Nutritional advice

Objectives:
Do diets rich in protein causually reduce body weight of adults with overweight or obesity? 

Study design:
This review article included 37 RCTs.
The diets were included during a mean of 32 weeks interventions, ranging from 8 to 104 weeks.

There was no publication bias.

Results and conclusions:
The investigators found protein intake (ranging from 18-59 energy percentage [En%]) significantly reduced body weight by 1.6 kg [95% CI = 1.2 to 2.0 kg, I2 = 56%] compared to controls (digestible carbohydrate, fiber, fat or no supplementation (no placebo used)).
This result was also found in sensitivity analysis.

The investigators found the effect size of dietary protein in body weight management was dependent on specific phenotypes, where individuals with prediabetes had more benefit compared to individuals with normoglycemia.
Furthermore, individuals without the obesity risk allele (AA genotype) had more benefit compared to individuals with the obesity risk alleles (AG and GG genotypes).

The investigators concluded that diets rich in protein (18-59 energy percentage [En%]) during 32 weeks causally have a moderate beneficial effect on body weight management of adults with overweight or obesity.

Original title:
Are Dietary Proteins the Key to Successful Body Weight Management? A Systematic Review and Meta-Analysis of Studies Assessing Body Weight Outcomes after Interventions with Increased Dietary Protein by Hansen TT, Astrup A and Sjödin A.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8468854/

Additional information of El Mondo:
Find more information/studies on protein consumption and overweight right here.

A diet rich in protein with 18-59 energy percentage [E%] or a diet with 18-59 En% protein means that the amounts of protein contribute 18 to 59% to the total calories (kcal) of the diet.
If the diet contains 2000 kcal, 90 grams of protein contribute 18% to this 2000 kcal.
1 gram of protein gives 4 kcal. Thus 90 grams of protein provide 360 kcal (90x4 kcal) and 360 kcal is 18% of 2000 kcal.

The most easy way to follow a diet rich in protein with 18-59 energy percentage is to choose only meals/products with 18-59 En% protein. Check here which products contain 18-59 En% protein.

However, the most practical way to follow a diet with 18-59 En% protein is, all meals/products that you eat on a daily basis should contain on average 18-59 En% protein.

To do this, use the 7-points nutritional profile app to see whether your daily diet contains 18-59 En% protein.

A high-protein diet is a diet with at least 20 En% protein.

 

Objectives:
The association between vitamin C and metabolic syndrome (MetS) has been evaluated in several epidemiological studies with conflicting results. Therefore, this review article has been conducted.

Do dietary vitamin C intake and circulating vitamin C level reduce risk of metabolic syndrome? 

Study design:
This review article included 26 cross-sectional studies and 2 cohort studies with a total number of 110,771 participants. 23 studies were related to the dietary vitamin C level.
The sample size ranged from 143 to 27,656 persons.
The dietary vitamin C level was assessed by food-frequency questionnaire (FFQ) in 4 studies, a 24-h or 3-day recall in 18 studies and a 4-day record in 1 study.

No evidence of publication bias existed according to Begg's rank correlation test [p = 0.495].

Results and conclusions:
The investigators found when compared to the lowest dietary vitamin C intake, that the highest dietary vitamin C intake significantly reduced risk of metabolic syndrome with 7% [overall multivariable-adjusted RR = 0.93, 95% CI = 0.88 to 0.97, p = 0.003, I2 = 54.5%, p = 0.003]. The above findings were confirmed in cross-sectional studies [RR = 0.92, 95% CI = 0.87 to 0.97, p = 0.001] and 24-h or 3-day recall [RR = 0.89, 95% CI = 0.86 to 0.93, p 0.001] studies.

The investigators found when compared to the lowest circulating vitamin C level, that the highest circulating vitamin C level significantly reduced risk of metabolic syndrome with 40% [overall multivariable-adjusted RR = 0.60, 95% CI = 0.49 to 0.74, p 0.001, I2 = 22.7%, p = 0.249].

The investigators concluded that both the dietary and the circulating vitamin C level reduce risk of metabolic syndrome. However, due to the limitation of the available evidence, more well-designed prospective studies are still needed.

Original title:
Vitamin C and Metabolic Syndrome: A Meta-Analysis of Observational Studies by Guo H, Ding J, [...], Zhang Y.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8531097/

Additional information of El Mondo:
Find more information/studies on vitamin C consumption and overweight right here.

In practice, a lot of dietary vitamin C intake amounts to 200 to 300 grams of vegetables and 2-5 pieces of fruit per day. Vitamin C is found in fruit and vegetables.

A high circulating vitamin C level can be obtained through vitamin C-rich food and/or taking vitamin C supplements.

 

Objectives:
The associations between dietary carbohydrate and diverse health outcomes remain controversial and confusing. Therefore, this review article (meta-analyse) has been conducted.

What is the association between dietary carbohydrate intake and diverse health outcomes?

Study design:
This review article included 43 meta-analyses of observational research studies with 23 health outcomes, including cancer (n = 26), mortality (n = 4), metabolic diseases (n = 4), digestive system outcomes (n = 3) and other outcomes [coronary heart disease (n = 2), stroke (n = 1), Parkinson's disease (n = 1) and bone fracture (n = 2)].

This umbrella review summarized 281 individual studies with 13,164,365 participants.

33.3% studies were considered to be of high quality and 66.7% of moderate quality.

Results and conclusions:
The investigators found highly suggestive evidence showed that dietary carbohydrate intake significantly increased risk of metabolic syndrome with 25% [adjusted summary odds ratio = 1.25, 95% CI = 1.15 to 1.37].

The investigators found suggestive evidence showed that dietary carbohydrate intake significantly decreased risk of esophageal adenocarcinoma with 43% [adjusted summary hazard ratio = 0.57, 95% CI = 0.42 to 0.78].

The investigators found suggestive evidence showed that dietary carbohydrate intake significantly increased risk of all-cause mortality with 19% [adjusted summary hazard ratio 1.19, 95% CI = 1.09 to 1.30].

The investigators concluded despite the fact that numerous systematic reviews and meta-analyses have explored the relationship between carbohydrate intake and diverse health outcomes, there is no convincing evidence of a clear role of carbohydrate intake. However, highly suggestive evidence shows carbohydrate intake is associated with higher risk of metabolic syndrome. Suggestive evidence shows carbohydrate intake is associated with higher risk of all-cause mortality and lower risk of esophageal adenocarcinoma.

Original title:
Dietary Carbohydrate and Diverse Health Outcomes: Umbrella Review of 30 Systematic Reviews and Meta-Analyses of 281 Observational Studies by Liu YS, Wu QJ […], Zhao YH.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8116488/

Additional information of El Mondo:
Find more information/studies on carbohydrate consumption and obesity/overweight right here.

Objectives:
What is the association between red meat and poultry consumption and the risk of metabolic syndrome?

Study design:
This review article included 9 prospective cohort studies, which involved a total of 21,869 participants.
Among them, 8 studies were identified for red meat consumption.

No publication bias was observed according to the Begg's rank-correlation test and the Egger's test.  

Results and conclusions:
The investigators found that red meat consumption was significantly associated with a higher risk of 35% for metabolic syndrome [multi-variable adjusted RR = 1.35, 95% CI = 1.13 to 1.62, p = 0.001, I2 = 54.4%, p = 0.032].  
The same results were obtained in subgroup analysis for >5 years follow-up [RR = 1.36, 95% CI = 1.09 to 1.7, p = 0.006], non-National Cholesterol Education Program-Adult Treatment Panel (NCEP-ATP III) [RR = 1.34, 95% CI = 1.12 to 1.62, p = 0.002], Non-Asia [RR = 1.51, 95% CI = 1.29 to 1.77, p 0.001], adjustment of BMI [RR = 1.4, 95% CI = 1.23 to 1.6, p 0.001] and physical activity studies [RR = 1.48, 95% CI = 1.29 to 1.71, p 0.001].

The investigators found that unprocessed red meat consumption was significantly associated with a higher risk of 32% for metabolic syndrome [multi-variable adjusted RR = 1.32, 95% CI = 1.14 to 1.54, p = 0.0003, I2 = 0%, p = 0.397].  

The investigators found that processed red meat consumption was significantly associated with a higher risk of 48% for metabolic syndrome [multi-variable adjusted RR = 1.48, 95% CI = 1.11 to 1.97, p = 0.007, I2 = 64.7%, p = 0.097].  

The investigators found that poultry consumption was significantly associated with a lower risk of 15% for metabolic syndrome [multi-variable adjusted RR = 0.85, 95% CI = 0.75 to 0.97, p = 0.02, I2 = 0%, p = 0.707].  

The investigators concluded that red meat (processed and unprocessed) consumption is associated with a higher risk of metabolic syndrome, whereas, poultry consumption is associated with a lower risk of metabolic syndrome. More well-designed randomized controlled trials are still needed to address the issues further.

Original title:
Association of Red Meat and Poultry Consumption With the Risk of Metabolic Syndrome: A Meta-Analysis of Prospective Cohort Studies by Guo H, Ding J, [...], Zhang Y.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8295459/

Additional information of El Mondo:
Find more information/studies on meat consumption and obesity/overweight right here.

Objectives:
Nuts are recommended for cardiovascular health, yet concerns remain that nuts may contribute to weight gain due to their high energy density. Therefore, this review article has been conducted.

Does nut consumption contribute to an increased adiposity risk?

Study design:
This review article included 6 prospective cohort studies with 569,910 participants and 86 RCTs with 114 comparisons and 5,873 participants.

Results and conclusions:
The investigators found nuts consumption was significantly associated with a lower risk of 7% for incidence of overweight/obesity [RR = 0.93, 95% CI = 0.88 to 0.98, p 0.001, moderate certainty of evidence] in prospective cohort studies.

The investigators found RCTs showed no adverse effect of nuts on body weight [MD = 0.09 kg, 95% CI = -0.09 to 0.27 kg, p 0.001, high certainty of evidence].

The investigators found meta-regression showed that higher nut intake was significantly associated with reductions in body weight and body fat.

The investigators concluded that current evidence demonstrates the concern that nut consumption contributes to increased adiposity appears unwarranted.

Original title:
Are fatty nuts a weighty concern? A systematic review and meta-analysis and dose-response meta-regression of prospective cohorts and randomized controlled trials by Nishi SK, Viguiliouk E, [...], Sievenpiper JL.

Link:
https://pubmed.ncbi.nlm.nih.gov/34494363/

Additional information of El Mondo:
Find more information/studies on nut consumption and obesity/overweight right here.

Objectives:
Diets with high glycemic index (GI) or high glycemic load (GL) have been linked to important risk factors associated with the development of metabolic syndrome (MetS), such as dyslipidemia, higher blood glucose and insulin concentrations. However, the role of GI and GL in relation to metabolic syndrome is still understudied and controversial. Therefore, this review article has been conducted.

Does high dietary GI or GL increase risk of metabolic syndrome?

Study design:
This review article included 1 cohort study and 11 cross-sectional studies with a total sample size of 36,295 subjects.

Results and conclusions:
The investigators found, the pooled effect sizes from the 9 studies indicated high versus low dietary GI was significantly associated with increased risk of 5% for metabolic syndrome [OR = 1.05, 95% CI = 1.01 to 1.09, I2 = 58.1%, p = 0.004].
This finding was supported by all subgroup analyses except where studies used 24-h recalls for dietary assessment.

The investigators found, additionally, a linear dose-response investigation revealed that each 5-point increment in GI was associated with 2% increase in the risk of metabolic syndrome [OR = 1.02, 95% CI = 1.01 to 1.02].
Howver, non-linear pattern was insignificant [p-nonlinearity = 0.63].

The investigators found, moreover, pooled effect sizes from 10 studies suggested that no association was found between the GL and metabolic syndrome with results remaining consistent in all subgroup analyses.

The investigators concluded that high dietary GI increases risk of metabolic syndrome. Nutrition policy and clinical practices should encourage a diet with low GI. Future studies should include both GI and GL and different criteria of metabolic syndrome to provide a better comparison.

Original title:
Glycemic index, but not glycemic load, is associated with an increased risk of metabolic syndrome: Meta-analysis of observational studies by Askari M, Dehghani A, […], Alizadeh S.

Link:
https://pubmed.ncbi.nlm.nih.gov/33928722/

Additional information of El Mondo:
Find more information/studies on GI and overweight right here.

A diet with low GI is a diet with GI of 55 or lower.

Objectives:
Excess body weight, including overweight and obesity, is one of the major factors influencing human health and plays an important role in the global burden of disease. Carotenoids serve as precursors of vitamin A-related retinoids and are considered to have potential effects on many diseases. However, the influence of carotenoids on people with excess body weight is unclear. Therefore, this review article has been conducted.

Does carotenoid supplementation reduce risk of overweight and obesity in overweight or obese subjects?

Study design:
This review article included 7 randomized controlled trials (RCTs) and 8 observational studies with 28,944 subjects and data on multiple carotenoid subgroups, including lycopene, astaxanthin, cryptoxanthin, α-carotene, and β-carotene.

In all included RCTs, the intervention duration was 20 days at the shortest and 16 weeks at the longest and the range of intervention doses was 1.2-60 mg/d.

Results and conclusions:
The investigators found that the insufficiency of serum carotenoids significantly increased risk of overweight and obesity with 73% [OR = 1.73, 95% CI = 1.57 to 1.91, p 0.001].

The investigators found, moreover, carotenoid supplementation was significantly associated with body weight reductions [SMD = -2.34 kg, 95% CI = -3.80 to -0.87 kg, p 0.001], body mass index decrease [SMD = -0.95 kg/cm², 95% CI = -1.88 to -0.01 kg/cm², p 0.001] and waist circumference losses [SMD = -1.84 cm, 95% CI = -3.14 to -0.54 cm, p 0.001].

The investigators concluded that 1.2-60 mg/d carotenoid supplementation reduces risk of overweight and obesity in overweight or obese subjects. Furthermore, an insufficiency of serum carotenoids is a risk factor for overweight and obesity. Additional data from large clinical trials are needed.

Original title:
The association between carotenoids and subjects with overweight or obesity: a systematic review and meta-analysis by Yao N, Yan S, […], Cui W.

Link:
https://pubmed.ncbi.nlm.nih.gov/33977977/

Additional information of El Mondo:
Find more information/studies on carotenoid consumption and obesity/overweight right here.

Am I overweight?
 

Objectives:
The evidence on the association between obesity and atrial fibrillation (AF) recurrence was equivocal. Therefore, this review article (meta-analysis) has been conducted.

Does obesity increase risk of atrial fibrillation recurrence in patients undergoing catheter ablation?

Study design:
This review article included 20 studies with 52,771 patients.

Results and conclusions:
The investigators found that obesity was significantly associated with higher atrial fibrillation recurrence [OR = 1.30, 95% C = 1.16 to 1.47, p 0.001, I2 = 72.7%] and similar rate of adverse events [OR = 1.21, 95% CI = 0.87 to 1.67, p = 0.264, I2 = 23.9%] in patients undergoing catheter ablation.

The investigators found meta-regression showed that the association varied by age [coefficient = -0.03, p = 0.024].

The investigators found meta-analysis of highest versus lowest BMI showed that the highest group had higher atrial fibrillation recurrence [OR = 1.37, 95% CI = 1.18 to 1.58, p 0.001, I2 = 64.9%] and adverse events [OR = 2.02, 95% CI = 1.08 to 3.76, p = 0.028, I2 = 49.5%] in patients undergoing catheter ablation.

The investigators found the dose-response relationship for BMI and atrial fibrillation recurrence was nonlinear [p nonlinearity 0.001], the curve became steeper at 30-35 kg/m².

The investigators found for adverse events, an increase of 1% for every 1 kg/m² increase in BMI [OR = 1.01, 95% CI = 1.00 to 1.02, p = 0.001], the relationship was nonlinear [p nonlinearity = 0.001].

The investigators concluded that obesity is associated with higher atrial fibrillation recurrence in patients undergoing catheter ablation. High BMI is associated with a higher risk for adverse events.

Original title:
BMI and atrial fibrillation recurrence post catheter ablation: A dose-response meta-analysis by Pranata R, Henrina J, […], Munawar M.

Link:
https://pubmed.ncbi.nlm.nih.gov/33544873/

Additional information of El Mondo:
Find more information/studies on cardiovascular diseases and obesity/overweight right here.

Catheter ablation is a procedure that uses radiofrequency energy (similar to microwave heat) to destroy a small area of heart tissue that is causing rapid and irregular heartbeats. Destroying this tissue helps restore your heart’s regular rhythm. Catheter ablation is also called radiofrequency ablation.

Am I overweight?
 

Objectives:
A few randomized controlled trials (RCTs) have assessed the effect of brown rice consumption on metabolic parameters (such as, weight, height, waist circumference, fasting glucose, LDL, HDL, total cholesterol, triglycerides and blood pressure) compared to white rice, with inconsistent findings. Therefore, this review article has been conducted.

Is the effect of brown rice on adiposity indices (such as, weight, height and waist circumference), lipid profile (such as, LDL, HDL, total cholesterol and triglycerides) and glycemic markers (such as, fasting blood glucose) higher compared to white rice in adult subjects?

Study design:
This review article included 13 RCTs.
In accordance with Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, the certainly of the included evidence was low and very low.

Results and conclusions:
The investigators found brown rice significantly reduced:
weight by -1.63 kg [95% CI = -2.15 to -1.11, I2 = 97%, n = 6];
body mass index (BMI) by -0.58 kg/m² [95% CI = -0.78 to -0.37, I2 = 96%, n = 6] and;
waist circumference by -2.56 cm [95% CI = -4.86 to -0.26, I2 = 88%, n = 5] compared with white rice.

The investigators found, moreover, brown rice had no significant effect on lipid profile and glycemic markers.

The investigators found pre-germinated brown rice significantly declined:
weight by -1.75 kg [95% CI = -2.70 to -0.81, I2 = 99%, n = 4];
total cholesterol by -24.22 mg/dL [95% CI = -33.03 to -15.41, I2 = 78%, n = 5];
triglyceride (TG) by -43.28 mg/dL [95% CI = -74.05 to -12.50, I2 = 90%, n = 5];
low-density lipoprotein (LDL or bad cholesterol) by -20.05 mg/dL [95% CI = -29.57 to -10.52, I2 = 71%, n = 5] and;
fasting blood glucose (FBG) by -15.83 mg/dL [95% CI = -25.20 to -6.46, I2 = 91%, n = 5] compared to white rice.

The investigators concluded brown rice has anti-obesity effects in comparison with white rice. However, it has no beneficial effects on lipid profile and glycemic markers. Furthermore, pre-germinated brown rice has better functional effects on promoting lipid profile and fasting blood glucose compared to brown rice.

Original title:
The effect of brown rice compared to white rice on adiposity indices, lipid profile, and glycemic markers: a systematic review and meta-analysis of randomized controlled trials by Golzarand M, Toolabi K, […], Mirmiran P.

Link:
https://pubmed.ncbi.nlm.nih.gov/33905269

Additional information of El Mondo:
Find more information/studies on rice consumption and obesity/overweight right here.

Objectives:
Several mechanisms have been proposed for the effect of vitamin E on weight loss. Yet various interventional studies with wide ranges of doses and durations have reported contradictory results. Therefore, this review article has been conducted.

Does vitamin E supplementation reduce overweight?

Study design:
This review article included 24 RCTs.

Results and conclusions:
The investigators found there was no significant effect of vitamin E supplements on weight [WMD = 0.15, 95% CI = -1.35 to 1.65, p = 0.847], body mass index (BMI) [WMD = 0.04, 95% CI = -0.29 to 0.37, p = 0.815] and waist circumference (WC) [WMD = -0.19 kg, 95% CI = -2.06 to 1.68, p = 0.842], respectively.

The investigators found, however, subgroup analysis revealed that vitamin E supplementation in studies conducted on participants with normal BMI (18.5-24.9) had increasing impact on BMI [p = 0.047].  

The investigators concluded there is no significant effect of vitamin E supplementation on weight, BMI and waist circumference (WC). However, vitamin E supplementation increases BMI in participants with normal BMI (18.5-24.9).

Original title:
Can vitamin E supplementation affect obesity indices? A systematic review and meta-analysis of twenty-four randomized controlled trials by Emami MR, Jamshidi S, […], Aryaeian N.

Link:
https://pubmed.ncbi.nlm.nih.gov/33632535/

Additional information of El Mondo:
Find more information/studies on vitamin E and obesity/overweight right here.

Objectives:
Recent systematic reviews and meta-analyses of randomized, double-blind, placebo-controlled trials (double-blind, placebo-controlled RCTs) have reported controversial findings regarding the associations between calcium supplements on the risk of cardiovascular disease (CVD). Therefore, this review article has been conducted.

Do calcium supplements increase risk of cardiovascular disease (CVD)?

Study design:
This review article included 13 RCTs with 28,935 participants in an intervention group (group with calcium supplements) and 14,243 in a control group (group without calcium supplements).

The mean age of the study participants was 66.3 years (range: 35 to 97 years) and 92.8% of those were women.
Publication bias was not observed.

Results and conclusions:
The investigators found calcium supplements significantly increased the risk of cardiovascular disease with 15% in healthy postmenopausal women [RR = 1.15, 95% CI = 1.06 to 1.25, I2 = 0.0%, n = 14].

The investigators found calcium supplements significantly increased the risk of coronary heart disease with 16% in healthy postmenopausal women [RR = 1.16, 95% CI = 1.05 to 1.28, I2 = 0.0%, n = 9].

The investigators found in the subgroup meta-analysis, dietary calcium intake of 700-1000 mg per day or supplementary calcium intake of 1000 mg per day significantly increased the risk of cardiovascular disease and coronary heart disease.

The investigators concluded that the use of calcium supplements (1000 mg per day) is significantly associated with the increased risk of cardiovascular disease and coronary heart disease by 15%, specifically in postmenopausal women. These findings should be explicitly confirmed by conducting further RCTs with cardiovascular disease outcome measures as well as the incidence of osteoporosis or fractures as the primary endpoints.

Original title:
Calcium Supplements and Risk of Cardiovascular Disease: A Meta-Analysis of Clinical Trials by Myung SK, Kim HB, […], Oh SW.

Link:
https://pubmed.ncbi.nlm.nih.gov/33530332/

Additional information of El Mondo:
Find more information/studies on calcium consumption, elderly and cardiovascular diseases right here.

Objectives:
Vitamin D deficiency during pregnancy or infancy is associated with adverse growth in children. No systematic review has been conducted to summarize available evidence on the effect of vitamin D supplementation in pregnancy and infancy on growth and body composition in children. Therefore, this review article has been conducted.

Does vitamin D supplementation during pregnancy or infancy increase adiposity (severe or morbid overweight) risk in childhood?

Study design:
This review article included 12 RCTs with a total of 4,583 participants.
The doses of vitamin D in the intervention group (group with vitamin D supplements) were 60,000 IU/4 weeks (1,500 mcg/4 weeks) or 60,000 IU/8 weeks and in the control group (group without vitamin D supplements) was 400 IU/day.

Results and conclusions:
The investigators found vitamin D supplementation during pregnancy was associated with higher triceps skinfold thickness (mm) [MD = 0.33, 95% CI = 0.12 to 0.54, I2 = 34%] in neonates.

The investigators found vitamin D supplementation during pregnancy or infancy was associated with significantly increased length for age z-score in infants at 1 year of age [MD = 0.29, 95% CI = 0.03 to 0.54, I2 = 0%].

The investigators found vitamin D supplementation during pregnancy or infancy was associated with lower body mass index (BMI) (kg/m²) [MD = -0.19, 95% CI = -0.34 to -0.04, I2 = 0%] and body mass index z-score (BMIZ) [MD = -0.12, 95% CI = -0.21 to -0.04, I2 = 0%] in offspring at 3-6 years of age.

The investigators found vitamin D supplementation during early life was not observed to be associated with children’s bone, lean or fat mass.

The investigators concluded vitamin D supplementation during pregnancy or infancy is associated with reduced adiposity (severe or morbid overweight) in childhood. Future large well-designed double blinded RCTs are needed to assess the effectiveness of vitamin D supplementation in early life on children’s bone health, lean mass and adiposity.

Original title:
Effect of Vitamin D Supplementation in Early Life on Children's Growth and Body Composition: A Systematic Review and Meta-Analysis of Randomized Controlled Trials by Ma K, Wei SQ, [...], Wen SW.

Link:
https://www.mdpi.com/2072-6643/13/2/524/htm

Additional information of El Mondo:
Find more information/studies on vitamin D and obesity/overweight right here.