Controversy and debate: Memory-Based Methods Paper 1: the fatal flaws of food frequency questionnaires and other memory-based dietary assessment methods

The Carbon Stable Isotope Ratio (CIR) as an Objective Biomarker of Added Sugar Intake: A Scoping Review of Current Evidence in Human Nutrition

Objective biomarkers of dietary intake are needed to advance nutrition research. The carbon stable isotope ratio (C13/C12; CIR) holds promise as an objective biomarker of added sugar (AS) and sugar-sweetened beverage (SSB) intake. This systematic scoping review presents the current evidence on CIRs from human studies. Search results (through April 12, 2024) yielded 6,297 studies and 24 final articles. Studies were observational (n=12), controlled feeding (n=10), or dietary interventions (n=2). CIRs were sampled from blood (n=23), hair (n=5), breath (n= 2), and/or adipose tissue (n=1). Most (n=17) conducted whole tissue (i.e., bulk) analysis, eight used compound specific isotope analysis (CSIA), and/or two studies used methods appropriate for analyzing breath. Studies were conducted in three concentrated geographic regions of the U.S. (n=7 Virginia; n=5 Arizona; n=4 Alaska), with only two studies conducted in other countries. Studies that used CSIA to examine the CIR from the non-essential amino acid alanine (CIR-Ala; n=4) and CIR analyzed from breath (n=2) provided the most robust evidence for CIR as an objective biomarker of AS and SSBs (R2 range 0.36-0.91). Studies using bulk analysis of hair or blood showed positive, but modest and more variable associations with AS and SSBs (R2 range 0.05-0.48). Few studies showed no association, particularly in non-U.S. populations and those with low AS and SSB intakes. Two studies provided evidence for CIR to detect changes in SSB intake in response to dietary interventions. Overall, the most compelling evidence supports CIR-Ala as an objective indicator of AS intake and breath CIR as an indicator of short term AS intake. Considering how to adjust for underlying dietary patterns remains an important area of future work and emerging methods using breath and CSIA warrant additional investigation. More evidence is needed to refine the utility and specificity of CIRs to measure AS and SSB intake.

Towards consistency in dietary pattern scoring: standardising scoring workflows for healthy dietary patterns using 24-h recall and two variations of a food frequency questionnair

Healthy dietary patterns such as the Mediterranean diet (MeDi), Dietary Approaches to Stop Hypertension (DASH) and the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) have been evaluated for their potential association with health outcomes. However, the lack of standardisation in scoring methodologies can hinder reproducibility and meaningful cross-study comparisons. Here we provide a reproducible workflow for generating the MeDi, DASH and MIND dietary pattern scores from frequently used dietary assessment tools including the 24-h recall tool and two variations of FFQ. Subjective aspects of the scoring process are highlighted and have led to a recommended reporting checklist. This checklist enables standardised reporting with sufficient detail to enhance the reproducibility and comparability of their outcomes. In addition to these aims, valuable insights in the strengths and limitations of each assessment tool for scoring the MeDi, DASH and MIND diet can be utilised by researchers and clinicians to determine which dietary assessment tool best meets their needs.

Forgetting how we ate: personalised nutrition and the strategic uses of history

Personalised nutrition (PN) has emerged over the past twenty years as a promising area of research in the postgenomic era and has been popularized as the new big thing out of molecular biology. Advocates of PN claim that previous approaches to nutrition sought general and universal guidance that applied to all people. In contrast, they contend that PN operates with the principle that "one size does not fit all" when it comes to dietary guidance. While the molecular mechanisms studied within PN are new, the notion of a personal dietary regime guided by medical advice has a much longer history that can be traced back to Galen's "On Food and Diet" or Ibn Sina's (westernized as Avicenna) "Canon of Medicine". Yet this history is either wholly ignored or misleadingly appropriated by PN proponents. This (mis)use of history, we argue helps to sustain the hype of the novelty of the proposed field and potential commodification of molecular advice that undermines longer histories of food management in premodern and non-Western cultures. Moreover, it elides how the longer history of nutritional advice always happened in a heavily moralized, gendered, and racialized context deeply entwined with collective technologies of power, not just individual advice. This article aims at offering a wider appreciation of this longer history to nuance the hype and exceptionalism surrounding contemporary claims.

Deficient butyrate metabolism in the intestinal microbiome is a potential risk factor for recurrent kidney stone disease

Intestinal microbiome dysbiosis is a known risk factor for recurrent kidney stone disease (KSD) with prior data suggesting a role for dysfunctional metabolic pathways other than those directly utilizing oxalate. To identify alternative mechanisms, the current study analyzed differences in the metabolic potential of intestinal microbiomes of patients (n = 17) and live-in controls (n = 17) and determined their relevance to increased risk for KSD using shotgun metagenomic sequencing. We found no differences in the abundance of genes associated with known oxalate degradation pathways, supporting the notion that dysfunction in other metabolic pathways plays a role in KSD. Further analysis showed decreased abundance of key enzymes involved in butyrate biosynthesis in patient intestinal microbiomes. Furthermore, de novo construction of microbial genomes showed that the majority of genes significantly enriched in non-stone formers are affiliated with Faecalibacterium prausnitzii, a major butyrate producer. Specifically pertaining to butyrate metabolism, the majority of abundant genes mapped back to F. prausnitzii, Alistipes spp., and Akkermansia muciniphila. No differences were observed in ascorbate or glyoxylate metabolic pathways. Collectively, these data suggest that impaired bacterial-associated butyrate metabolism may be an oxalate-independent mechanism that contributes to an increased risk for recurrent KSD. This indicates that the role of the intestinal microbiome in recurrent KSD is multi-factorial, which is representative of the highly intertwined metabolic nature of this complex environment. Future bacteria-based treatments must not be restricted to targeting only oxalate metabolism.

Meat consumption & positive mental health: A scoping review

The objective of this scoping review was to examine the breadth of the existing literature on the relation between meat consumption or meat abstention and positive psychological functioning. In April 2022, we conducted a systematic search of online databases (PubMed, PsycINFO, CINAHL Plus, Medline, Cochrane Library, and Web of Science) for primary research examining positive psychological functioning in meat consumers and those who abstain from meat. Thirteen studies met the inclusion/exclusion criteria, representing 89,138 participants (54,413 females and 33,863 males) with 78,562 meat consumers and 10,148 meat abstainers (13-102 years) from multiple geographic regions. The primary outcomes were life satisfaction, "positive mental health", self-esteem, and vigor. The secondary outcomes were "meaning in life", optimism, positive emotions, and psychological well-being. Eight of the 13 studies demonstrated no differences between the groups on positive psychological functioning, three studies showed mixed results, and two studies showed that compared to meat abstainers, meat consumers had greater self-esteem, "positive mental health", and "meaning in life". Studies varied substantially in methods and outcomes. Although a small minority of studies showed that meat consumers had more positive psychological functioning, no studies suggested that meat abstainers did. There was mixed evidence for temporal relations, but study designs precluded causal inferences. Our review demonstrates the need for future research given the equivocal nature of the extant literature on the relation between meat consumption and meat abstention and positive psychological functioning.

Comparing Self-Reported Dietary Intake to Provided Diet during a Randomized Controlled Feeding Intervention: A Pilot Study

Systematic and random errors based on self-reported diet may bias estimates of dietary intake. The objective of this pilot study was to describe errors in self-reported dietary intake by comparing 24 h dietary recalls to provided menu items in a controlled feeding study. This feeding study was a parallel randomized block design consisting of a standard diet (STD; 15% protein, 50% carbohydrate, 35% fat) followed by either a high-fat (HF; 15% protein, 25% carbohydrate, 60% fat) or a high-carbohydrate (HC; 15% protein, 75% carbohydrate, 10% fat) diet. During the intervention, participants reported dietary intake in 24 h recalls. Participants included 12 males (seven HC, five HF) and 12 females (six HC, six HF). The Nutrition Data System for Research was utilized to quantify energy, macronutrients, and serving size of food groups. Statistical analyses assessed differences in 24 h dietary recalls vs. provided menu items, considering intervention type (STD vs. HF vs. HC) (Student's t-test). Caloric intake was consistent between self-reported intake and provided meals. Participants in the HF diet underreported energy-adjusted dietary fat and participants in the HC diet underreported energy-adjusted dietary carbohydrates. Energy-adjusted protein intake was overreported in each dietary intervention, specifically overreporting beef and poultry. Classifying misreported dietary components can lead to strategies to mitigate self-report errors for accurate dietary assessment.

Trans-fatty acid blood levels of industrial but not natural origin are associated with cardiovascular risk factors in patients with HFpEF: a secondary analysis of the Aldo-DHF trial

BACKGROUND

Industrially processed trans-fatty acids (IP-TFA) have been linked to altered lipoprotein metabolism, inflammation and increased NT-proBNP. In patients with heart failure with preserved ejection fraction (HFpEF), associations of TFA blood levels with patient characteristics are unknown.

METHODS

This is a secondary analysis of the Aldo-DHF-RCT. From 422 patients, individual blood TFA were analyzed at baseline in n = 404 using the HS-Omega-3-Index® methodology. Patient characteristics were: 67 ± 8 years, 53% female, NYHA II/III (87/13%), ejection fraction ≥ 50%, E/e' 7.1 ± 1.5; NT-proBNP 158 ng/L (IQR 82-298). A principal component analysis was conducted but not used for further analysis as cumulative variance for the first two PCs was low. Spearman's correlation coefficients as well as linear regression analyses, using sex and age as covariates, were used to describe associations of whole blood TFA with metabolic phenotype, functional capacity, echocardiographic markers for LVDF and neurohumoral activation at baseline and after 12 months.

RESULTS

Blood levels of the naturally occurring TFA C16:1n-7t were inversely associated with dyslipidemia, body mass index/truncal adiposity, surrogate markers for non-alcoholic fatty liver disease and inflammation at baseline/12 months. Conversely, IP-TFA C18:1n9t, C18:2n6tt and C18:2n6tc were positively associated with dyslipidemia and isomer C18:2n6ct with dysglycemia. C18:2n6tt and C18:2n6ct were inversely associated with submaximal aerobic capacity at baseline/12 months. No significant association was found between TFA and cardiac function.

CONCLUSIONS

In HFpEF patients, higher blood levels of IP-TFA, but not naturally occurring TFA, were associated with dyslipidemia, dysglycemia and lower functional capacity. Blood TFAs, in particular C16:1n-7t, warrant further investigation as prognostic markers in HFpEF. Higher blood levels of industrially processed TFA, but not of the naturally occurring TFA C16:1n-7t, are associated with a higher risk cardiometabolic phenotype and prognostic of lower aerobic capacity in patients with HFpEF.

Proposition of an Energy Intake Estimating Scale through Item Response Theory

BACKGROUND

Traditional methods for assessing individual energy consumption often involve lengthy and intricate procedures. This study aims to introduce an Energy Consumption Estimation Scale, utilizing Item Response Theory (IRT) for adolescents aged 18-19 years.

METHODS

This psychometric investigation applies IRT to 93 items extracted from a validated food frequency questionnaire. The study encompasses a representative sample of 2515 adolescents from the São Luís birth cohort in Brazil. The latent trait, energy intake, is derived using IRT and subsequently validated through hierarchical multiple linear regression modeling. Significance was established at p < 0.05.

RESULTS

A Samejima's model was successfully fitted (CFI and TLI > 0.9 and RMSEA < 0.08), effectively capturing variations across all energy consumption levels. Factors associated with the latent trait demonstrate consistent behavioral patterns. Adolescents with higher energy intake exhibited increased consumption of dairy products, artificially sweetened beverages, and seasonal fruits and vegetables.

CONCLUSIONS

The proposed Energy Consumption Estimation Scale demonstrates a reliable measurement of energy intake and serves as a practical and concise alternative for assessing energy consumption among adolescents. These findings suggest the potential for adapting similar models for different age groups and incorporating diverse food items based on the obtained results.

Effect of a pescetarian and vegan diet on fatty acid composition in blood and spermatozoa in young healthy men

INTRODUCTION

There is a growing interest in vegetarian and vegan diets, but both can potentially affect tissue fatty acids (FA) composition. We aimed to evaluate the effect of vegetarian diets on plasma, erythrocytes, and sperm n-3 polyunsaturated fatty acids (n-3 PUFA) status in healthy young men.

METHODS

Four groups were studied: i) men consuming a regular omnivore diet (OMV-1, n = 35); ii) men consuming an omnivore diet but excluding fish and seafood (OMV-2, n = 34); iii) men consuming a pescetarian diet (including dairy, eggs, fish, and seafood) (PESC, n = 36); and iv) men following a strict vegan diet (VEG, n = 35). Participants in each group should follow their diet for at least the previous 12 months. Diet evaluation used a structured validated food frequency questionnaire. FA composition was measured in plasma, erythrocyte phospho-lipids, and spermatozoa by gas-liquid chromatography, expressed as a mole percentage of the total FA content.

RESULTS

Main findings showed higher alpha-linolenic fatty acid (ALA) and total n-3 PUFA dietary intake in the VEG group. In plasma, arachidonic and eicosapentaenoic acids were higher in OMV and PESC groups, whereas docosahexaenoic acid (DHA) level was lower in VEG. Higher ALA, but reduced DHA and total n-3 PUFA levels were found in erythrocytes and spermatozoa in the VEG group.

CONCLUSION

Higher dietary ALA intake was found in pescetarians and vegan men. However, the higher ALA intake was not reflected in higher DHA content in the evaluated tissues. PUFA assessment, with particular emphasis in DHA, are necessary to improve PUFA status in vegan men.

Blended diet for enteral tube feeding in young people: A systematic review of the benefits and complications

BACKGROUND

Interest and use of blended diets (BD) for young people who are tube fed has significantly increased in the last decade, driven primarily by the desires of motivated caregivers. This review identified, appraised and synthesised the available evidence on the benefits and complications of BD versus commercial feeds.

METHODS

A systematic review following PRISMA guidance and registered with PROSPERO was conducted across PubMed, Embase, CINAHL, Scopus and Cochrane up to August 2022.

INCLUSION CRITERIA

English language studies including (1) children, (2) original research (interventional and observational) and (3) examination of BD outcomes. Exclusion criteria were (1) unoriginal research or case reports, (2) focus on feeding management, preparations or attitudes and (3) comparing commercial blends only. Data were synthesised using an established narrative synthesis approach using the Mixed Methods Appraisal Tool.

RESULTS

Eight hundred and six database results were identified and 61 were sought for retrieval. A full-text article review revealed seven eligible studies, involving 267 participants (age range 9 months to 26 years). Studies reported differences in gastrointestinal symptoms (n = 222), medication use (n = 119), growth (n = 189) and complications or adverse events (n = 91). The results indicate positive outcomes, particularly in gastrointestinal symptom control, with few reports of mild adverse events in the included studies.

CONCLUSIONS

There is a paucity of data in this area and much heterogeneity in the included studies, but the available literature points towards positive outcomes. This is an important and highly relevant topic, and more primary research, ideally using standardised reporting, is required to answer the key questions.

Need for a nutrition-specific scientific paradigm for research quality improvement

Nutrition science has been criticised for its methodology, apparently contradictory findings and generating controversy rather than consensus. However, while certain critiques of the field are valid and informative for developing a more cogent science, there are also unique considerations for the study of diet and nutrition that are either overlooked or omitted in these discourses. The ongoing critical discourse on the utility of nutrition sciences occurs at a time when the burden of non-communicable cardiometabolic disease continues to rise in the population. Nutrition science, along with other disciplinary fields, is tasked with producing a translational evidence-base fit for the purpose of improving population and individual health and reducing disease risk. Thus, an exploration of the unique methodological and epistemic considerations for nutrition research is important for nutrition researchers, students and practitioners, to further develop an improved scientific discipline for nutrition. This paper will expand on some of the challenges facing nutrition research, discussing methodological facets of nutritional epidemiology, randomised controlled trials and meta-analysis, and how these considerations may be applied to improve research methodology. A pragmatic research paradigm for nutrition science is also proposed, which places methodology at its centre, allowing for questions over both how we obtain knowledge and research design as the method to produce that knowledge to be connected, providing the field of nutrition research with a framework within which to capture the full complexity of nutrition and diet.

Embracing complexity: making sense of diet, nutrition, obesity and type 2 diabetes

Nutrition therapy has been emphasised for decades for people with type 2 diabetes, and the vital importance of diet and nutrition is now also recognised for type 2 diabetes prevention. However, the complexity of diet and mixed messages on what is unhealthy, healthy or optimal have led to confusion among people with diabetes and their physicians as well as the general public. What should people eat for the prevention, management and remission of type 2 diabetes? Recently, progress has been made in research evidence that has advanced our understanding in several areas of past uncertainty. This article examines some of these issues, focusing on the role of diet in weight management and in the prevention and management of type 2 diabetes. It considers nutritional strategies including low-energy, low-fat and low-carbohydrate diets, discusses inter-relationships between nutrients, foods and dietary patterns, and examines aspects of quantity and quality together with new developments, challenges and future directions.

Lack of compensation of energy intake explains the success of alternate day feeding to produce weight loss

BACKGROUND AND AIMS

This study was designed to obtain daily weighed food intake of participants engaged in Alternate Day Feeding (ADF). Prior ADF studies have used self-reported food intake, a method that has received criticism for its limited accuracy.

SUBJECTS AND METHODS

Forty-nine university students received academic credit for participating in the study. Following a 10-day baseline period, participants underwent ADF for the next 8 days. Restricted daily intake to ∼ 75% of baseline food intake levels was followed by ad libitum intake on alternate days. Food intake was weighed before and after each meal. Daily body weight was also tracked.

INTERVENTION

After the baseline period, participants underwent 8 days of ADF during which they consumed ∼ 75% of baseline energy intake by weight followed by ad libitum intake on alternate days. The trial concluded with 2 additional days of ad libitum feeding, for a total study duration of 10 days.

RESULTS

Daily food intake was constant during the baseline period (slope = -0.93 g/d, p = 0.56), and did not differ significantly (995 g (95% CI [752, 1198]) from the total consumed on ad libitum ADF days (951 g (95% CI [777, 1227]). Intake on ad libitum days did not show a trend to increase during the intervention. Body weight declined significantly during ADF.

CONCLUSIONS

ADF produces significant weight loss because food intake does not increase on ad libitum feeding days to compensate for reduced intake on restricted energy days. Data are consistent with prior work that suggests humans do not fully compensate for imposed deficits in energy intake.

Associations between eating in the absence of hunger and executive functions in adolescents with binge-eating disorder: An experimental study

Eating in the absence of hunger (EAH) is one of the key behavioral features of binge-eating disorder (BED) in youth. Although preliminary evidence revealed that adolescent BED co-occurs with deficits in executive functions (EFs), it is unclear whether EFs are related to EAH. Thus, this study experimentally examined whether deficits in EFs predict EAH in adolescents with and without BED. Adolescents (12-20 years) with BED (n = 28) and age-, sex-, and weight-matched controls (n = 28) underwent an EAH paradigm in the laboratory, where they were offered snacks ad libitum after having established satiety during a lunch meal. Cognitive interference, cognitive flexibility, decision making, and EFs in daily life were assessed by neuropsychological tests and self-report. The BED group showed a significantly higher food intake in gram during the EAH trial than controls with medium effect, but no significant group differences in EFs emerged. Dysfunctional decision making in terms of risky decision making, but no other EFs, predicted increased EAH (g, kcal) in the total sample. Although increases in risky decision making over adolescence are well known, this study uniquely revealed that general decision-making abilities driven by short-term reward may account for disinhibited eating behavior. Interventions targeting decision making with focus on reward sensitivity should be evaluated for their efficacy in preventing and reducing disinhibited eating behavior in adolescents.

[Immunomodulation by nutritional intervention in critically ill patients]

Critically ill patients often suffer from a complex and severe immunological dysfunction. The differentiation and function of human immune cells are fundamentally controlled through metabolic processes. New concepts of immunonutrition therefore try to use enteral and parenteral nutrition to positively impact on the immune function of intensive care unit patients. This review article concisely presents the currently available evidence on the commonly used isolated supplements (anti-oxidative substances, amino acids, essential fatty acids) and difficulties related to their clinical use. The second part presents new and more comprehensive concepts of immunonutrition to influence the intestinal microbiome and to modulate the macronutrient composition. Immunonutrition of critically ill patients bears enormous potential and could become a valuable clinical tool for modulation of the immunometabolism of intensive care unit patients.

The association of dietary and nutrient patterns on neurocognitive decline: A systematic review of MRI and PET studies

BACKGROUND

As the global population ages, there has been a growing incidence of neurodegenerative diseases such as Alzheimer's. More recently, studies exploring the relationship between dietary patterns and neuroimaging outcomes have received particular attention. This systematic literature review provides a structured overview of the association between dietary and nutrient patterns on neuroimaging outcomes and cognitive markers in middle-aged to older adults. A comprehensive literature search was conducted to find relevant articles published from 1999 to date using the following databases Ovid MEDLINE, Embase, PubMed, Scopus and Web of Science. The inclusion criteria for the articles comprised studies reporting on the association between dietary patterns and neuroimaging outcomes, which includes both specific pathological hallmarks of neurodegenerative diseases such as Aβ and tau and nonspecific markers such as structural MRI and glucose metabolism. The risk of bias was evaluated using the Quality Assessment tool from the National Heart, Lung, and Blood Institute of the National Institutes of Health. The results were then organized into a summary of results table, collated based on synthesis without meta-analysis. After conducting the search, 6050 records were extracted and screened for eligibility, with 107 eligible for full-text screening and 42 articles ultimately being included in this review. The results of the systematic review indicate that there is some evidence suggesting that healthy dietary and nutrient patterns were associated with neuroimaging measures, indicative of a protective influence on neurodegeneration and brain ageing. Conversely, unhealthy dietary and nutrient patterns showed evidence pointing to decreased brain volumes, poorer cognition and increased Aβ deposition. Future research should focus on sensitive neuroimaging acquisition and analysis methods, to study early neurodegenerative changes and identify critical periods for interventions and prevention.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no, CRD42020194444).

History of trying exclusion diets and association with avoidant/restrictive food intake disorder in neurogastroenterology patients: A retrospective chart review

BACKGROUND

Exclusion diets for gastrointestinal symptom management have been hypothesized to be a risk factor for avoidant/restrictive food intake disorder (ARFID; a non-body image-based eating disorder). In a retrospective study of pediatric and adult neurogastroenterology patients, we aimed to (1) identify the prevalence and characteristics of an exclusion diet history and (2) evaluate if an exclusion diet history was concurrently associated with the presence of ARFID symptoms.

METHODS

We conducted a chart review of 539 consecutive referrals (ages 6-90, 69% female) to adult (n = 410; January-December 2016) and pediatric (n = 129; January 2016-December 2018) neurogastroenterology clinics. Masked coders (n = 4) retrospectively applied DSM-5 criteria for ARFID and a separate coder assessed documentation of exclusion diet history. We excluded patients with no documentation of diet in the chart (n = 35) or who were not orally fed (n = 9).

RESULTS

Of 495 patients included, 194 (39%) had an exclusion diet history, and 118 (24%) had symptoms of ARFID. Of reported diets, dairy-free was the most frequent (45%), followed by gluten-free (36%). Where documented, exclusion diets were self-initiated by patients/parents in 66% of cases, and recommended by gastroenterology providers in 30%. Exclusion diet history was significantly associated with the presence of ARFID symptoms (OR = 3.12[95% CI 1.92-5.14], p < 0.001).

CONCLUSIONS

History of following an exclusion diet was common and was most often patient-initiated among pediatric and adult neurogastroenterology patients. As patients with self-reported exclusion diet history were over three times as likely to have ARFID symptoms, providers should be cognizant of this potential association when considering dietary interventions.

Association between chili pepper consumption and risk of gastrointestinal-tract cancers: A meta-analysis

Background

Stimulating food is emerging as an important modifiable factor in the development of gastrointestinal (GI) tract cancers, but the association between chili pepper consumption and the risk of GI cancers is unclear. We aimed to evaluate the direction and magnitude of the association between chili pepper consumption and the risk of GI cancers.

Methods

A literature search was performed in PubMed, Embase, and Web of Science databases from inception to 22 December 2021. Observational studies reporting the association between chili pepper consumption and the risk of gastric cancer (GC), esophageal cancer (EC), and/or colorectal cancer (CRC) in adults were eligible for inclusion. Data extraction and quality assessment were conducted independently by two reviewers for the included literature. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using a random-effects model. Subgroup analyses were also performed based on the cancer type, study design, region of the study, study quality, and adjustments.

Results

A total of 11,421 studies were screened, and 14 case-control studies were included involving 5009 GI cancers among 11,310 participants. The summary OR showed that high consumption of chili pepper was positively related to the risk of GI cancers (OR = 1.64; 95% CI: 1.00–2.70). A stronger positive relationship was observed between chili pepper consumption and EC risk (OR = 2.71; 95% CI: 1.54–4.75), but there was no statistically significant association between GC and CRC risk. In analyses stratified by geographical location, a positive association was found between chili pepper consumption and the risk of GI cancers in Asian studies (OR = 2.50; 95% CI: 1.23–5.08), African studies (OR = 1.62; 95% CI: 1.04–2.52), and North American studies (OR = 2.61; 95% CI: 1.34–5.08), but an inverse association was seen in South American studies (OR = 0.50; 95% CI: 0.29–0.87) and European studies (OR = 0.30; 95% CI: 0.15–0.61).

Conclusion

This meta-analysis suggests that chili pepper is a risk factor for certain GI cancers (e.g., EC). Geographical regions influence the risk of GI cancers, especially in Asian, African, and North American populations, which require more attention during dietary guidance.

Systematic review registration

[https://www.crd.york.ac.uk/PROSPERO/], identifier [CRD42022320670].

Reproducibility and Validity of a Semi-Quantitative Food Frequency Questionnaire for Assessing Dietary Intake of Vegetarians and Omnivores in Harbin, China

This study aims to evaluate the reproducibility and validity of a semi-quantitative food frequency questionnaire (SQFFQ) developed for vegetarians and omnivores in Harbin, China. Participants (36 vegetarians and 64 omnivores) administered SQFFQ at baseline (SQFFQ1) and six months later (SQFFQ2) to assess the reproducibility. The 24 h recalls (24 HRs) for three consecutive days were completed between the administrations of two SQFFQs to determine the validity. For reproducibility, Pearson correlation coefficients between SQFFQ1 and SQFFQ2 for vegetarians and omnivores were 0.45~0.88 and 0.44~0.84, respectively. For validity, unadjusted Pearson correlation coefficients were 0.46~0.83 with an average of 0.63 and 0.43~0.86 with an average of 0.61, respectively; energy-adjusted Pearson correlation coefficients were 0.43~0.82 with an average of 0.61 and 0.40~0.85 with an average of 0.59, respectively. Majority of the correlation coefficients for food groups and macronutrients decreased or remained unchanged after energy adjustment. Furthermore, all correlations were statistically significant (p < 0.05). Bland−Altman plots also showed reasonably acceptable agreement between the two methods. In conclusion, the SQFFQ developed in this study has reasonably acceptable reproducibility and validity.

Dose-dependent effect of carbohydrate restriction for type 2 diabetes management: a systematic review and dose-response meta-analysis of randomized controlled trials

BACKGROUND

Carbohydrate restriction is effective for type 2 diabetes management.

OBJECTIVES

We aimed to evaluate the dose-dependent effect of carbohydrate restriction in patients with type 2 diabetes.

METHODS

We systematically searched PubMed, Scopus, and Web of Science to May 2021 for randomized controlled trials evaluating the effect of a carbohydrate-restricted diet (≤45% total calories) in patients with type 2 diabetes. The primary outcome was glycated hemoglobin (HbA1c). Secondary outcomes included fasting plasma glucose (FPG); body weight; serum total, LDL, and HDL cholesterol; triglyceride (TG); and systolic blood pressure (SBP). We performed random-effects dose-response meta-analyses to estimate mean differences (MDs) for a 10% decrease in carbohydrate intake.

RESULTS

Fifty trials with 4291 patients were identified. At 6 months, compared with a carbohydrate intake between 55%-65% and through a maximum reduction down to 10%, each 10% reduction in carbohydrate intake reduced HbA1c (MD, -0.20%; 95% CI, -0.27% to -0.13%), FPG (MD, -0.34 mmol/L; 95% CI, -0.56 to -0.12 mmol/L), and body weight (MD, -1.44 kg; 95% CI, -1.82 to -1.06 kg). There were also reductions in total cholesterol, LDL cholesterol, TG, and SBP. Levels of HbA1c, FPG, body weight, TG, and SBP decreased linearly with the decrease in carbohydrate intake from 65% to 10%. A U-shaped effect was seen for total cholesterol and LDL cholesterol, with the greatest reduction at 40%. At 12 months, a linear reduction was seen for HbA1c and TG. A U-shaped effect was seen for body weight, with the greatest reduction at 35%.

CONCLUSIONS

Carbohydrate restriction can exert a significant and important reduction on levels of cardiometabolic risk factors in patients with type 2 diabetes. Levels of most cardiometabolic outcomes decreased linearly with the decrease in carbohydrate intake. U-shaped effects were seen for total cholesterol and LDL cholesterol at 6 months and for body weight at 12 months.

Effect of High-intensity Training and Probiotics on Gut Microbiota Diversity in Competitive Swimmers: Randomized Controlled Trial

BACKGROUND

Physical exercise has favorable effects on the structure of gut microbiota and metabolite production in sedentary subjects. However, little is known whether adjustments in an athletic program impact overall changes of gut microbiome in high-level athletes. We therefore characterized fecal microbiota and serum metabolites in response to a 7-week, high-intensity training program and consumption of probiotic Bryndza cheese.

METHODS

Fecal and blood samples and training logs were collected from young competitive male (n = 17) and female (n = 7) swimmers. Fecal microbiota were categorized using specific primers targeting the V1-V3 region of 16S rDNA, and serum metabolites were characterized by NMR-spectroscopic analysis and by multivariate statistical analysis, Spearman rank correlations, and Random Forest models.

RESULTS

We found higher α-diversity, represented by the Shannon index value (HITB-pre 5.9 [± 0.4]; HITB-post 6.4 [± 0.4], p = 0.007), (HIT-pre 5.5 [± 0.6]; HIT-post 5.9 [± 0.6], p = 0.015), after the end of the training program in both groups independently of Bryndza cheese consumption. However, Lactococcus spp. increased in both groups, with a higher effect in the Bryndza cheese consumers (HITB-pre 0.0021 [± 0.0055]; HITB-post 0.0268 [± 0.0542], p = 0.008), (HIT-pre 0.0014 [± 0.0036]; HIT-post 0.0068 [± 0.0095], p = 0.046). Concomitant with the increase of high-intensity exercise and the resulting increase of anaerobic metabolism proportion, pyruvate (p[HITB] = 0.003; p[HIT] = 0.000) and lactate (p[HITB] = 0.000; p[HIT] = 0.030) increased, whereas acetate (p[HITB] = 0.000; p[HIT] = 0.002) and butyrate (p[HITB] = 0.091; p[HIT] = 0.019) significantly decreased.

CONCLUSIONS

Together, these data demonstrate a significant effect of high-intensity training (HIT) on both gut microbiota composition and serum energy metabolites. Thus, the combination of intensive athletic training with the use of natural probiotics is beneficial because of the increase in the relative abundance of lactic acid bacteria.

Impact of Maternal Health Behaviours and Social Conditions on Infant Diet at Age 1-Year: Results from a Prospective Indigenous Birth Cohort in Ontario, Canada

Background: Understanding the impact of maternal health behaviours and social conditions on childhood nutrition is important to inform strategies to promote health during childhood. Objective: To describe how maternal health sociodemographic factors (e.g., socioeconomic status, education), health behaviours (e.g., diet), and traditional health care use during pregnancy impact infant diet at age 1-year. Methods: Data were collected from the Indigenous Birth Cohort (ABC) study, a prospective birth cohort formed in partnership with an Indigenous community-based Birthing Centre in southwestern Ontario, Canada. 110 mother-infant dyads are included in the study and were enrolled between 2012 and 2017. Multiple linear regression analyses were performed to understand factors associated with infant diet scores at age 1-year, with a higher score indicating a diet with more healthy foods. Results: The mean age of women enrolled during pregnancy was 27.3 (5.9) years. Eighty percent of mothers had low or moderate social disadvantage, 47.3% completed more than high school education, and 70% were cared for by a midwife during their pregnancy. The pre-pregnancy body mass index (BMI) was <25 in 34.5% of women, 15.5% of mothers smoked during pregnancy, and 14.5% of mothers had gestational diabetes. Being cared for by an Indigenous midwife was associated with a 0.9-point higher infant diet score (p = 0.001) at age 1-year, and lower maternal social disadvantage was associated with a 0.17-point higher infant diet quality score (p = 0.04). Conclusion: This study highlights the positive impact of health care provision by Indigenous midwives and confirms that higher maternal social advantage has a positive impact on child nutrition.

Attenuation of Post-Exercise Energy Intake Following 12 Weeks of Sprint Interval Training in Men and Women with Overweight

An acute bout of sprint interval training (SIT) performed with psychological need-support incorporating autonomy, competence, and relatedness has been shown to attenuate energy intake at the post-exercise meal, but the long-term effects are not known. The aim of this trial was to investigate the effects of 12 weeks of SIT combined with need-support on post-exercise food consumption. Thirty-six physically inactive participants with overweight and obesity (BMI: 29.6 ± 3.8 kg·m−2; V˙O2peak 20.8 ± 4.1 mL·kg−1·min−1) completed three sessions per week of SIT (alternating cycling for 15 s at 170% V˙O2peak and 60 s at 32% V˙O2peak) with need-support or traditional moderate-intensity continuous training (MICT) without need-support (continuous cycling at 60% V˙O2peak). Assessments of appetite, appetite-related hormones, and ad libitum energy intake in response to acute exercise were conducted pre- and post-intervention. Fasting appetite and blood concentrations of active ghrelin, leptin, and insulin did not significantly differ between groups or following the training. Post-exercise energy intake from snacks decreased significantly from pre- (807 ± 550 kJ) to post- SIT (422 ± 468 kJ; p < 0.05) but remained unaltered following MICT. SIT with psychological need-support appears well-tolerated in a physically inactive population with overweight and offers an alternative to traditional exercise prescription where dietary intake is of concern.

Obese individuals do not underreport dietary intake to a greater extent than nonobese individuals when data are allometrically‐scaled

Objective

The aim of this study was to assess the extent of misreporting in obese and nonobese adults on an absolute, ratio‐scaled, and allometrically‐scaled basis.

Method

Self‐reported daily energy intake (EI) was compared with total energy expenditure (TEE) in 221 adults (106 male, 115 female; age 53 ± 17 years, stature 1.68 ± 0.09 m, mass 79.8 ± 17.2 kg) who participated in a doubly‐labeled water (DLW) subsection of 2013–2015 National Diet and Nutrition Survey. Data were log transformed and expressed as absolute values, according to simple ratio‐standards (per kg body mass) and adjusted for body mass allometrically. Absolute and ratio‐scaled misreporting were examined using full‐factorial General Linear Models with repeated measures of the natural logarithms of TEE or EI as the within‐subjects factor. The natural logarithm of body mass was included as a covariate in the allometric method. The categorical variables of gender, age, obesity, and physical activity level (PAL) were the between‐factor variables.

Results

On an absolute‐basis, self‐reported EI (2759 ± 590 kcal·d⁻¹) was significantly lower than TEE measured by DLW (2759 ± 590 kcal·d⁻¹: F_1,205 = 598.81, p < .001, η_p² =0.75). We identified significantly greater underreporting in individuals with an obese BMI (F_1,205 = 29.01, p <.001, η_p² =0.12), in more active individuals (PAL > 1.75; F_1,205 = 34.15, p <.001, η_p² =0.14) and in younger individuals (≤55 years; F_1,205 = 14.82, p < .001, η_p² =0.07), which are all categories with higher energy needs. Ratio‐scaling data reduced the effect sizes. Allometric‐scaling removed the effect of body mass (F_1,205 =0.02, p = 0.887, η_p² =0.00).

Conclusion

In weight‐stable adults, obese individuals do not underreport dietary intake to a greater extent than nonobese individuals. These results contradict previous research demonstrating that obesity is associated with a greater degree of underreporting.

Oligofructose-Enriched Inulin Intake, Gut Microbiome Characteristics, and the V̇O2 Peak Response to High-Intensity Interval Training in Healthy Inactive Adults

BACKGROUND

The gut microbiome has been associated with cardiorespiratory fitness.

OBJECTIVES

To assess the effects of oligofructose (FOS)-enriched inulin supplementation on the gut microbiome and the peak oxygen uptake (V̇O2peak) response to high-intensity interval training (HIIT).

METHODS

The study was a randomized controlled trial. Forty sedentary and apparently healthy adults [n = 31 women; aged 31.8 ± 9.8 y, BMI (in kg⋅m-2) 25.9 ± 4.3] were randomly allocated to 1) 6 wk of supervised HIIT (4 × 4-min bouts at 85-95% peak heart rate, interspersed with 3 min of active recovery, 3·wk-1) + 12 g·d-1 of FOS-enriched inulin (HIIT-I) or 2) 6 wk of supervised HIIT (3·wk-1, 4 × 4-min bouts) + 12 g·d-1 of maltodextrin/placebo (HIIT-P). Each participant completed an incremental treadmill test to assess V̇O2peak and ventilatory thresholds (VTs), provided a stool and blood sample, and completed a 24-h diet recall questionnaire and FFQ before and after the intervention. Gut microbiome analyses were performed using metagenomic sequencing. Fecal short-chain fatty acids were measured by mass spectrometry.

RESULTS

There were no differences in the mean change in V̇O2peak response between groups (P = 0.58). HIIT-I had a greater improvement in VTs than HIIT-P [VT1 (lactate accumulation): mean difference + 4.3% and VT2 (lactate threshold): +4.2%, P < 0.05]. HIIT-I had a greater increase in the abundance of Bifidobacterium taxa [false discovery rate (FDR) < 0.05] and several metabolic processes related to exercise capacity (FDR < 0.05). Exploratory analysis of merged data found participants with a greater response to HIIT (V̇O2peak ≥3.5 mL⋅kg-1⋅min-1) had a 2.2-fold greater mean abundance of gellan degradation pathways (FDR < 0.05) and a greater, but not significant, abundance of Bifidobacterium uniformis species (P < 0.00023, FDR = 0.08).

CONCLUSIONS

FOS-enriched inulin supplementation did not potentiate HIIT-induced improvements in V̇O2peak but led to gut microbiome changes possibly associated with greater ventilatory threshold improvements in healthy inactive adults. Gellan degradation pathways and B. uniformis spp. were associated with greater V̇O2peak responses to HIIT.

Reduced n-3 and n-6 PUFA (DHA and AA) Concentrations in Breast Milk and Erythrocytes Phospholipids during Pregnancy and Lactation in Women with Obesity

Obesity during pregnancy is a worrying public health problem worldwide. Maternal diet is critical for fatty acid (FA) placental transport and FA content in breast milk (BM). We evaluated FA composition in erythrocytes phospholipids (EP) and BM in pregnant women with (OBE, n = 30) and without (non-OBE, n = 31) obesity. Sixty-one healthy women were evaluated at their 20-24th gestational week and followed until 6th month of lactation. Diet was evaluated through a food frequency questionnaire. FA composition of EP and BM was assessed by gas-liquid chromatography. The OBE group showed lower diet quality, but total n-6 and n-3 polyunsaturated FA (PUFA), ALA, EPA, and DHA dietary intake was similar between groups. N-3 PUFA, ALA, DHA, and the n-6/n-3 PUFA ratio in EP were lower at the 6th lactation month in the OBE group. In BM, the arachidonic acid (AA) concentration was lower at the end of the lactation, and DHA content showed an earlier and constant decline in the OBE group compared to the non-OBE group. In conclusion, n-3 PUFA and AA and DHA levels were reduced in EP and BM in pregnant women with obesity. Strategies to increase n-3 PUFA are urgently needed during pregnancy and lactation, particularly in women with obesity.

Memory and eating: A bidirectional relationship implicated in obesity

This paper reviews evidence demonstrating a bidirectional relationship between memory and eating in humans and rodents. In humans, amnesia is associated with impaired processing of hunger and satiety cues, disrupted memory of recent meals, and overconsumption. In healthy participants, meal-related memory limits subsequent ingestive behavior and obesity is associated with impaired memory and disturbances in the hippocampus. Evidence from rodents suggests that dorsal hippocampal neural activity contributes to the ability of meal-related memory to control future intake, that endocrine and neuropeptide systems act in the ventral hippocampus to provide cues regarding energy status and regulate learned aspects of eating, and that consumption of hypercaloric diets and obesity disrupt these processes. Collectively, this evidence indicates that diet-induced obesity may be caused and/or maintained, at least in part, by a vicious cycle wherein excess intake disrupts hippocampal functioning, which further increases intake. This perspective may advance our understanding of how the brain controls eating, the neural mechanisms that contribute to eating-related disorders, and identify how to treat diet-induced obesity.

A Role for Data Science in Precision Nutrition and Early Brain Development

Multimodal brain magnetic resonance imaging (MRI) can provide biomarkers of early influences on neurodevelopment such as nutrition, environmental and genetic factors. As the exposure to early influences can be separated from neurodevelopmental outcomes by many months or years, MRI markers can serve as an important intermediate outcome in multivariate analyses of neurodevelopmental determinants. Key to the success of such work are recent advances in data science as well as the growth of relevant data resources. Multimodal MRI assessment of neurodevelopment can be supplemented with other biomarkers of neurodevelopment such as electroencephalograms, magnetoencephalogram, and non-imaging biomarkers. This review focuses on how maternal nutrition impacts infant brain development, with three purposes: (1) to summarize the current knowledge about how nutrition in stages of pregnancy and breastfeeding impact infant brain development; (2) to discuss multimodal MRI and other measures of early neurodevelopment; and (3) to discuss potential opportunities for data science and artificial intelligence to advance precision nutrition. We hope this review can facilitate the collaborative march toward precision nutrition during pregnancy and the first year of life.

Assessments of risk of bias in systematic reviews of observational nutritional epidemiologic studies are often not appropriate or comprehensive: a methodological study

BACKGROUND

An essential component of systematic reviews is the assessment of risk of bias. To date, there has been no investigation of how reviews of non-randomised studies of nutritional exposures (called 'nutritional epidemiologic studies') assess risk of bias.

OBJECTIVE

To describe methods for the assessment of risk of bias in reviews of nutritional epidemiologic studies.

METHODS

We searched MEDLINE, EMBASE and the Cochrane Database of Systematic Reviews (Jan 2018-Aug 2019) and sampled 150 systematic reviews of nutritional epidemiologic studies.

RESULTS

Most reviews (n=131/150; 87.3%) attempted to assess risk of bias. Commonly used tools neglected to address all important sources of bias, such as selective reporting (n=25/28; 89.3%), and frequently included constructs unrelated to risk of bias, such as reporting (n=14/28; 50.0%). Most reviews (n=66/101; 65.3%) did not incorporate risk of bias in the synthesis. While more than half of reviews considered biases due to confounding and misclassification of the exposure in their interpretation of findings, other biases, such as selective reporting, were rarely considered (n=1/150; 0.7%).

CONCLUSION

Reviews of nutritional epidemiologic studies have important limitations in their assessment of risk of bias.

Repeated exposure to epigallocatechin gallate solution or water alters bitterness intensity and salivary protein profile

Polyphenols, bitter and astringent compounds present in many healthy foods, induce varied sensory responses across individuals. These differences in liking and flavor intensity may be attributable, in part, to differences in saliva. In the current study, we tested the effect of repeated consumption of a bitter polyphenol (epigallocatechin gallate, EGCG) solution on perceived bitterness intensity and salivary protein composition. We hypothesized exposure to EGCG would cause an increase in concentrations of salivary proteins that inhibit bitterness of polyphenols. We also hypothesized that participants with higher habitual polyphenol, specifically the flavanols, intake would experience less bitterness from EGCG solutions than those with low habitual intake, and that the high flavanol consumers would be more resistant to salivary alterations. We also tested whether bovine milk casein, a food analog for salivary proteins that may suppress bitterness, would decrease bitterness intensity of the EGCG solution and mitigate effects of the intervention. Participants (N = 37) in our crossover intervention adhered to two-week periods of daily bitter (EGCG) or control (water) solution consumption. Bitterness intensity ratings and citric acid-stimulated saliva were collected at baseline and after each exposure period. Results indicate that bitterness intensity of the EGCG solution decreased after polyphenol (bitter EGCG) exposure compared to control (water) exposure. Casein addition also decreased bitterness intensity of the EGCG solution. While there was not a significant overall main effect of baseline flavanol intake on solution bitterness, there was an interaction between intervention week and baseline flavanol intake. Surprisingly, the higher flavanol intake group rated EGCG solutions as more bitter than the low and medium intake groups. Of proteins relevant to taste perception, several cystatins changed in saliva in response to the intervention. Interestingly, most of these protein alterations occurred more robustly after the control (water) exposure rather than the bitter (EGCG) exposure, suggesting that additional factors not quantified in this work may influence salivary proteins. Thus, we confirm in this study that exposure to bitterness suppresses ratings of bitterness over time, but more work needs to establish the causal factors of how diet influences salivary proteins.

α1-Acid Glycoprotein and Dietary Intake in End-Stage Renal Disease Patients

Management of end-stage renal disease (ESRD) patients requires monitoring each of the components of malnutrition–inflammation–atherosclerosis (MIA) syndrome. Restrictive diet can negatively affect nutritional status and inflammation. An acute-phase protein—α₁-acid glycoprotein (AGP), has been associated with energy metabolism in animal and human studies. The aim of our study was to look for a relationship between serum AGP concentrations, laboratory parameters, and nutrient intake in ESRD patients. The study included 59 patients treated with maintenance hemodialysis. A 24 h recall assessed dietary intake during four non-consecutive days—two days in the post-summer period, and two post-winter. Selected laboratory tests were performed: complete blood count, serum iron, total iron biding capacity (TIBC) and unsaturated iron biding capacity (UIBC), vitamin D, AGP, C-reactive protein (CRP), albumin, prealbumin, and phosphate–calcium metabolism markers (intact parathyroid hormone, calcium, phosphate). Recorded dietary intake was highly deficient. A majority of patients did not meet recommended daily requirements for energy, protein, fiber, iron, magnesium, folate, and vitamin D. AGP correlated positively with CRP (R = 0.66), platelets (R = 0.29), and negatively with iron (R = −0.27) and TIBC (R = −0.30). AGP correlated negatively with the dietary intake of plant protein (R = −0.40), potassium (R = −0.27), copper (R = −0.30), vitamin B₆ (R = −0.27), and folates (R = −0.27), p < 0.05. However, in multiple regression adjusted for confounders, only CRP was significantly associated with AGP. Our results indicate that in hemodialyzed patients, serum AGP is weakly associated with dietary intake of several nutrients, including plant protein.

Dietary Patterns, Eating Behavior, and Nutrient Intakes of Spanish Preschool Children with Autism Spectrum Disorders

Eating behavior problems are characteristic of children with autism spectrum disorders (ASD) with a highly restricted range of food choices, which may pose an associated risk of nutritional problems. Hence, detailed knowledge of the dietary patterns (DPs) and nutrient intakes of ASD patients is necessary to carry out intervention strategies if required. The present study aimed to determine the DPs and macro-and micronutrient intakes in a sample of Spanish preschool children with ASD compared to typically developing control children. Fifty-four children with ASD (two to six years of age) diagnosed with ASD according to the Diagnostic Manual-5 criteria), and a control group of 57 typically developing children of similar ages were recruited. A validated food frequency questionnaire was used, and the intake of energy and nutrients was estimated through three non-consecutive 24-h dietary registrations. DPs were assessed using principal component analysis and hierarchical clustering analysis. Children with ASD exhibited a DP characterized by high energy and fat intakes and a low intake of vegetables and fruits. Likewise, meat intake of any type, both lean and fatty, was associated with higher consumption of fish and dietary fat. Furthermore, the increased consumption of dairy products was associated with increased consumption of cereals and pasta. In addition, they had frequent consumption of manufactured products with poor nutritional quality, e.g., beverages, sweets, snacks and bakery products. The percentages of children with ASD complying with the adequacy of nutrient intakes were higher for energy, saturated fat, calcium, and vitamin C, and lower for iron, iodine, and vitamins of group B when compared with control children. In conclusion, this study emphasizes the need to assess the DPs and nutrient intakes of children with ASD to correct their alterations and discard some potential nutritional diseases.

Meat and mental health: A meta-analysis of meat consumption, depression, and anxiety

In this meta-analysis, we examined the quantitative relation between meat consumption or avoidance, depression, and anxiety. In June 2020, we searched five online databases for primary studies examining differences in depression and anxiety between meat abstainers and meat consumers that offered a clear (dichotomous) distinction between these groups. Twenty studies met the selection criteria representing 171,802 participants with 157,778 meat consumers and 13,259 meat abstainers. We calculated the magnitude of the effect between meat consumers and meat abstainers with bias correction (Hedges's g effect size) where higher and positive scores reflect better outcomes for meat consumers. Meat consumption was associated with lower depression (Hedges's g = 0.216, 95% CI [0.14 to 0.30], p < .001) and lower anxiety (g = 0.17, 95% CI [0.03 to 0.31], p = .02) compared to meat abstention. Compared to vegans, meat consumers experienced both lower depression (g = 0.26, 95% CI [0.01 to 0.51], p = .041) and anxiety (g = 0.15, 95% CI [-0.40 to 0.69], p = .598). Sex did not modify these relations. Study quality explained 58% and 76% of between-studies heterogeneity in depression and anxiety, respectively. The analysis also showed that the more rigorous the study, the more positive and consistent the relation between meat consumption and better mental health. The current body of evidence precludes causal and temporal inferences.

[Saturated fatty acids and cardiovascular risk : Is a revision of the recommendations on nutrition indicated?]

Die „Fetthypothese der koronaren Herzkrankheit“, derzufolge „gesättigte Fettsäuren“ („saturated fatty acids“, SFA) die LDL(„low-density lipoprotein“)-Cholesterin-Konzentration (LDL-C) steigern und folglich das Risiko für kardiovaskuläre Erkrankungen erhöhen, prägte die Ernährungsempfehlungen der letzten 60 Jahre, zunächst in den USA und später auch in Europa. Über die Jahre mehrte sich Evidenz aus Epidemiologie und kontrollierten klinischen Studien, dass der Konsum von SFA per se nicht mit einem erhöhten kardiovaskulären Risiko einhergeht bzw. die Einschränkung des Konsums von SFA keine präventive Wirkung zeigt. Die Fokussierung auf den SFA-Gehalt negiert die biologisch heterogenen und zum Teil biologisch günstigen Wirkungen unterschiedlicher SFA. Zudem wird hierbei außer Acht gelassen, dass SFA in intakten Lebensmitteln in unterschiedliche komplexe Matrizes eingebunden sind, die aus Dutzenden Nährstoffen mit unterschiedlicher Struktur und Begleitstoffen bestehen und damit jeweils unterschiedliche biologische Antworten und metabolische Effekte auslösen. Entsprechend sind solche nährstoffbasierten Empfehlungen prinzipiell wenig zielführend und zudem schlecht umsetzbar. Hinzu kommt, dass LDL‑C kein geeigneter Marker ist, um den Effekt von Lebensstilintervention wie der Ernährung oder aber der körperlichen Aktivität auf das globale kardiovaskuläre Risiko zu beurteilen.

Eating behavior as a new frontier in memory research

The study of memory is commonly associated with neuroscience, aging, education, and eyewitness testimony. Here we discuss how eating behavior is also heavily intertwined-and yet considerably understudied in its relation to memory processes. Both are influenced by similar neuroendocrine signals (e.g., leptin and ghrelin) and are dependent on hippocampal functions. While learning processes have long been implicated in influencing eating behavior, recent research has shown how memory of recent eating modulates future consumption. In humans, obesity is associated with impaired memory performance, and in rodents, dietary-induced obesity causes rapid decrements to memory. Lesions to the hippocampus disrupt memory but also induce obesity, highlighting a cyclic relationship between obesity and memory impairment. Enhancing memory of eating has been shown to reduce future eating and yet, little is known about what influences memory of eating or how memory of eating differs from memory for other behaviors. We discuss recent advancements in these areas and highlight fruitful research pursuits afforded by combining the study of memory with the study of eating behavior.

Derivation and Validation of a Total Fruit and Vegetable Intake Prediction Model to Identify Targets for Biomarker Discovery Using the UK National Diet and Nutrition Survey

BACKGROUND

Dietary assessments in research and clinical settings are largely reliant on self-reported questionnaires. It is acknowledged that these are subject to measurement error and biases and that objective approaches would be beneficial. Dietary biomarkers have been purported as a complementary approach to improve the accuracy of dietary assessments. Tentative biomarkers have been identified for many individual fruits and vegetables (FVs), but an objective total FV intake assessment tool has not been established.

OBJECTIVES

To derive and validate a prediction model of total FV intake (TFVpred) to inform future biomarker studies.

METHODS

Data from the National Diet and Nutrition Survey (NDNS) were used for this analysis. A modeling group (MG) consisting of participants aged >11 years from the NDNS years 5-6 was created (n = 1746). Intake data for 96 FVs were analyzed by stepwise regression to derive a model that satisfied 3 selection criteria: SEE ≤80, R2 >0.7, and ≤10 predictors. The TFVpred model was validated using comparative data from a validation group (VG) created from the NDNS years 7-8 (n = 1865). Pearson's correlation coefficients were assessed between observed and predicted values in the MG and VG. Bland-Altman plots were used to assess agreement between TFVpred estimates and total FV intake.

RESULTS

A TFVpred model, comprised of tomatoes, apples, carrots, bananas, pears, strawberries, and onions, satisfied the selection criteria (R2 = 0.761; SEE = 78.81). Observed and predicted total FV intake values were positively correlated in the MG (r = 0.872; P < 0.001; R2 = 0.761) and the VG (r = 0.838; P < 0.001; R2 = 0.702). In the MG and VG, 95.0% and 94.9%, respectively, of TFVpred model residuals were within the limits of agreement.

CONCLUSIONS

Intakes of a concise FV list can be used to predict total FV intakes in a UK population. The individual FVs included in the TFVpred model present targets for biomarker discovery aimed at objectively assessing total FV intake.

A healthy Nordic diet score and risk of incident CHD among men: the Kuopio Ischaemic Heart Disease Risk Factor Study

Healthy Nordic diet has been beneficially associated with CHD risk factors, but few studies have investigated risk of developing CHD. We investigated the associations of healthy Nordic diet with major CHD risk factors, carotid atherosclerosis and incident CHD in middle-aged and older men from eastern Finland. A total of 1981 men aged 42-60 years and free of CHD at baseline in 1984-1989 were investigated. Diet was assessed with 4-d food recording and the healthy Nordic diet score was calculated based on the Baltic Sea Diet Score. Carotid atherosclerosis was assessed by ultrasonography of the common carotid artery intima-media thickness in 1053 men. ANCOVA and Cox proportional hazards regression analyses were used for analyses. Healthy Nordic diet score was associated with lower serum C-reactive protein (CRP) concentrations (multivariable-adjusted extreme-quartile difference 0·66 mg/l, 95 % CI 0·11, 1·21 mg/l) but not with serum lipid concentrations, blood pressure or carotid atherosclerosis. During the average follow-up of 21·6 years (sd 8·3 years), 407 men had a CHD event, of which 277 were fatal. The multivariable-adjusted hazard ratios in the lowest v. the highest quartile of the healthy Nordic diet score were 1·15 (95 % CI 0·87, 1·51) for any CHD event (Ptrend 0·361) and 1·44 (95 % CI 0·99, 2·08) (Ptrend 0·087) for fatal CHD event. We did not find evidence that adherence to a healthy Nordic diet would be associated with a lower risk of CHD or with carotid atherosclerosis or major CHD risk factors, except for an inverse association with serum CRP concentrations.

The associations between maternal and child diet quality and child ADHD - findings from a large Norwegian pregnancy cohort study

BACKGROUND

Attention Deficit Hyperactivity Disorder (ADHD) is a prevalent neurodevelopmental disorder. Effective long-term treatment options are limited, which warrants increased focus on potential modifiable risk factors. The aim of this study was to investigate associations between maternal diet quality during pregnancy and child diet quality and child ADHD symptoms and ADHD diagnosis.

METHODS

This study is based on the Norwegian Mother, Father and Child Cohort Study (MoBa). We assessed maternal diet quality with the Prenatal Diet Quality Index (PDQI) and Ultra-Processed Food Index (UPFI) around mid-gestation, and child diet quality using the Diet Quality Index (CDQI) at 3 years. ADHD symptoms were assessed at child age 8 years using the Parent Rating Scale for Disruptive Behaviour Disorders. ADHD diagnoses were retrieved from the Norwegian Patient Registry.

RESULTS

In total, 77,768 mother-child pairs were eligible for studying ADHD diagnoses and 37,787 for ADHD symptoms. Means (SD) for the PDQI, UPFI and CDQI were 83.1 (9.3), 31.8 (9.7) and 60.3 (10.6), respectively. Mean (SD) ADHD symptom score was 8.4 (7.1) and ADHD diagnosis prevalence was 2.9% (male to female ratio 2.6:1). For one SD increase in maternal diet index scores, we saw a change in mean (percent) ADHD symptom score of - 0.28 (- 3.3%) (CI: - 0.41, - 0.14 (- 4.8, - 1.6%)) for PDQI scores and 0.25 (+ 3.0%) (CI: 0.13, 0.38 (1.5, 4.5%)) for UPFI scores. A one SD increase in PDQI score was associated with a relative risk of ADHD diagnosis of 0.87 (CI: 0.79, 0.97). We found no reliable associations with either outcomes for the CDQI, and no reliable change in risk of ADHD diagnosis for the UPFI.

CONCLUSIONS

We provide evidence that overall maternal diet quality during pregnancy is associated with a small decrease in ADHD symptom score at 8 years and lower risk for ADHD diagnosis, with more robust findings for the latter outcome. Consumption of ultra-processed foods was only associated with increased ADHD symptom score of similar magnitude as for overall maternal diet quality, and we found no associations between child diet quality and either outcome. No causal inferences should be made based on these results, due to potential unmeasured confounding.

The carbon isotope ratios of nonessential amino acids identify sugar-sweetened beverage (SSB) consumers in a 12-wk inpatient feeding study of 32 men with varying SSB and meat exposures

BACKGROUND

The carbon isotope ratios (CIRs) of individual amino acids (AAs) may provide more sensitive and specific biomarkers of sugar-sweetened beverages (SSBs) than total tissue CIR. Because CIRs turn over slowly, long-term controlled-feeding studies are needed in their evaluation.

OBJECTIVE

We assessed the responses of plasma and RBC CIRAA's to SSB and meat intake in a 12-wk inpatient feeding study.

METHODS

Thirty-two men (aged 46.2 ± 10.5 y) completed the feeding study at the National Institute of Diabetes and Digestive and Kidney Diseases in Phoenix, Arizona. The effects of SSB, meat, and fish intake on plasma and RBC CIRAA's were evaluated in a balanced factorial design with each dietary variable either present or absent in a common weight-maintaining, macronutrient-balanced diet. Fasting blood samples were collected biweekly from baseline. Dietary effects on the postfeeding CIR of 5 nonessential AAs (CIRNEAA's) and 4 essential AAs (CIREAA's) were analyzed using multivariable regression.

RESULTS

In plasma, 4 of 5 CIRNEAA's increased with SSB intake. Of these, the CIRAla was the most sensitive (β = 2.81, SE = 0.38) to SSB intake and was not affected by meat or fish intake. In RBCs, all 5 CIRNEAA's increased with SSBs but had smaller effect sizes than in plasma. All plasma CIREAA's increased with meat intake (but not SSB or fish intake), and the CIRLeu was the most sensitive (β = 1.26, SE = 0.23). CIRs of leucine and valine also increased with meat intake in RBCs. Estimates of turnover suggest that CIRAA's in plasma, but not RBCs, were in equilibrium with the diets by the end of the study.

CONCLUSIONS

The results of this study in men support CIRNEAA's as potential biomarkers of SSB intake and suggest CIREAA's as potential biomarkers of meat intake in US diets. This trial was registered at clinicaltrials.gov/ct2/show/NCT01237093 as NCT01237093.

Efficacy and safety of low and very low carbohydrate diets for type 2 diabetes remission: systematic review and meta-analysis of published and unpublished randomized trial data

OBJECTIVE

To determine the efficacy and safety of low carbohydrate diets (LCDs) and very low carbohydrate diets (VLCDs) for people with type 2 diabetes.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Searches of CENTRAL, Medline, Embase, CINAHL, CAB, and grey literature sources from inception to 25 August 2020.

STUDY SELECTION

Randomized clinical trials evaluating LCDs (<130 g/day or <26% of a 2000 kcal/day diet) and VLCDs (<10% calories from carbohydrates) for at least 12 weeks in adults with type 2 diabetes were eligible.

DATA EXTRACTION

Primary outcomes were remission of diabetes (HbA1c <6.5% or fasting glucose <7.0 mmol/L, with or without the use of diabetes medication), weight loss, HbA1c, fasting glucose, and adverse events. Secondary outcomes included health related quality of life and biochemical laboratory data. All articles and outcomes were independently screened, extracted, and assessed for risk of bias and GRADE certainty of evidence at six and 12 month follow-up. Risk estimates and 95% confidence intervals were calculated using random effects meta-analysis. Outcomes were assessed according to a priori determined minimal important differences to determine clinical importance, and heterogeneity was investigated on the basis of risk of bias and seven a priori subgroups. Any subgroup effects with a statistically significant test of interaction were subjected to a five point credibility checklist.

RESULTS

Searches identified 14 759 citations yielding 23 trials (1357 participants), and 40.6% of outcomes were judged to be at low risk of bias. At six months, compared with control diets, LCDs achieved higher rates of diabetes remission (defined as HbA1c <6.5%) (76/133 (57%) v 41/131 (31%); risk difference 0.32, 95% confidence interval 0.17 to 0.47; 8 studies, n=264, I2=58%). Conversely, smaller, non-significant effect sizes occurred when a remission definition of HbA1c <6.5% without medication was used. Subgroup assessments determined as meeting credibility criteria indicated that remission with LCDs markedly decreased in studies that included patients using insulin. At 12 months, data on remission were sparse, ranging from a small effect to a trivial increased risk of diabetes. Large clinically important improvements were seen in weight loss, triglycerides, and insulin sensitivity at six months, which diminished at 12 months. On the basis of subgroup assessments deemed credible, VLCDs were less effective than less restrictive LCDs for weight loss at six months. However, this effect was explained by diet adherence. That is, among highly adherent patients on VLCDs, a clinically important reduction in weight was seen compared with studies with less adherent patients on VLCDs. Participants experienced no significant difference in quality of life at six months but did experience clinically important, but not statistically significant, worsening of quality of life and low density lipoprotein cholesterol at 12 months. Otherwise, no significant or clinically important between group differences were found in terms of adverse events or blood lipids at six and 12 months.

CONCLUSIONS

On the basis of moderate to low certainty evidence, patients adhering to an LCD for six months may experience remission of diabetes without adverse consequences. Limitations include continued debate around what constitutes remission of diabetes, as well as the efficacy, safety, and dietary satisfaction of longer term LCDs.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42020161795.

Self-Selection Bias: An Essential Design Consideration for Nutrition Trials in Healthy Populations

Many researchers have identified the issue of self-selection bias hindering the ability to detect nutrient effects in healthy populations. However, it appears that no effort has been made to mitigate this potential design flaw. By recruiting individuals on the basis of pre-trial dietary intake, the Memory and Attention Supplementation Trial aimed to capture a cohort of participants with a wide variety of dietary intake, thus increasing the likelihood of a diverse range of nutrient status. This perspective specifically examines the profile of these trial volunteers and in doing so, we present the first empirical evidence of self-selection bias when recruiting healthy volunteers for a randomized controlled trial of a nutrient-based supplement. These findings support the anecdotal proposal that traditional recruitment methods inherently attract trial volunteers who are vastly unrepresentative of the population and threatens the generalizability of this field of research. Alternative approaches to recruitment, including a-priori screening for baseline diet quality and nutrient status, are discussed as essential design recommendations to ensure accurate interpretation of nutrient effects within the context of baseline participant characteristics.

Associations of Ultra-Processed and Unprocessed/Minimally Processed Food Consumption with Peripheral and Central Hemodynamics, and Arterial Stiffness in Young Healthy Adults

Consumption of ultra-processed food (UPF) replaces the intake of freshly prepared unprocessed/minimally processed food (MPF) and is positively associated with hypertension and cardiovascular disease (CVD). The objective of this observational study was to investigate the relation between (1) UPF and (2) MPF with peripheral and central blood pressure (BP), wave reflection, and arterial stiffness. Habitual dietary intake, ambulatory BP, augmentation index (AIx), and pulse wave velocity (PWV) were assessed in 40 normotensive young adults (15 M/25 W; 27 ± 1 y; body mass index 23.6 ± 0.5 kg/m²). UPF consumption was positively associated with overall and daytime peripheral systolic BP (B = 0.25, 95% confidence interval (CI) 0.03, 0.46, p = 0.029; B = 0.32, 95% CI 0.09, 0.56, p = 0.008, respectively), daytime diastolic BP (B = 0.18, 95% CI 0.01, 0.36, p = 0.049) and daytime peripheral pulse pressure (PP; B = 0.22, 95% CI 0.03, 0.41, p = 0.027). MPF consumption was inversely associated with daytime peripheral PP (B = −0.27, 95% CI −0.47, −0.07, p = 0.011), overall and daytime central systolic BP (B = −0.27, 95% CI −0.51, −0.02, p = 0.035; B = −0.31, 95% CI −0.58, −0.04, p = 0.024, respectively), and nighttime central PP (B = −0.10, 95% CI −0.19, −0.01, p = 0.042). Both UPF and MPF were not associated with AIx nor PWV. These data suggest avoidance of UPF and consumption of more MPF may reduce CVD risk factors.

Maternal Diet and the Serum Metabolome in Pregnancy: Robust Dietary Biomarkers Generalizable to a Multiethnic Birth Cohort

BACKGROUND

Advances in metabolomics are anticipated to decipher associations between dietary exposures and health. Replication biomarker studies in different populations are critical to demonstrate generalizability.

OBJECTIVES

To identify and validate robust serum metabolites associated with diet quality and specific foods in a multiethnic cohort of pregnant women.

DESIGN

In this cross-sectional analysis of 3 multiethnic Canadian birth cohorts, we collected semiquantitative FFQ and serum data from 900 women at the second trimester of pregnancy. We calculated a diet quality score (DQS), defined as daily servings of "healthy" minus "unhealthy" foods. Serum metabolomics was performed by multisegment injection-capillary electrophoresis-mass spectrometry, and specific serum metabolites associated with maternal DQSs were identified. We combined the results across all 3 cohorts using meta-analysis to classify robust dietary biomarkers (r > ± 0.1; P < 0.05).

RESULTS

Diet quality was higher in the South Asian birth cohort (mean DQS = 7.1) than the 2 white Caucasian birth cohorts (mean DQS <3.2). Sixty-six metabolites were detected with high frequency (>75%) and adequate precision (CV <30%), and 47 were common to all cohorts. Hippuric acid was positively associated with healthy diet score in all cohorts, and with the overall DQS only in the primarily white Caucasian cohorts. We observed robust correlations between: 1) proline betaine-citrus foods; 2) 3-methylhistidine-red meat, chicken, and eggs; 3) hippuric acid-fruits and vegetables; 4) trimethylamine N-oxide (TMAO)-seafood, meat, and eggs; and 5) tryptophan betaine-nuts/legumes.

CONCLUSIONS

Specific serum metabolites reflect intake of citrus fruit/juice, vegetables, animal foods, and nuts/legumes in pregnant women independent of ethnicity, fasting status, and delays to storage across multiple collection centers. Robust biomarkers of overall diet quality varied by cohort. Proline betaine, 3-methylhistidine, hippuric acid, TMAO, and tryptophan betaine were robust dietary biomarkers for investigations of maternal nutrition in diverse populations.

Ultra-processed foods and binge eating: A retrospective observational study

OBJECTIVES

There is increasing evidence of the impact of ultra-processed foods on multiple metabolic and neurobiological pathways, including those involved in eating behaviors, both in animals and in humans. In this study we aimed to explore ultra-processed foods and their link with disordered eating in a clinical sample.

METHODS

This was a single site, retrospective observational study in a specialist eating disorder service using self-report on the electronic health records. Patients with a Diagnostic and Statistical Manual of Mental Disorders (fifth edition) diagnosis of anorexia nervosa (AN), bulimia nervosa (BN), or binge eating disorder (BED) were randomly selected from the service database in Oxford from 2017 to 2019. The recently introduced NOVA classification was used to determine the degree of industrial food processing in each patient's diet. Frequencies of ultra-processed foods were analyzed for each diagnosis at each mealtime and during episodes of binging.

RESULTS

A total of 70 female and 3 male patients were included in the study; 22 had AN, 25 BN, and 26 BED. Patients with AN reported consuming 55% NOVA-4 foods, as opposed to approximately 70% in BN and BED patients. Foods that were consumed in a binge pattern were 100% ultra-processed.

CONCLUSION

Further research into the metabolic and neurobiological effects of ultra-processed food intake on disordered eating, particularly on binging, is needed.

Falsehoods and facts about dietary sugars: a call for evidence-based policy

Sugar, tobacco, and alcohol have been demonized since the seventeenth century. Yet unlike tobacco and alcohol, there is indisputable scientific evidence that dietary sugars were essential for human evolution and are essential for human health and development. Therefore, the purpose of this analytic review and commentary is to demonstrate that anti-sugar rhetoric is divorced from established scientific facts and has led to politically expedient but ill-informed policies reminiscent of those enacted about alcohol a century ago in the United States. Herein, we present a large body of interdisciplinary research to illuminate several misconceptions, falsehoods, and facts about dietary sugars. We argue that anti-sugar policies and recommendations are not merely unscientific but are regressive and unjust because they harm the most vulnerable members of our society while providing no personal or public health benefits.

DHA-enriched fish oil reduces insulin resistance in overweight and obese adults

Adipose tissue inflammation is major factor in the development of insulin resistance (IR). Long-chain omega-3 polyunsaturated fatty acids (LCn-3PUFA) docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are anti-inflammatory bioactive lipids, thus may protect against type 2 diabetes (T2D) development. Previous research has demonstrated a sex-dependent association between LCn-3PUFA and T2D, and evidence suggests LCn-3PUFA may improve IR in a sex-dependent manner. This double-blind, randomized, parallel-arm placebo-controlled study aimed to determine whether DHA-enriched fish oil (FO) supplementation improves IR. Sex-dependent effects were assessed by testing for an interaction between sex and treatment in the multiple regression models. Men and women with abdominal obesity (waist circumference: males, ≥102 cm; females, ≥88 cm) and without diabetes were recruited from the community. Participants (age: 50.9 ± 12.7 years, female: 63.7%, BMI: 32.4 ± 6.6 kg/m²) were randomly allocated to either 2 g FO (860 mg DHA + 120 mg EPA) (intervention, n = 38) or 2 g corn oil (CO) /day (control, n = 35) for 12 weeks in a double-blind randomised controlled trial. A fasting blood sample was collected at 0 and 12 weeks for assessment of IR, glucose and blood lipid profile. Sixty-eight participants completed the intervention. Compared with CO (n = 32), FO (n = 36) significantly reduced fasting insulin by -1.62 μIU/L (95%CI: -2.99, -0.26,) (p = 0.021) and HOMA-IR by -0.40 units (95%CI: -0.78, -0.02, p = 0.038). Higher insulin and HOMA-IR at baseline were associated with greater reductions in the FO group (p < 0.001). There was no interaction between sex and treatment for the change in insulin (p-interaction_{sex*treatment} = 0.816) or HOMA-IR (p-interaction_{sex*treatment} = 0.825). DHA-enriched FO reduces IR in adults with abdominal obesity, however, sex-dependent differences were not evident in this study.

Wearable Technology to Quantify the Nutritional Intake of Adults: Validation Study

Background

Wearable and mobile sensor technologies can be useful tools in precision nutrition research and practice, but few are reliable for obtaining accurate and precise measurements of diet and nutrition.

Objective

This study aimed to assess the ability of wearable technology to monitor the nutritional intake of adult participants. This paper describes the development of a reference method to validate the wristband’s estimation of daily nutritional intake of 25 free-living study participants and to evaluate the accuracy (kcal/day) and practical utility of the technology.

Methods

Participants were asked to use a nutrition tracking wristband and an accompanying mobile app consistently for two 14-day test periods. A reference method was developed to validate the estimation of daily nutritional intake of participants by the wristband. The research team collaborated with a university dining facility to prepare and serve calibrated study meals and record the energy and macronutrient intake of each participant. A continuous glucose monitoring system was used to measure adherence with dietary reporting protocols, but these findings are not reported. Bland-Altman tests were used to compare the reference and test method outputs (kcal/day).

Results

A total of 304 input cases were collected of daily dietary intake of participants (kcal/day) measured by both reference and test methods. The Bland-Altman analysis had a mean bias of −105 kcal/day (SD 660), with 95% limits of agreement between −1400 and 1189. The regression equation of the plot was Y=−0.3401X+1963, which was significant (P<.001), indicating a tendency for the wristband to overestimate for lower calorie intake and underestimate for higher intake. Researchers observed transient signal loss from the sensor technology of the wristband to be a major source of error in computing dietary intake among participants.

Conclusions

This study documents high variability in the accuracy and utility of a wristband sensor to track nutritional intake, highlighting the need for reliable, effective measurement tools to facilitate accurate, precision-based technologies for personal dietary guidance and intervention.