Intake of whole grain and associations with lifestyle and demographics: a cross-sectional study based on the Danish Diet, Cancer and Health-Next Generations cohort

Recommendations for the Use of Dietary Fiber to Improve Blood Pressure Control

According to several international, regional, and national guidelines on hypertension, lifestyle interventions are the first-line treatment to lower blood pressure (BP). Although diet is one of the major lifestyle modifications described in hypertension guidelines, dietary fiber is not specified. Suboptimal intake of foods high in fiber, such as in Westernized diets, is a major contributing factor to mortality and morbidity of noncommunicable diseases due to higher BP and cardiovascular disease. In this review, we address this deficiency by examining and advocating for the incorporation of dietary fiber as a key lifestyle modification to manage elevated BP. We explain what dietary fiber is, review the existing literature that supports its use to lower BP and prevent cardiovascular disease, describe the mechanisms involved, propose evidence-based target levels of fiber intake, provide examples of how patients can achieve the recommended targets, and discuss outstanding questions in the field. According to the evidence reviewed here, the minimum daily dietary fiber for adults with hypertension should be >28 g/day for women and >38 g/day for men, with each extra 5 g/day estimated to reduce systolic BP by 2.8 mm Hg and diastolic BP by 2.1 mm Hg. This would support a healthy gut microbiota and the production of gut microbiota-derived metabolites called short-chain fatty acids that lower BP. Awareness about dietary fiber targets and how to achieve them will guide medical teams on better educating patients and empowering them to increase their fiber intake and, as a result, lower their BP and cardiovascular disease risk.

Effects of whole grains on glycemic control: a systematic review and dose-response meta-analysis of prospective cohort studies and randomized controlled trials

PURPOSE

Whole grains have recently been promoted as beneficial to diabetes prevention. However, the evidence for the glycemic benefits of whole grains seems to conflict between the cohort studies and randomized control trials (RCTs). To fill the research gap, we conducted a meta-analysis to determine the effects of whole grains on diabetes prevention and to inform recommendations.

METHODS

We searched PubMed, Clarivate Web of Science, and Cochrane Library until March 2024. We used the risk ratio (RR) of type 2 diabetes to represent the clinical outcomes for cohort studies, while the biomarkers, including fasting blood glucose and insulin, HbA1C, and HOMA-IR, were utilized to show outcomes for RCTs. Dose-response relationships between whole grain intakes and outcomes were tested with random effects meta-regression models and restricted cubic splines models. This study is registered with PROSPERO, CRD42021281639.

RESULTS

Ten prospective cohort studies and 37 RCTs were included. Cohort studies suggested a 50 g/day whole grain intake reduced the risk of type 2 diabetes (RR = 0.761, 95% CI: 0.700 to 0.828, I2 = 72.39%, P < 0.001) and indicated a monotonic inverse relationship between whole grains and type 2 diabetes rate. In RCTs, whole grains significantly reduced fasting blood glucose (Mean difference (MD) = -0.103 mmol/L, 95% CI: -0.178 to -0.028; I2 = 72.99%, P < 0.01) and had modest effects on HbA1C (MD = -0.662 mmol/mol (-0.06%), 95% CI: -1.335 to 0.010; I2 = 64.55%, P = 0.05) and HOMA-IR (MD = -0.164, 95% CI: -0.342 to 0.013; I2 = 33.38%, P = 0.07). The intake of whole grains and FBG, HbA1C, and HOMA-IR were significantly dose-dependent. The restricted spline curves remained flat up to 150 g/day and decreased afterward. Subgroup analysis showed that interventions with multiple whole-grain types were more effective than those with a single type.

CONCLUSION

Our study findings suggest that a daily intake of more than 150 g of whole grain ingredients is recommended as a population approach for diabetes prevention.

Composition of Whole Grain Dietary Fiber and Phenolics and Their Impact on Markers of Inflammation

Inflammation is an important biological response to any tissue injury. The immune system responds to any stimulus, such as irritation, damage, or infection, by releasing pro-inflammatory cytokines. The overproduction of pro-inflammatory cytokines can lead to several diseases, e.g., cardiovascular diseases, joint disorders, cancer, and allergies. Emerging science suggests that whole grains may lower the markers of inflammation. Whole grains are a significant source of dietary fiber and phenolic acids, which have an inverse association with the risk of inflammation. Both cereals and pseudo-cereals are rich in dietary fiber, e.g., arabinoxylan and β-glucan, and phenolic acids, e.g., hydroxycinnamic acids and hydroxybenzoic acids, which are predominantly present in the bran layer. However, the biological mechanisms underlying the widely reported association between whole grain consumption and a lower risk of disease are not fully understood. The modulatory effects of whole grains on inflammation are likely to be influenced by several mechanisms including the effect of dietary fiber and phenolic acids. While some of these effects are direct, others involve the gut microbiota, which transforms important bioactive substances into more beneficial metabolites that modulate the inflammatory signaling pathways. Therefore, the purpose of this review is twofold: first, it discusses whole grain dietary fiber and phenolic acids and highlights their potential; second, it examines the health benefits of these components and their impacts on subclinical inflammation markers, including the role of the gut microbiota. Overall, while there is promising evidence for the anti-inflammatory properties of whole grains, further research is needed to understand their effects fully.

Partial substitution of red meat or processed meat with plant-based foods and the risk of colorectal cancer

OBJECTIVES

Shifting from animal-based to plant-based diets could reduce colorectal cancer (CRC) incidence. Currently, the impacts of these dietary shifts on CRC risk are ill-defined. Therefore, we examined partial substitutions of red or processed meat with whole grains, vegetables, fruits or a combination of these in relation to CRC risk in Finnish adults.

METHODS

We pooled five Finnish cohorts, resulting in 43 788 participants aged ≥ 25 years (79% men). Diet was assessed by validated food frequency questionnaires at study enrolment. We modelled partial substitutions of red (100 g/week) or processed meat (50 g/week) with corresponding amounts of plant-based foods. Cohort-specific hazard ratios (HR) for CRC were calculated using Cox proportional hazards models and pooled together using random-effects models. Adjustments included age, sex, energy intake and other relevant confounders.

RESULTS

During the median follow-up of 28.8 years, 1124 CRCs were diagnosed. We observed small risk reductions when red meat was substituted with vegetables (HR 0.97, 95% CI 0.95 - 0.99), fruits (0.97, 0.94 - 0.99), or whole grains, vegetables and fruits combined (0.97, 0.95 - 0.99). For processed meat, these substitutions yielded 1% risk reductions. Substituting red or processed meat with whole grains was associated with a decreased CRC risk only in participants with < median whole grain intake (0.92, 0.86 - 0.98; 0.96, 0.93 - 0.99, respectively; pinteraction=0.001).

CONCLUSIONS

Even small, easily implemented substitutions of red or processed meat with whole grains, vegetables or fruits could lower CRC risk in a population with high meat consumption. These findings broaden our insight into dietary modifications that could foster CRC primary prevention.

Increasing fibre intake in the UK: lessons from the Danish Whole Grain Partnership

Diets deficient in fibre are reported globally. The associated health risks of insufficient dietary fibre are sufficiently grave to necessitate large-scale interventions to increase population intake levels. The Danish Whole Grain Partnership (DWP) is a public-private enterprise model that successfully augmented whole-grain intake in the Danish population. The potential transferability of the DWP model to Slovenia, Romania and Bosnia-Herzegovina has recently been explored. Here, we outline the feasibility of adopting the approach in the UK. Drawing on the collaborative experience of DWP partners, academics from the Healthy Soil, Healthy Food, Healthy People (H3) project and food industry representatives (Food and Drink Federation), this article examines the transferability of the DWP approach to increase whole grain and/or fibre intake in the UK. Specific consideration is given to the UK's political, regulatory and socio-economic context. We note key political, regulatory, social and cultural challenges to transferring the success of DWP to the UK, highlighting the particular challenge of increasing fibre consumption among low socio-economic status groups - which were also most resistant to interventions in Denmark. Wholesale transfer of the DWP model to the UK is considered unlikely given the absence of the key 'success factors' present in Denmark. However, the DWP provides a template against which a UK-centric approach can be developed. In the absence of a clear regulatory context for whole grain in the UK, fibre should be prioritised and public-private partnerships supported to increase the availability and acceptability of fibre-rich foods.

The Relationship between Whole-Grain Intake and Measures of Cognitive Decline, Mood, and Anxiety-A Systematic Review

Greater intake of whole grains, compared to refined grains, is consistently associated with a reduced risk of cardiovascular disease and type 2 diabetes, both of which are associated with cognitive decline. To better understand the relationship between whole-grain intake, cognition, mood, and anxiety, a systematic review was conducted to synthesize available evidence linking whole grains to these outcomes. Four electronic databases were searched from inception to August 2021 for potentially relevant observational and interventional studies. Risk of bias (RoB) assessments were performed using the newly developed Nutrition Quality Evaluation Strengthening Tools, and the Grades of Recommendation, Assessment, Development, and Evaluation approach was used to determine the strength of evidence for each outcome. In total, 23 studies [4 randomized controlled trials (RCTs) and 19 observational studies] met the predefined eligibility criteria. Of these,12 studies included analysis of whole-grain intake and cognitive decline, 9 included mood outcomes, and 2 included both cognition and mood outcomes. The overall evidence for an association between whole-grain intake and cognition is inconclusive. With respect to mood outcomes, evidence from RCTs prospective cohort and case-control studies suggest that higher intake is linked to improved outcomes for mood and depression although the evidence is mixed for cross-sectional studies. Reporting of whole-grain intake fell short of suggested standards, and the strength of available evidence was low or very low for all outcomes. A high RoB toward studies reporting results was also noted, complicating both the interpretation of some studies and the combined evidence. Of note, few well-designed RCTs assessing the effect of whole-grain intake on measures of cognition, mood, and anxiety were identified, highlighting the need for more studies in this area. The available, although limited, evidence suggests that greater whole-grain intake is associated with better mood and anxiety-related scores and is inconclusive regarding cognitive outcomes. PROSPERO registration: CRD42021266355.

Dietary polyphenols, metabolic syndrome and cardiometabolic risk factors: An observational study based on the DCH-NG subcohort

BACKGROUND AND AIMS

Polyphenol-rich foods have beneficial properties that may lower cardiometabolic risk. We aimed to prospectively investigate the relationship between intakes of dietary polyphenols, and metabolic syndrome (MetS) and its components, in 676 Danish residents from the MAX study, a subcohort of the Danish Diet, Cancer and Health-Next Generations (DCH-NG) cohort.

METHODS AND RESULTS

Dietary data were collected using web-based 24-h dietary recalls over one year (at baseline, and at 6 and 12 months). The Phenol-Explorer database was used to estimate dietary polyphenol intake. Clinical variables were also collected at the same time point. Generalized linear mixed models were used to investigate relationships between polyphenol intake and MetS. Participants had a mean age of 43.9y, a mean total polyphenol intake of 1368 mg/day, and 75 (11.6%) had MetS at baseline. Compared to individuals with MetS in Q1 and after adjusting for age, sex, lifestyle and dietary confounders, those in Q4 - for total polyphenols, flavonoids and phenolic acids-had a 50% [OR (95% CI): 0.50 (0.27, 0.91)], 51% [0.49 (0.26, 0.91)] and 45% [0.55 (0.30, 1.00)] lower odds of MetS, respectively. Higher total polyphenols, flavonoids and phenolic acids intakes as continuous variable were associated with lower risk for elevated systolic blood pressure (SBP) and low high-density lipoprotein cholesterol (HDL-c) (p < 0.05).

CONCLUSIONS

Total polyphenol, flavonoid and phenolic acid intakes were associated with lower odds of MetS. These intakes were also consistently and significantly associated with a lower risk for higher SBP and lower HDL-c concentrations.

Relative Validity and Reproducibility of a Web-Based Semi-Quantitative Food Frequency Questionnaire in the Danish Diet, Cancer, and Health-Next Generations MAX Study

The food frequency questionnaire (FFQ) is designed to capture an individual's habitual dietary intake and is the most applied method in nutritional epidemiology. Our aim was to assess the relative validity and reproducibility of the FFQ used in the Diet, Cancer, and Health-Next Generations cohort (DCH-NG). We included 415 Danish women and men aged 18-67 years. Spearman's correlations coefficients, Bland-Altman limits of agreement and cross-classification between dietary intakes estimated from the FFQ administered at baseline (FFQ_baseline), and the mean of three 24-h dietary recalls (24-HDRs) and the FFQ administered after 12 months (FFQ_{12 months}) were determined. Nutrient intakes were energy-adjusted by Nutrient Density and Residual methods. Correlation coefficients ranged from 0.18-0.58 for energy and energy-adjusted nutrient intakes, and the percentage of participants classified into the same quartile ranged from 28-47% between the FFQ_baseline and the 24-HDRs. For the FFQ_{12 months} compared with FFQ_baseline, correlation coefficients ranged from 0.52-0.88 for intakes of energy, energy-adjusted nutrients, and food groups, and the proportion of participants classified into the same quartiles ranged from 43-69%. Overall, the FFQ provided a satisfactory ranking of individuals according to energy, nutrient, and food group intakes, making the FFQ suitable for use in epidemiological studies investigating diet in relation to disease outcomes.

Adherence to the EAT-Lancet diet is associated with a lower risk of type 2 diabetes: the Danish Diet, Cancer and Health cohort

PURPOSE

Type 2 diabetes is a global health problem. While a healthy diet lowers risk of type 2 diabetes, less is known about diets with low climate impact. This study aimed to investigate adherence to the EAT-Lancet diet and risk of type 2 diabetes in a Danish setting.

METHODS

In the Danish Diet, Cancer and Health cohort, dietary data were collected using a validated 192-item food frequency questionnaire, at recruitment in 1993-1997. In total, 54,232 participants aged 50-64 years at baseline with no previous cancer or diabetes diagnoses were included in the current analyses. The EAT-Lancet diet score was used to assess adherence to the EAT-Lancet diet. Participants scored 0 (non-adherence) or 1 (adherence) point for each of the 14 dietary components of the diet score (range 0-14 points). Participants were followed through register linkage until type 2 diabetes diagnosis or censoring. Hazard ratios and 95% confidence intervals (CI) were estimated using multivariable-adjusted Cox regression models.

RESULTS

During a median 15-year follow-up period, 7130 participants developed type 2 diabetes. The hazard ratio for developing type 2 diabetes was 0.78 (95% CI 0.71; 0.86) for those with highest EAT-Lancet diet scores (11-14 points) compared to those with lowest scores (0-7 points) after adjusting for potential confounders. After further adjusting for potential mediators, including BMI, the corresponding hazard ratio was 0.83 (95% CI 0.76; 0.92).

CONCLUSION

Greater adherence to the EAT-Lancet diet was associated with a lower risk of developing type 2 diabetes in a middle-aged Danish population.

High consumption of whole grain foods decreases the risk of dementia and Alzheimer's disease: Framingham Offspring Cohort

AIMS

To examine the longitudinal associations between total and individual whole grain (WG) food intake and the risk of all-cause dementia and Alzheimer's disease (AD) dementia.

METHODS

This study included 2958 subjects (mean age at baseline was 61 ± 9 years) from the Framingham Offspring Cohort. Standardized interviews, physician examinations, and laboratory tests were collected approximately every 4 years, and the Food Frequency Questionnaire (FFQ) was conducted in cycle 5. Proportional hazards models and cubic spline regression examined associations between WG foods and all-cause dementia and AD dementia.

RESULTS

Over an average of 12.6 years of follow-up, there were 322 dementia cases, of which 247 were AD dementia. After multivariate and dietary adjustments, individuals with the highest category for total WG food consumption had a lower risk of all-cause dementia [HR 0.66, 95% confidence interval (CI) 0.51-0.81] and AD dementia (HR 0.60, 95% CI 0.46-0.78) than individuals with the lowest category. The results remained comparable in different subgroups stratifying for age, sex, education, body mass index, and smoking status without significant interaction. Moreover, these inverse associations were seen for most individual WG foods except popcorn. A nonlinear dose-response association was shown between total WG intake and all-cause dementia and AD dementia, where the rate reduction slightly plateaued at more than one and two servings/day, respectively.

CONCLUSIONS

Higher consumption of total and several common individual WG foods was strongly associated with a lower risk of all-cause dementia and AD dementia.

Serum metabolites associated with wholegrain consumption using nontargeted metabolic profiling: a discovery and reproducibility study

PURPOSE

To identify fasting serum metabolites associated with WG intake in a free-living population adjusted for potential confounders.

METHODS

We selected fasting serum samples at baseline from a subset (n = 364) of the prospective population-based Kuopio Ischaemic Heart Disease Risk Factor Study (KIHD) cohort. The samples were analyzed using nontargeted metabolomics with liquid chromatography coupled with mass spectrometry (LC-MS). Association with WG intake was investigated using both random forest followed by linear regression adjusted for age, BMI, smoking, physical activity, energy and alcohol consumption, and partial Spearman correlation adjusted for the same covariates. Features selected by any of these models were shortlisted for annotation. We then checked if we could replicate the findings in an independent subset from the same cohort (n = 200).

RESULTS

Direct associations were observed between WG intake and pipecolic acid betaine, tetradecanedioic acid, four glucuronidated alkylresorcinols (ARs), and an unknown metabolite both in discovery and replication cohorts. The associations remained significant (FDR<0.05) even after adjustment for the confounders in both cohorts. Sinapyl alcohol was positively correlated with WG intake in both cohorts after adjustment for the confounders but not in linear models in the replication cohort. Some microbial metabolites, such as indolepropionic acid, were positively correlated with WG intake in the discovery cohort, but the correlations were not replicated in the replication cohort.

CONCLUSIONS

The identified associations between WG intake and the seven metabolites after adjusting for confounders in both discovery and replication cohorts suggest the potential of these metabolites as robust biomarkers of WG consumption.

Descriptive analysis of dietary (poly)phenol intake in the subcohort MAX from DCH-NG: "Diet, Cancer and Health-Next Generations cohort"

PURPOSE

(Poly)phenols are bioactive compounds widely distributed in plant-based foods. Currently, limited data exist on the intake distribution of (poly)phenols across meals. This study aimed to estimate dietary intakes of all individual (poly)phenols and total intake per class and subclass by meal event, and to identify their main food sources in the subcohort MAX from the Diet, Cancer and Health-Next Generations cohort (DCH-NG).

METHODS

Dietary data were collected using three web-based 24-h dietary recalls over 1 year. In total, 676 participants completed at least one recall. The dietary data were linked to Phenol-Explorer database using standardized procedures and an in-house software. We categorized foods/drinks into five options of meal events selected by the participant: 'Breakfast', 'Lunch', 'Evening', 'Snack', and 'Drink'.

RESULTS

Adjusted total (poly)phenols mean intake by meal was the highest in the drink event (563 mg/day in men and 423 mg/day in women) and the lowest in the evening event (146 mg/day in men and 137 mg/day in women). The main overall (poly)phenol class contributor was phenolic acids (55.7-79.0%), except for evening and snack events where it was flavonoids (45.5-60%). The most consumed (poly)phenol subclasses were hydroxycinnamic acids and proanthocyanidins. Nonalcoholic beverages (coffee accounted for 66.4%), cocoa products, and cereals were the main food sources of total (poly)phenols.

CONCLUSION

This study provides data on the variability in the intake of classes and subclasses of (poly)phenols and their main food sources by meal event according to lifestyle data, age, and gender in a Danish population.

Knowledge, Messaging, and Selection of Whole-Grain Foods: Consumer and Food Industry Perspectives

OBJECTIVE

To explore whole-grain food definitions in labeling and relevance to consumers and the food industry.

DESIGN

Semistructured focus groups and interviews.

SETTING

Online.

PARTICIPANTS

Consumers (n = 43) aged ≥ 18 years currently purchasing/consuming grain foods. Food industry participants (n = 17) currently/recently employed within grain food companies.

PHENOMENON OF INTEREST

Impact of using whole-grain food definitions in labeling.

ANALYSIS

Inductive thematic analysis.

RESULTS

Six major themes included: consumer knowledge and understanding of whole-grain foods; factors affecting consumer grain food choices; consumer skepticism of labeling; consumer preferences toward whole-grain labeling; acceptability and feasibility of whole-grain food definitions in the food industry; and food innovation/reformulation. For the food industry, definitions impact feasibility, food innovation, and reformulation. Skepticism affected consumer knowledge and understanding, impacting grain food choice and their preference regarding whole-grain labeling. Consumers preferred whole grain in the name of a food and placing the percent of whole grain on the front-of-pack.

CONCLUSIONS AND IMPLICATIONS

Our findings suggest that definitions and regulations, consumer education, and strategies addressing factors influencing consumer choice are needed to improve population whole-grain intakes. Future research may consider formal regulation and implementation of standardized whole-grain food definitions in labeling and explore the subsequent impact on consumer choice and whole-grain intake.

Development of Green UV-Vis Method for Direct Determination of Total Sugars in the Aqueous Extract of Teff (Eragrostis tef (Zuccagni) Trotter) Grains and Other Cereals

There is no ultraviolet visible (UV-Vis) spectrophotometric method for the direct determination of total sugars in the aqueous extract of teff grain samples. Therefore, the objective of this study was to develop a green UV-Vis spectrophotometric method to determine total sugars in the aqueous extract of white teff, brown teff, white rice, and red wheat grain samples. The calibration curve was established in the range of 20.11-7,907 mg/L using sucrose as a standard with R ² = 0.9996. The limit of detection and limit of quantification were 4.4 and 14.6 mg/L, respectively. The relative standard deviation (6.9%) of the method for the sucrose standard was within the acceptable range indicating that the method is precise. The amount of total sugars determined in the white teff (5.48-9.44% (w/w), brown teff (6.17-10.32% (w/w)), white rice (3.19% (w/w)), and red wheat (9.22% (w/w)) grain samples was comparable with other reported cereal grains. Furthermore, the accuracy of the developed analytical method was also evaluated by spiking the known amount of the sucrose standard solution to the white teff, brown teff, white rice, and red wheat sample extracts, and percentage recoveries found were in the acceptable range (85 ± 2 - 105 ± 4%) with an average recovery of 93%, confirming that the new green method is quantitatively reproducible. Hence, a fast, simple, inexpensive, widely used, selective, sensitive, precise, and accurate green UV-Vis method was developed and validated for the direct determination of total sugars in the aqueous extract of teff, white rice, and red wheat grain samples.

Factors Affecting a Healthy Diet Based on the Integrated Model for Behavioral Change in Patients with Gastric Cancer: Cross-Sectional Study

Objective

To investigate the factors affecting a healthy diet in patients with gastric cancer.

Methods

Data from 146 consecutive patients with gastric cancer were collected based on the integrated model for behavior change. Core theory constructs were operationalized with decisional balance on a healthy diet, self-efficacy in fruit and vegetable (F&V) intake and diet planning, coping planning and self-leadership, and stages of change in F&V intake and adhering to a diet plan.

Results

Higher self-efficacy in F&V intake and diet planning were associated with a higher readiness for change in F&V intake (adjusted odds ratio [aOR] for self-efficacy, 1.02; 95% confidence interval [CI], 1.01–1.04) and for adhering to a diet plan (aOR for self-efficacy, 1.02; 95% CI, 1.01–1.04; aOR for diet planning, 1.02; 95% CI, 1.01–1.04). Coping planning was a determinant of readiness for change in F&V intake (aOR, 1.02; 95% CI, 1.01–1.04). Self-leadership in behavioral awareness and volition (aOR, 1.02; 95% CI, 1.01–1.03) and task motivation (aOR, 1.02; 95% CI, 1.00–1.03) were determinants of readiness for change in adhering to a diet plan.

Conclusions

Self-efficacy and coping planning were determinants of readiness for change in F&V intake in patients with gastric cancer. Self-efficacy and self-leadership were determinants of readiness for change in adhering to a diet plan in patients with gastric cancer. Improving self-efficacy, coping planning, and self-leadership is essential for changing behaviors to adopt a healthy diet. Nurses caring for patients with gastric cancer should identify strategies that improve self-efficacy in F&V intake and diet planning.

Perspective: Why Whole Grains Should Be Incorporated into Nutrient-Profile Models to Better Capture Nutrient Density

Healthy eating patterns, as described by dietary guidelines, typically favor whole grains, low-fat dairy, vegetables, fruit, legumes, and nuts and seeds. Nutrient-profiling (NP) models capture nutrient density of individual foods and can inform healthier food choices. Although whole grains are prominently featured in most dietary guidelines, they are not included in most NP models. Healthy foods, as identified by most NP models, are those that contain limited amounts of energy, saturated fat, total or added sugar, and sodium. As global dietary guidance turns to foods and food groups as opposed to individual nutrients, future nutrient-density metrics may need to do the same. Potential methods to incorporate whole grains into the overall concept of nutrient density and into selected NP models are outlined in this review. Incorporating whole grains into the Nutri-Score, Health Star Rating, or the Nutrient Rich Food index will require further analyses of dietary nutrient density in relation to health outcomes across diverse population subgroups. We present the rationale for how the inclusion of whole grains in NP models can assist in the implementation of dietary guidance.

Whole Grain Food Definition Effects on Determining Associations of Whole Grain Intake and Body Weight Changes: A Systematic Review

Within epidemiological and intervention studies, whole grain consumption has generally shown positive associations with reductions in markers of overweight and obesity. However, studies use varied methods of determining whole grain intake, including different definitions of a whole grain food, which may explain varied results. This systematic review aimed to identify how different methods of reporting and calculating whole grain intake, including whole grain food definitions, affect reported associations between whole grain intake and body weight measures in adults. Systematic searching of PubMed, Scopus, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane Central Register for Controlled Trials (CENTRAL), and MEDLINE (all years to 11 June, 2020) identified eligible studies. Cohort and cross-sectional studies assessing whole grain intake and body weight measures in adults were included. Studies that did not specify methods used to calculate whole grain intake were excluded. Twenty-one cross-sectional studies (from 24 articles) and 9 prospective cohort studies (from 7 articles) were included in the review. Many cross-sectional studies showed whole grain intake was, to some degree, significantly associated with body weight measures, whereas associations varied greatly among cohort studies. Studies calculating whole grain intake using total grams of intake, USDA databases, or ≥25% whole grain in combination with listing specific foods, showed consistent beneficial effects of increasing whole grain intake on body weight. Studies with general lists of foods included as "whole grain foods" or lower cut-offs for whole grain content were inconsistent. The majority of studies reported whole grain intake as servings/day or grams whole grain/day. This review suggests that an association between whole grain and body weight measures remains likely, although precise associations are difficult to determine due to heterogeneity in methodologies and an inability to formally compare studies. Moving forward, application of a standardized methodology to calculate whole grain intake is essential.