Inverse association of long-term nut consumption with weight gain and risk of overweight/obesity: a systematic review

A Cross-Sectional Study on the Association of Walnut Consumption with Obesity and Relative Fat Mass among United States Adolescents and Young Adults in NHANES (2003-2020)

Background

Walnuts contain nutrients and phytochemicals that can promote metabolic health. However, the high energy content of walnuts along with other nuts raises the concern that consuming nuts promotes obesity.

Objectives

We sought to investigate the associations between consumption of walnuts as well as other nuts and measures of obesity in adolescents and young adults.

Methods

This study included 8874 adolescents (12-19 y) and 10,323 young adults (20-39 y) from 8 waves of National Health and Nutrition Examination Survey data (2003-2020). The associations of consumption of 1) walnuts only (WO); 2) walnuts with other nuts (WON); 3) other nuts (ON); and 4) no nuts (NN) with obesity status and relative fat mass (RFM) were assessed using logistic and linear regressions stratified by age group and sex. Sample weights were used in all statistical analyses.

Results

The mean daily intake of walnuts was not different between the 2 walnut consumption groups within each age group (adolescents: 2.18 [standard error (SE) 0.14] g; P = 0.917; young adults: 4.23 [0.37] g; P = 0.682). The WON group had the lowest prevalence of obesity (adolescents: 8.3%; young adults: 21.1%) while the NN group had the highest prevalence (adolescents: 24.1%; young adults: 35.4%). The models indicated lower odds of obesity in adolescent girls (odds ratio [OR]: 0.27; P < 0.05) and young adult women (OR: 0.58; P < 0.05) who consumed WON than in those who consumed NN. In both young women and girls, RFM was significantly lower in the WON and ON groups than the NN group (P < 0.001). In young men, WON consumption was also associated with a lower RFM (OR: -1.24; 95% confidence interval: -2.21, -0.28) compared with NN consumption.

Conclusions

For adolescents girls and young women, dietary intake of walnuts combined with other nuts has the strongest inverse association with measures of obesity.

Nuts and seeds - a scoping review for Nordic Nutrition Recommendations 2023

Background

Nuts and seeds have been part of diets in most of the world for millenniums, and they have also been consumed in the Nordic and Baltic countries for centuries. Consumption of nuts and seeds is linked with various health outcomes. Therefore, when updating the Nordic Nutrition Recommendations (NNR), summarizing the best evidence on key health outcomes from the consumption of nuts and seeds is essential.

Objectives

This study aims to evaluate the updated evidence on the consumption of nuts and seeds and health outcomes regarded relevant for the Nordic and Baltic countries, as well as their dose-response relationship presented in updated systematic reviews and meta-analyses.

Method

The scoping review is built on a de novo systematic review and an umbrella review published in 2022 on the consumption of nuts and seeds and its various health outcomes, including cardiovascular disease and diabetes.

Results

Intake of nuts and seeds is associated with a lower risk of cardiovascular diseases, with evidence assessed as probable. This conclusion is mirrored by evidence from trials on biomarkers for chronic diseases. An intake of a serving of nuts of 28-30 g/day compared to not eating nuts is estimated to translate into approximately 20% relative reduction in the risks of cardiovascular disease and premature deaths. For cancers, consumption of a serving of nuts is inversely associated with cancer mortality. However, for type 2 diabetes, there are mixed and inconclusive results. Additionally, there are inverse associations between nut consumption and respiratory and infectious disease mortality. Allergies for nuts are seen among 1-2% of the population.

Conclusion

Overall, the current evidence supports dietary recommendations to increase nut consumption to a serving of nuts and seeds per day for people without allergies to these foods.

Almonds vs. carbohydrate snacks in an energy-restricted diet: Weight and cardiometabolic outcomes from a randomized trial

OBJECTIVE

This study evaluated weight and cardiometabolic outcomes after a 3-month energy-restricted diet (-30%) containing almonds (almond-enriched diet [AED]) or containing carbohydrate-rich snacks (nut-free control diet [NFD]) (Phase 1), followed by 6 months of weight maintenance (Phase 2).

METHODS

Participants (25-65 years old) with overweight or obesity (BMI 27.5-34.9 kg/m2 ) were randomly allocated to AED (n = 68) or NFD (n = 72).

RESULTS

Both groups lost weight during Phase 1 (p < 0.001) (mean [SE], -7.0 [0.5] kg AED vs. -7.0 [0.5] kg NFD, p = 0.858) and Phase 2 (p = 0.009) (-1.1 [0.5] kg AED vs. -1.3 [0.6] NFD, p = 0.756), with improvements in percentage lean mass after Phase 2 (4.8% [0.3%], p < 0.001). Reductions occurred in fasting glucose (-0.2 [0.07] mmol/L, p = 0.003), insulin (-8.1 [4.0] pmol/L, p = 0.036), blood pressure (-4.9 [0.8] mm Hg systolic, -5.0 [0.5] mm Hg diastolic, p < 0.001), total cholesterol (-0.3 [0.1] mmol/L), low-density lipoprotein (LDL) (-0.2 [0.1] mmol/L), very low-density lipoprotein (-0.1 [0.03] mmol/L), and triglycerides (-0.3 [0.06] mmol/L) (all p < 0.001), and high-density lipoprotein increased (0.1 [0.02] mmol/L, p = 0.011) by the end of Phase 2 in both groups. There were group by time interactions for lipoprotein particle concentrations: very small triglyceride-rich (-31.0 [7.7] nmol/L AED vs. -4.8 [7.9] nmol/L NFD, p = 0.007), small LDL (-109.3 [40.5] nmol/L AED vs. -20.7 [41.6] nmol/L NFD, p = 0.017), and medium LDL (-24.4 [43.4] nmol/L AED vs. -130.5 [44.4] nmol/L NFD, p = 0.045).

CONCLUSIONS

An energy-restricted AED resulted in weight loss and weight loss maintenance comparable to an energy-restricted NFD, and both diets supported cardiometabolic health. The AED resulted in greater improvements in some lipoprotein subfractions, which may enhance reductions in cardiovascular risk.

Association of Tree Nut Consumption with Cardiovascular Disease and Cardiometabolic Risk Factors and Health Outcomes in US Adults: NHANES 2011-2018

Background

Tree nuts are nutrient dense, and their consumption has been associated with improvements in health outcomes.

Objective

To estimate the usual tree nut intake and examine the association between tree nut consumption and cardiometabolic (CM) health outcomes in a nationally representative sample of US adults.

Methods

Cross-sectional data were analyzed from a sample of 18,150 adults aged ≥ 20y who provided at least one reliable 24-h dietary recall and had complete data for the variables of interest in the NHANES 2011-2018. Tree nut consumers were defined as those consuming ≥ ¼ ounce/d (7.09 g). The National Cancer Institute Method was used to estimate the usual tree nut intake among consumers. Measurement error calibrated regression models were used to assess the association between tree nut consumption and each health outcome of interest.

Results

Approximately 8% of all participants (n = 1238) consumed tree nuts and had a mean ± SE usual intake of 39.5 ± 1.8 g/d. Tree nut consumers were less likely to have obesity (31% vs. 40%, P < 0.001) and low high-density lipoprotein cholesterol (22% vs. 30%, P < 0.001) compared with nonconsumers. Moreover, tree nut consumers had a lower mean waist circumference (WC) (97.1 ± 0.7 vs. 100.5 ± 0.3 cm, P < 0.001) and apolipoprotein B (87.5 ± 1.2 vs. 91.8 ± 0.5 mg/dL, P = 0.004) than nonconsumers. After adjusting models for demographics and lifestyle covariates, the difference in WC between average intake (33.7 g/d) and low threshold intake (7.09/g) of tree nuts was -1.42 ± 0.58 cm (P = 0.005).

Conclusions

Most US adults do not consume tree nuts, yet modest consumption was associated with decreased prevalence of cardiovascular disease and CM risk factors and improvement for some health outcome measures.

Nuts and berries from agroforestry systems in temperate regions can form the foundation for a healthier human diet and improved outcomes from diet-related diseases

Agroforestry is a specific type of agroecosystem that includes trees and shrubs with the potential to yield nutrient-rich products that contribute to human health. This paper reviews the literature on the human health benefits of tree nut and berry species commonly associated with agroforestry systems of the United States, considering their potential for preventing certain diet-related diseases. Emphasis is placed on those diseases that are most closely associated with poor outcomes from COVID-19, as they are indicators of confounding health prognoses. Results indicate that tree nuts reduce the risk of coronary heart disease, and walnuts (Juglans species) are particularly effective because of their unique fatty acid profile. Berries that are grown on shrubs have the potential to contribute to mitigation of hypertension, prevention of Type II diabetes, and reduced risk of cardiovascular disease. To optimize human health benefits, plant breeding programs can focus on the traits that enhance the naturally-occurring phytochemicals, through biofortification. Value-added processing techniques should be selected and employed to preserve the phytonutrients, so they are maintained through the point of consumption. Agroforestry systems can offer valuable human health outcomes for common diet-related diseases, in addition to providing many environmental benefits, particularly if they are purposefully designed with that goal in mind. The food system policies in the U.S. might be reoriented to prioritize these food production systems based on the health benefits.

Comparing the effects of consuming almonds or biscuits on body weight in habitual snackers: A one-year randomized controlled trial

PURPOSE

Almonds are nutrient-rich, providing a healthier alternative to many snack foods. Studies report health benefits with regular almond consumption without adverse weight gain. However, most interventions have been relatively short or have included additional dietary advice. Taking a pragmatic approach, we compared consumption of almonds versus biscuits on body weight and other health outcomes in a population of regular snackers of discretionary foods, hypothesizing the almonds will displace some of the less healthful snacks in their current diets.

METHODS

We randomly assigned 136 non-obese habitual discretionary snack consumers to receive almonds or biscuits daily for one-year. These isocaloric snacks provided either 10% of participants' total energy (TE) requirements or 1030 kJ (equivalent to 42.5 g almonds), whichever was greater. Anthropometry, blood biomarkers, diet, appetite, sleep, and, physical activity, were assessed at baseline, 3, 6, and 12 months, and body composition and resting metabolic rate at baseline and 12 months.

RESULTS

The difference in changes for body weight from baseline to 12 months was not statistically significant (geometric means 67.1 kg and 69.5 kg for almonds and 66.3 kg and 66.3 kg for biscuits, P = 0.275). There were no statistically significant differences in changes for body composition or other non-dietary outcomes (all P ≥ 0.112). Absolute intakes of protein; total, polyunsaturated, and monosaturated fat; fibre; vitamin E; calcium; copper; magnesium; phosphorous; and zinc, and % TE from total monounsaturated, and polyunsaturated fat statistically significantly increased from baseline (all P ≤ 0.033), while % TE from carbohydrate and sugar statistically significantly (both P ≤ 0.014) decreased from baseline, in the almond compared to the biscuit group.

CONCLUSIONS

Almonds can be incorporated into the diets of habitual snackers to improve diet quality, without evidence for changes in body weight, compared to a popular discretionary snack food.

TRIAL REGISTRATION

ACTRN12618001758291 https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=375610&isReview=true.

Determination of the level of evidence for the association between different food groups/items and dietary fiber intake and the risk of cardiovascular diseases and hypertension: An umbrella review

Evidence has suggested that nutrition is a preventive factor against cardiovascular disease (CVD) risk. Because of a sharp growth in published meta-analyses and pooled analyses in recent years, a reassessment of old evidence is needed. We aimed to determine the level of evidence for the association between the consumption of different food groups/items and dietary fiber and the incidence risk of CVDs, hypertension, and atrial fibrillation from meta-analyses and pooled analyses of observational studies. Databases Scopus, PubMed/Medline, and Web of Science were searched for related studies. Fifty-eight articles met the inclusion criteria for evidence grading. In summary, grading the level of evidence showed a suggestive inverse association between the higher consumption of fruits, whole grains, fish, legumes, nuts, and dietary fibers with the incidence risk of hypertension and different types of CVD. Also, there was a probable inverse association between the higher consumption of total and low-fat dairy products and the risk of hypertension. Higher red meat consumption had a probable association with the increased risk of ischemic stroke. Higher consumption of processed meat and poultry also had a suggestive direct association with the incidence risk of stroke and hypertension. We have tried to present a comprehensive and useful overview of the level of evidence based on the most updated findings. The summary of results in the current umbrella review can be a helpful tool for nutritionists, dietitians, and researchers to establish new studies and identify research gaps in related issues.

Nut-enriched energy restricted diet has potential to decrease hunger in women at cardiometabolic risk: a randomized controlled trial (Brazilian Nuts Study)

Successful weight management represents a challenge to obesity control. Evidence suggests that nut consumption promotes a prolonged satiety response. Therefore, we hypothesize that nuts could be associated with greater weight loss in comparison to a control group, and we evaluate the acute and long-term effects of Brazilian nuts (BN: 15 g of Brazil nuts + 30 g of cashew nuts) included in an energy-restricted intervention on food intake, appetite, and peptide hormones. We conducted an 8-week, randomized, open-label, controlled, parallel-arm clinical trial with 28 women at cardiometabolic risk who received an energy-restricted diet containing BN or an energy-restricted nut-free diet (control). At baseline and after 8 weeks of intervention, subjective postprandial appetite ratings were assessed using a visual analog scale (VAS) before and after consumption (0, 10, 60, 120, 180, and 240 minutes) of a 437-kcal nut-enriched (BN group) or nut-free (control) breakfast meal. Subsequently, an ad libitum lunch was served, and the participants completed another VAS at 280 minutes. Plasma concentrations of ghrelin, glucose-dependent insulinotropic polypeptide, glucagon-like peptide 1, and leptin were measured at fasting and postprandially at 60, 120, and 240 minutes. Last, subsequent reported 24-hour energy intake was assessed in a free-living setting. BN consumption did not have acute effects on food intake, appetite, or peptide hormones. However, after an 8-week intervention, postprandial ghrelin (difference between post- and preintervention area under the curve) decreased in the BN group in comparison to the control (mean difference, 1978 pg/mL/min, 95% CI, 27-3929 pg/mL/min; P = .047) and therefore, an energy-restricted diet containing demonstrated potential to decrease hunger in cardiometabolic risk women.

Consumption of Nuts and Seeds and Health Outcomes Including Cardiovascular Disease, Diabetes and Metabolic Disease, Cancer, and Mortality: An Umbrella Review

Consumption of nuts and seeds is associated with a range of health outcomes. Summarizing the best evidence on essential health outcomes from the consumption of nuts is essential to provide optimal recommendations. Our objective is to comprehensively assess health outcome associations related to the consumption of nuts and seeds, using a culinary definition including tree nuts and peanuts (registered in PROSPERO: CRD42021258300). Health outcomes of interest include cardiovascular disease, cancer, diabetes, obesity, respiratory disease, mortality, and their disease biomarkers. We present associations for high compared with low consumption, per serving, and dose-response relations. MEDLINE, Embase, Cochrane, and Epistemonikos were searched and screened for systematic reviews and meta-analyses. Evidence was extracted from 89 articles on the consumption of nuts and relevant health outcomes, including 23 articles with meta-analysis on disease and mortality, 66 articles on biomarkers for disease, and 9 articles on allergy/adverse outcomes. Intake of nuts was associated with reduced risk of cardiovascular diseases and related risk factors, with moderate quality of evidence. An intake of 28 g/d nuts compared with not eating nuts was associated with a 21% RR reduction of cardiovascular disease (including coronary heart disease incidence and mortality, atrial fibrillation, and stroke mortality), an 11% risk reduction of cancer deaths, and 22% reduction in all-cause mortality. Nut consumption was also inversely associated with mortality from respiratory diseases, infectious diseases, and diabetes; however, associations between nut consumption and diabetes incidence were mixed. Meta-analyses of trials on biomarkers for disease generally mirrored meta-analyses from observational studies on cardiovascular disease, cancers, and diabetes. Allergy and related adverse reactions to nuts were observed in 1-2% of adult populations, with substantial heterogeneity between studies. Overall, the current evidence supports dietary recommendations to consume a handful of nuts and seeds per day for people without allergies to these foods.

Mixed Tree Nuts, Cognition, and Gut Microbiota: A 4-Week, Placebo-Controlled, Randomized Crossover Trial in Healthy Nonelderly Adults

BACKGROUND

Beneficial effects of nut supplementation on cognitive function have previously been demonstrated in young and older adults. Alterations to gut microbiota have also been shown following tree nut consumption. However, no data exists on the effects of nuts on cognition and intestinal microbial communities assessed within the same study.

OBJECTIVES

The study aimed to examine the effects of daily consumption of tree nuts for 4 wk on cognitive function (primary outcome), mood, metabolomics, and gut microbial species (secondary outcomes) in healthy, nonelderly adults.

METHODS

This randomized, placebo-controlled, double-blind, counterbalanced crossover study assessed the effects of 4 wk of supplementation with 30 g/d mixed tree nuts versus placebo on cognition and mood in 79 healthy adults aged 18-49 y. Metabolic responses, gut bacterial community structure, and the potential for these to impact cognition were explored using a multi-omic approach. Bacterial community analysis was conducted in Quantitative Insights Into Microbial Ecology 2 (QIIME2).

RESULTS

Mixed model analysis indicated that nut consumption led to significant improvements to accuracy (placebo M = 92.2% compared with NUTS M = 94.5%; P = 0.019) and speed of response (placebo M = 788 ms compared with NUTS M = 757 ms; P = 0.004) on a picture recognition task. No significant changes to bacterial community α or β diversity were observed when comparing nut consumption to the placebo arm. However, an unclassified Lachnospiraceae amplicon sequence variant (ASV) was significantly enriched in participants when supplemented with nuts (P = 0.015). No correlations were observed between the changes to picture recognition and the changes to the unclassified Lachnospiraceae ASV. There were no significant changes to the urinary metabolome.

CONCLUSIONS

These findings indicate a positive effect of nut on cognition following only 4 wk of consumption in a healthy nonelderly sample, as well as upregulation of a microbial taxa associated with gut health. The effects appear to be independent of one another, but further exploration is required in those experiencing cognitive decline and/or gut dysbiosis.

Perceptions of Nut Consumption amongst Australian Nutrition and Health Professionals: An Online Survey

Habitual nut consumption is associated with reduced risk of chronic diseases; however, consumption levels in Australia are below recommendations. This study examined perceptions and knowledge regarding nut consumption among Australian healthcare professionals and their provision of nut consumption recommendations. A cross-sectional online survey of Australian health professionals was conducted in February-April 2020. Questions in the survey included demographic details, participants' perceptions of nut consumption, and nut consumption recommendations they may make to clients and patients. A total of 204 health professionals completed the survey, of which 84% were dietitians or nutritionists. Health professionals demonstrated basic nutritional knowledge regarding nut consumption; however, non-dietitians/nutritionists lacked knowledge of long-term benefits of nut consumption. Dietitians/nutritionists were more likely to agree that nuts are healthy and do not cause weight gain when compared to non-dietitians/nutritionists (p = 0.021). A total of 63% of health professionals advised at least some of their clients to eat more nuts, and this was higher among dietitians/nutritionists (68%) than non-dietitians/nutritionists (31%). While basic nutritional knowledge regarding nut consumption was observed among all health professionals, there is scope for further education, particularly for non-dietitians/nutritionists, to ensure that nutrition information provided to patients and clients is accurate and reflects the current evidence base.

Nutrition and physical activity: An Obesity Medicine Association (OMA) Clinical Practice Statement 2022

Background

This Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) on Nutrition and Physical Activity provides clinicians an overview of nutrition and physical activity principles applicable to the care of patients with increased body fat, especially those with adverse fat mass and adiposopathic metabolic consequences.

Methods

The scientific information and clinical guidance is based upon referenced evidence and derived from the clinical perspectives of the authors.

Results

This OMA CPS on Nutrition and Physical Activity provides basic clinical information regarding carbohydrates, proteins, fats (including trans fats, saturated fats, polyunsaturated fats, and monounsaturated fats), general principles of healthful nutrition, nutritional factors associated with improved health outcomes, and food labels. Included are the clinical implications of isocaloric substitution of refined carbohydrates with saturated fats and vice-versa, as well as definitions of low-calorie, very low-calorie, carbohydrate-restricted, and fat-restricted dietary intakes. Specific dietary plans discussed include carbohydrate-restricted diets, fat-restricted diets, very low-calorie diets, the Mediterranean diet, Therapeutic Lifestyle diet, Dietary Approaches to Stop Hypertension (DASH), ketogenic (modified Atkins) diet, Ornish diet, Paleo diet, vegetarian or vegan diet (whole food/plant-based), intermittent fasting/time restricted feeding, and commercial diet programs. This clinical practice statement also examines the health benefits of physical activity and provides practical pre-exercise medical evaluation guidance as well as suggestions regarding types and recommended amounts of dynamic (aerobic) training, resistance (anaerobic) training, leisure time physical activity, and non-exercise activity thermogenesis (NEAT). Additional guidance is provided regarding muscle physiology, exercise prescription, metabolic equivalent tasks (METS), and methods to track physical activity progress.

Conclusion

This Obesity Medicine Association Clinical Practice Statement on Nutrition and Physical Activity provides clinicians an overview of nutrition and physical activity. Implementation of appropriate nutrition and physical activity in patients with pre-obesity and/or obesity may improve the health of patients, especially those with adverse fat mass and adiposopathic metabolic consequences.

Composition of Brazil Nut (Bertholletia excels HBK), Its Beverage and By-Products: A Healthy Food and Potential Source of Ingredients

The consumption of plant-based beverages is a growing trend and, consequently, the search for alternative plant sources, the improvement of beverage quality and the use of their by-products, acquire great interest. Thus, the purpose of this work was to characterize the composition (nutrients, phytochemicals and antioxidant activity) of the Brazil nut (BN), its whole beverage (WBM), water-soluble beverage (BM-S), and its by-products of the beverage production: cake, sediment fraction (BM-D), and fat fraction (BM-F). In this study, advanced methodologies for the analysis of the components were employed to assess HPLC-ESI-QTOF (phenolic compounds), GC (fatty acids), and MALDI-TOF/TOF (proteins and peptides). The production of WBM was based on a hot water extraction process, and the production of BM-S includes an additional centrifugation step. The BN showed an interesting nutritional quality and outstanding content of unsaturated fatty acids. The investigation found the following in the composition of the BN: phenolic compounds (mainly flavan-3-ols as Catechin (and glycosides or derivatives), Epicatechin (and glycosides or derivatives), Quercetin and Myricetin-3-O-rhamnoside, hydroxybenzoic acids as Gallic acid (and derivatives), 4-hydroxybenzoic acid, ellagic acid, Vanillic acid, p-Coumaric acid and Ferulic acid, bioactive minor lipid components (β-Sitosterol, γ-Tocopherol, α-Tocopherol and squalene), and a high level of selenium. In beverages, WBM had a higher lipid content than BM-S, a factor that influenced the energy characteristics and the content of bioactive minor lipid components. The level of phenolic compounds and selenium were outstanding in both beverages. Hydrothermal processing can promote some lipolysis, with an increase in free fatty acids and monoglycerides content. In by-products, the BM-F stood out due to its bioactive minor lipid components, the BM-D showed a highlight in protein and mineral contents, and the cake retained important nutrients and phytochemicals from the BN. In general, the BN and its beverages are healthy foods, and its by-products could be used to obtain healthy ingredients with appreciable biological activities (such as antioxidant activity).

Are fatty nuts a weighty concern? A systematic review and meta-analysis and dose-response meta-regression of prospective cohorts and randomized controlled trials

Nuts are recommended for cardiovascular health, yet concerns remain that nuts may contribute to weight gain due to their high energy density. A systematic review and meta-analysis of prospective cohorts and randomized controlled trials (RCTs) was conducted to update the evidence, provide a dose-response analysis, and assess differences in nut type, comparator and more in subgroup analyses. MEDLINE, EMBASE, and Cochrane were searched, along with manual searches. Data from eligible studies were pooled using meta-analysis methods. Interstudy heterogeneity was assessed (Cochran Q statistic) and quantified (I2 statistic). Certainty of the evidence was assessed by Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Six prospective cohort studies (7 unique cohorts, n = 569,910) and 86 RCTs (114 comparisons, n = 5873) met eligibility criteria. Nuts were associated with lower incidence of overweight/obesity (RR 0.93 [95% CI 0.88 to 0.98] P < 0.001, "moderate" certainty of evidence) in prospective cohorts. RCTs presented 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). Meta-regression showed that higher nut intake was associated with reductions in body weight and body fat. Current evidence demonstrates the concern that nut consumption contributes to increased adiposity appears unwarranted.

Adherence to a Plant-Based Diet and Consumption of Specific Plant Foods-Associations with 3-Year Weight-Loss Maintenance and Cardiometabolic Risk Factors: A Secondary Analysis of the PREVIEW Intervention Study

Plant-based diets are recommended by dietary guidelines. This secondary analysis aimed to assess longitudinal associations of an overall plant-based diet and specific plant foods with weight-loss maintenance and cardiometabolic risk factors. Longitudinal data on 710 participants (aged 26–70 years) with overweight or obesity and pre-diabetes from the 3-year weight-loss maintenance phase of the PREVIEW intervention were analyzed. Adherence to an overall plant-based diet was evaluated using a novel plant-based diet index, where all plant-based foods received positive scores and all animal-based foods received negative scores. After adjustment for potential confounders, linear mixed models with repeated measures showed that the plant-based diet index was inversely associated with weight regain, but not with cardiometabolic risk factors. Nut intake was inversely associated with regain of weight and fat mass and increments in total cholesterol and LDL cholesterol. Fruit intake was inversely associated with increments in diastolic blood pressure, total cholesterol, and LDL cholesterol. Vegetable intake was inversely associated with an increment in diastolic blood pressure and triglycerides and was positively associated with an increase in HDL cholesterol. All reported associations with cardiometabolic risk factors were independent of weight change. Long-term consumption of nuts, fruits, and vegetables may be beneficial for weight management and cardiometabolic health, whereas an overall plant-based diet may improve weight management only.

The Role of Physical Fitness in the Relationship between Nut Consumption and Body Composition in Young Adults

The main objective of this study was to estimate the association between nut consumption and body composition-related measures and to examine whether this relationship is mediated by cardiorespiratory fitness (CRF) and the muscle strength index (MSI) in young adults. A cross-sectional study involving college students (n = 354) aged 18-30 years from a Spanish public university was conducted. Body composition and fitness components were assessed using standard methods. Nut consumption was evaluated using a Food-Frequency Questionnaire. ANCOVA models were used to assess the mean differences in physical fitness and body composition by nut consumption categories. Hayes's PROCESS macro was applied for mediation and interaction analyses adjusted for the main confounders. Young adults with high nut consumption (≥5 portions of 30 g/week) showed significantly higher values of physical fitness components and fat-free mass and lower values of adiposity-related measures than their peers in the lowest categories of nut consumption (˂1 portion/week) (p < 0.05). No significant interaction between CRF and nut consumption on body composition was found. In the mediation analysis, CRF and MSI acted as full mediators of the relationship of nut consumption with fat-free mass and waist circumference/height index. Otherwise, CRF and MSI partially mediated the relationship between nut consumption and body mass index and percent of fat mass. Finally, nut consumption, per se, does not appear to have a significant impact on body composition indicators because these associations have been shown to be partially (for BMI and %BF) or entirely (for ratio WC/height and fat-free mass) explained by CRF and MSI.

A Comprehensive Review of Almond Clinical Trials on Weight Measures, Metabolic Health Biomarkers and Outcomes, and the Gut Microbiota

This comprehensive narrative review of 64 randomized controlled trials (RCTs) and 14 systematic reviews and/or meta-analyses provides an in-depth analysis of the effect of almonds on weight measures, metabolic health biomarkers and outcomes, and the colonic microbiota, with extensive use of figures and tables. Almonds are a higher energy-dense (ED) food that acts like a lower ED food when consumed. Recent systematic reviews and meta-analyses of nut RCTs showed that almonds were the only nut that had a small but significant decrease in both mean body mass and fat mass, compared to control diets. The biological mechanisms for almond weight control include enhanced displacement of other foods, decreased macronutrient bioavailability for a lower net metabolizable energy (ME), upregulation of acute signals for reduced hunger, and elevated satiety and increased resting energy expenditure. The intake of 42.5 g/day of almonds significantly lowered low-density lipoprotein cholesterol (LDL-C), 10-year Framingham estimated coronary heart disease (CHD) risk and associated cardiovascular disease (CVD) medical expenditures. Diastolic blood pressure (BP) was modestly but significantly lowered when almonds were consumed at >42.5 g/day or for >6 weeks. Recent RCTs suggest possible emerging health benefits for almonds such as enhanced cognitive performance, improved heart rate variability under mental stress, and reduced rate of facial skin aging from exposure to ultraviolet (UV) B radiation. Eight RCTs show that almonds can support colonic microbiota health by promoting microflora richness and diversity, increasing the ratio of symbiotic to pathogenic microflora, and concentrations of health-promoting colonic bioactives. Almonds are a premier healthy snack for precision nutrition diet plans.

Nut consumption and type 2 diabetes risk: a systematic review and meta-analysis of observational studies

BACKGROUND

Previous meta-analyses, with some methodological controversies, have assessed the relation between nut consumption and type 2 diabetes (T2D) risk and pointed to contradictory results, making desirable the performance of an updated meta-analysis.

OBJECTIVES

We aimed to systematically review and meta-analyze all the published studies investigating the relations of total nuts and different types of nuts-i.e., walnuts, peanuts, peanut butter, and total tree nuts-with the prevalence and incidence of T2D.

METHODS

A systematic search was conducted in the PubMed and Cochrane databases through 12 August, 2020. The inverse variance method with fixed-effect models was used to pool data across studies, expressed as risk ratios (RRs) or ORs and 95% CIs for prospective cohort and cross-sectional studies, respectively. The Cochran Q test and I2 statistics were used to test and quantify heterogeneity, respectively. Dose-response meta-analysis was also conducted.

RESULTS

Eight studies (5 prospective and 3 cross-sectional) were included in the quantitative synthesis. Meta-analyses of cross-sectional studies and prospective cohort studies, comparing the highest with the lowest categories, revealed a nonsignificant association between total nut consumption and T2D. Meta-analyses of prospective cohort studies showed an inverse association between peanut butter consumption and T2D incidence (RR: 0.87; 95% CI: 0.77, 0.98; I2 = 50.6%; Pheterogeneity = 0.16), whereas no association was observed between peanuts or tree nuts and T2D. There was no evidence of a linear dose-response or nonlinear dose-response gradient for total nut and peanut consumption in prospective cohort studies. The certainty of the evidence using NutriGrade was very low for all the exposures.

CONCLUSIONS

Current results do not demonstrate an association of total nut, peanut, or tree nut consumption with T2D. Peanut butter consumption may be inversely associated with this disease.This review protocol was registered at www.crd.york.ac.uk/prospero/ as CRD42020149756.

Barriers and Facilitators to Nut Consumption: A Narrative Review

Habitual nut intake is associated with a range of health benefits; however, population consumption data suggests that most individuals do not meet current recommendations for nut intake. The literature has highlighted a range of barriers and facilitators to nut consumption, which should be considered when designing strategies to promote nut intake. Common barriers include confusion regarding the effects of nut consumption on body weight, perceptions that nuts are high in fat, or too expensive, and challenges due to dentition issues or nut allergies. Conversely, demographic characteristics such as higher education and income level, and a healthier lifestyle overall, are associated with higher nut intakes. Health professionals appear to play an important role in promoting nut intake; however, research suggests that knowledge of the benefits of nut consumption could be improved in many health professions. Future strategies to increase nut intake to meet public health recommendations must clarify misconceptions of the specific benefits of nut consumption, specifically targeting sectors of the population known to have lower nut consumption, and educate health professionals to promote nut intake. In addition, given the relatively small body of evidence exploring barriers and facilitators to nut consumption, further research exploring these factors is justified.

Effects of passion fruit peel flour (Passiflora edulis f. flavicarpa O. Deg.) in cafeteria diet-induced metabolic disorders

ETHNOPHARMACOLOGICAL RELEVANCE

Passiflora edulis f. flavicarpa O. Deg. is a native Brazilian fruit known as sour or yellow passion fruit. From its peel, mainly in the northeast of Brazil, is produced a flour that is largely used as folk medicine to treat diabetes and other metabolic conditions.

AIM OF THE STUDY

The aim of the study was to show the effects of P. edulis peel flour (PEPF) in metabolic disorders caused by cafeteria diet in mice.

MATERIAL AND METHODS

The antioxidant activity in vitro of PEPF extract was determined by ferric reducing/antioxidant power, β-carotene/linoleic acid system and nitric oxide scavenging activity assay. C57BL/6 mice divided in 3 groups: Control group, fed on a standard diet (AIN); Cafeteria diet (CAF) group, fed on a cafeteria diet, and PEPF group, fed on a cafeteria diet containing 15% of PEPF, during 16 weeks. The glucose tolerance and insulin sensitivity were evaluated through the glucose tolerance test (GTT) and the insulin tolerance test (ITT). After the intervention period, blood, hepatic, pancreatic and adipose tissues were collected for biochemical and histological analysis. Cholesterol, triglyceride, interleukins and antioxidant enzymes were measured in the liver tissue.

RESULTS

PEPF extract presented antioxidant activity in the higher concentrations in the performed assays. The PEPF intake decreased the body weight gain, fat deposition, predominantly in the liver, improved the glucose tolerance and insulin sensitivity in metabolic changes caused by cafeteria diet.

CONCLUSION

Together, the data herein obtained points out that P. edulis peel flour supplementation in metabolic syndrome condition induced by CAF-diet, prevents insulin and glucose resistance, hepatic steatosis and adiposity.

Adipokines and Adipose Tissue-Related Metabolites, Nuts and Cardiovascular Disease

Adipose tissue is a complex structure responsible for fat storage and releasing polypeptides (adipokines) and metabolites, with systemic actions including body weight balance, appetite regulation, glucose homeostasis, and blood pressure control. Signals sent from different tissues are generated and integrated in adipose tissue; thus, there is a close connection between this endocrine organ and different organs and systems such as the gut and the cardiovascular system. It is known that functional foods, especially different nuts, may be related to a net of molecular mechanisms contributing to cardiometabolic health. Despite being energy-dense foods, nut consumption has been associated with no weight gain, weight loss, and lower risk of becoming overweight or obese. Several studies have reported beneficial effects after nut consumption on glucose control, appetite suppression, metabolites related to adipose tissue and gut microbiota, and on adipokines due to their fatty acid profile, vegetable proteins, l-arginine, dietary fibers, vitamins, minerals, and phytosterols. The aim of this review is to briefly describe possible mechanisms implicated in weight homeostasis related to different nuts, as well as studies that have evaluated the effects of nut consumption on adipokines and metabolites related to adipose tissue and gut microbiota in animal models, healthy individuals, and primary and secondary cardiovascular prevention.

Association between Adherence to the Mediterranean Diet and Physical Fitness with Body Composition Parameters in 1717 European Adolescents: The AdolesHealth Study

Obesity, low levels of physical fitness, and unhealthy eating patterns are responsible for part of the health problems of adolescents today. The current study aimed at examining the association between the adherence to the Mediterranean diet (MD), through each answer to the items of the Adherence to the MD Questionnaire (KIDMED), and physical fitness with body composition parameters (body mass index (BMI), percentage of body fat, and waist circumference) in 1717 European adolescents (N = 900 boys, N = 817 girls). Data of body composition, physical fitness results, and the answers to KIDMED were analyzed by the Student’s t-test. Additionally, the effect size (ES) was calculated and a Chi-square test analyzed the proportion of participants with and without over waist circumference, overfat, and overweight in each KIDMED question. The relative risk of suffering over waist circumference, overfat and overweight in relation to the responses was calculated by Odd-Ratio. Adherence to the MD did not influence the condition of over waist circumference, overfat and overweight, although certain dietary habits were identified as risk factors for their development. Over waist circumference, overfat, and overweight boys and girls presented higher levels of body mass, waist circumference, body fat percentage, and BMI (p < 0.001; ES = 1.73–3.38), as well as lower levels of all the parameters of the physical fitness analyzed (p < 0.001; ES = 0.45–1.08), except the handgrip test. A direct relationship between fitness and over waist circumference, overfat, and overweight was found.