objectives:
Has flavonoid supplementation potential against obesity?

Study design:
This review article included 58 RCTs.
Analysis endpoints were calculated as the mean difference between baseline and post-treatment.
Flavonoids were in subclasses of flavanols, flavonols, isoflavones, flavanones, anthocyanins and proanthocyanidins. They were mostly in the form of supplements and dosages varying from 40 to 1300 mg/day.

Results and conclusions:
The investigators found among flavonoid subclasses, flavanols showed potential for decreasing BMI, in the overall population [MD = -0.28 kg/m², p = 0.04, n = 21] and in the subgroups of Asians [MD = -0.42 kg/m², p = 0.046, n = 13], ages 50 years [MD = -0.50 kg/m², p = 0.008, n = 14], BMI ≥25 kg/m² [MD = -0.30 kg/m², p = 0.049, n = 15] and at doses ≥500 mg/day [MD = -0.36 kg/m², p = 0.049, n = 12].

The investigators found among flavonoid subclasses, isoflavones also significantly decreased BMI of non-Asian populations [MD = -0.26 kg/m², p = 0.035, n = 13] and doses ≥75 mg/day [MD = -0.34 kg/m², p = 0.027, n = 8].

The investigators found in the overall assessment, flavanols also significantly decreased waist circumference [MD = -0.60 cm, p = 0.02, n = 18] but had no significant effect on body fat percentage.

The investigators found the available trials did not reveal significant effects from flavonols, flavanones and anthocyanins on the specified anthropometric measures.

The investigators concluded that flavanols, particularly ≥500 mg/day and isoflavones, particularly ≥75 mg/day have potential against obesity.

Original title:
Flavanols are potential anti-obesity agents, a systematic review and meta-analysis of controlled clinical trials by Akhlaghi M, Ghobadi S, […], Mohammadian F.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29759310

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Objectives:
Carbohydrate-restricted diets may increase low-density lipoprotein cholesterol (LDL-cholesterol or bad cholesterol) and thereby cardiovascular risk. Therefore, this review article has been conducted.

Do carbohydrate restriction diets increase cholesterol and triglycerides levels in overweight/obese adults?

Study design:
This review article included 8 RCTs with a total of 1,633 participants, of which 818 in carbohydrate-restricted diet group (intervention group) and 815 low-fat diet group (control group).

All RCTs had more than 100 participants with duration of at least 6 months.

Results and conclusions:
The investigators found when compared with low-fat diets, carbohydrate-restricted diets showed no significant difference in LDL-cholesterol levels after 6, 12 and 24 months.
Although an overall pooled analysis statistically favoured low-fat diets [0.07 mmol/L, 95% CI = 0.02-0.13, p = 0.009], this was clinically insignificant.

The investigators found when compared with low-fat diets, carbohydrate-restricted diets significant increased HDL-cholesterol (good cholesterol) levels [0.08 mmol/L, 95% CI = 0.06-0.11, p 0.00001] after 6 and 12 months.
These favourable changes were more marked in the subgroup with very-low carbohydrate content [50 g/d: 0.12 mmol/L, 95% CI = 0.10-0.14, p  0.00001].

The investigators found when compared with low-fat diets, carbohydrate-restricted diets significant reduced plasma triglycerides levels [-0.13 mmol/L, 95% CI = -0.19 to -0.08, p  0.00001 after 6 and 12 months.
These favourable changes were more marked in the subgroup with very-low carbohydrate content [50 g/d: -0.19 mmol/L, 95% CI = -0.26 to -0.12, p = 0.02].

The investigators concluded large randomized controlled trials (RCTs) of at least 6 months duration with carbohydrate restriction, particularly 50 g/d carbohydrates, is superior in improving HDL-cholesterol and triglycerides levels in overweight/obese adults when compared with low-fat diets. Dietary guidelines should consider carbohydrate restriction as an alternative dietary strategy for the prevention/management of dyslipidemia for populations with cardiometabolic risk.

Original title:
Effects of carbohydrate-restricted diets on low-density lipoprotein cholesterol levels in overweight and obese adults: a systematic review and meta-analysis by Gjuladin-Hellon T, Davies IG, […], Amiri Baghbadorani R.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30544168

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50 grams of carbohydrates per day corresponds to a diet with 10 En% carbohydrates.
The easiest way to follow a diet with 10 En% carbohydrates is to choose only meals/products with 10 En% carbohydrates.
However, the most practical way to follow a diet with 10 En% carbohydrates is all meals/products that you eat on a daily basis should contain on average 10 En% carbohydrates. Check here which products contain 10 En% carbohydrates.

Objectives:
Cocoa and dark chocolate (DC) have been reported to be effective for health promotion; however the exact effect of cocoa/dark chocolate on anthropometric measures have not been yet defined. Therefore, this review article has been conducted.

Has cocoa/dark chocolate supplementation positive effect on weight, BMI and waist circumference (WC)?   

Study design:
This review article included a total of 35 RCTs, investigating the effects of cocoa/dark chocolate on weight, BMI and waist circumference.

Results and conclusions:
The investigators found meta-analysis did not suggest any significant effect of cocoa/dark chocolate supplementation on:
-body weight [-0.108 kg, 95% CI = -0.262 to 0.046 p = 0.168]
-BMI [-0.014 kg/m², 95% CI = -0.105 to 0.077, p = 0.759] and
-WC [0.025 cm, 95% CI = -0.083 to 0.129, p = 0.640].

The investigators found, however, subgroup analysis revealed that weight and BMI were significantly reduced with ≥ 30g chocolate per day during 4-8 weeks.

Furthermore, supplementation of ≥ 30g chocolate per day during 4-8 weeks significantly reduced waist circumference in non-linear fashion [r = 0.042, p-nonlinearity = 0.008].

The investigators concluded that ≥ 30g chocolate per day during 4-8 weeks reduce weight, BMI and waist circumference.

Original title:
Does cocoa/dark chocolate supplementation have favorable effect on body weight, body mass index and waist circumference? A systematic review, meta-analysis and dose-response of randomized clinical trials by Kord-Varkaneh H, Ghaedi E, […], Shab-Bidar S.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29553824

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Objectives:
Modifiable factors that reduce the burden of the metabolic syndrome (MetS), particularly plant-derived biomarkers, have been a recent focus of rising interest. Therefore, this review article has been conducted.

Do dietary carotenoids reduce risk of metabolic syndrome?  

Study design:
This review article included 11 cross-sectional studies.
Publication bias was absent and harvest plots indicated consistency upon replication for β-carotene and total carotenoid exposures.

Results and conclusions:
The investigators found dietary total carotenoids intake significantly reduced risk of metabolic syndrome with 44% [pooled OR = 0.66, 95% CI = 0.56-0.78, 1 SD ∼ 0.82 µmol/L, n = 5 studies]. This reduced risk was the strongest for β-carotene, followed by α-carotene and β-crypotoxanthin.

The investigators found no association between retinol (vitamin A from animal products) and risk of metabolic syndrome [pooled OR = 1.00, 95% CI = 0.88-1.13, 1 SD ∼ 2.14 µmol/L, n = 6 studies].

The investigators concluded that carotenoids, particularly β-carotene, followed by α-carotene and β-crypotoxanthin may reduce risk of metabolic syndrome. May reduce because this review article only included cross-sectional studies and no cohort studies.

Original title:
Carotenoids, vitamin A, and their association with the metabolic syndrome: a systematic review and meta-analysis by Beydoun MA, Chen X, [...], Canas JA.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30202882

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Objectives:
What are the effects of ginger intake on weight loss, glycemic control and lipid profiles among overweight (BMI>25) and obese (BMI>30) subjects?

Study design:
This review article included 14 RCTs with in total of 473 subjects.

Results and conclusions:
The investigators found that supplementation with ginger significantly decreased among overweight (BMI>25) and obese (BMI>30) subjects:
-body weight (BW) [SMD -0.66, 95% CI = -1.31 to -0.01, p = 0.04];
-waist-to-hip ratio (WHR) [SMD = -0.49, 95% CI = -0.82 to -0.17, p = 0.003];
-hip ratio (HR) [SMD = -0.42, 95% CI = -0.77 to -0.08, p = 0.01];
-fasting glucose [SMD = -0.68, 95% CI = -1.23 to -0.05, p = 0.03] and;
-insulin resistance index (HOMA-IR) [SMD= -1.67, 95% CI = -2.86 to -0.48, p = 0.006].

The investigators found that supplementation with ginger significantly increased HDL-cholesterol (good cholesterol) levels [SMD = 0.40, 95% CI = 0.10 to 0.70, p = 0.009] among overweight (BMI>25) and obese (BMI>30) subjects.

The investigators found, however, that supplementation with ginger had no detrimental effect on:
-body mass index (BMI) [SMD = -0.65, 95% CI = -1.36 to 0.06, p = 0.074];
-insulin [SMD = -0.54, 95% CI = -1.43 to 0.35, p = 0.23];
-triglycerides [SMD = -0.27, 95% CI = -0.71 to 0.18, p = 0.24];
-total cholesterol [SMD = -0.20, 95% CI = -0.58 to 0.18, p = 0.30] and;
-LDL-cholesterol [SMD = -0.13, 95% CI = -0.51 to 0.24, p = 0.48].

The investigators concluded that ginger intake reduces body weight, waist-to-hip ratio, hip ratio, fasting glucose and insulin resistance index and increases HDL-cholesterol (good cholesterol), but has no affect on insulin, BMI, triglycerides, total- and LDL-cholesterol (bad cholesterol) levels among overweight and obese subjects.

Original title:
The effects of ginger intake on weight loss and metabolic profiles among overweight and obese subjects: A systematic review and meta-analysis of randomized controlled trials by Maharlouei N, Tabrizi R, […], Asemi Z.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29393665

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Persons with overweight are advised to choose products/meals with maximum 30 En% fat, maximum 7 En% saturated fat, maximum 0.2 grams salt per 100 kcal and minimum 1.5 grams fiber per 100 kcal. Check here which products/meals are suitable for persons with overweight.
 

Objectives:
Older adults experience age-related physiological changes that affect body weight and body composition. In general, nutrition and exercise have been identified as potent stimulators of protein synthesis in skeletal muscle. Milk proteins are excellent sources of all the essential amino acids and may represent an ideal protein source to promote muscle anabolism in older adults undergoing resistance training. However, several randomized control trials (RCTs) have yielded mixed results on the effects of milk proteins supplementation in combination with resistance training on body weight and composition. Therefore, this review article has been conducted.

Does supplementation of milk protein alone or in combination with resistance training, increase fat-free mass in older adults (age ≥ 60 years)?

Study design:
This review article included 10 RCTs involving 574 participants (mean age range from 60 to 80.8 years).

There was no statistical evidence of publication bias among the studies.

Results and conclusions:
The investigators found overall, the combination of milk proteins supplementation and resistance training had no significant effect on fat mass [0.30, 95% CI = -0.25 to 0.86 kg] or body weight [1.02, 95% CI = -0.01 to 2.04 kg].

The investigators found, however, a positive effect of milk proteins supplementation paired with resistance training on fat-free mass [0.74, 95% CI = 0.30 to 1.17 kg].

The investigators found greater fat-free mass gains were observed in studies that included more than 55 participants [0.73, 95% CI = 0.30 to 1.16 kg] and in studies that enrolled participants with aging-related medical conditions [1.60, 95% CI = 0.92 to 2.28 kg].

The investigators concluded supplementation of milk protein, in combination with resistance training, is effective to elicit fat-free mass gain in older adults (age ≥ 60 years).

Original title:
Effects of Milk Proteins Supplementation in Older Adults Undergoing Resistance Training: A Meta-Analysis of Randomized Control Trials by Hidayat K, Chen GC, […], Qin LQ.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29380851

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