Relationship between Village Chicken Availability and Dietary Diversity along a Rural-Urban Gradient.

Dietary diversity is one of the fundamental factors of nutritional security and a proxy used to measure diet quality. The objective of this study was to investigate the relationship between village chicken availability and the dietary diversity of households along a rural-urban gradient. Face-to-face interviews were conducted using a structured questionnaire in rural (n = 100), peri-urban (n = 100), and urban (n = 100) areas of Pietermaritzburg uMgungundlovu District, KwaZulu-Natal, in South Africa. A positive relationship between distance from the city center and village chicken flock sizes (p < 0.001) was observed. Consumption of vegetables increased with an increase in distance from the city center (p < 0.01). A quadratic relationship was observed between distance from the city center and consumption of livestock-derived foods (LDFs) (p < 0.05). Consumption of LDFs increased with an increase in village chicken flock sizes (p < 0.05). Consumption of vegetables increased with an increase in village chicken flock sizes (p < 0.01). Food variety score (FVS) increased with an increase in distance from the city center (p < 0.05). Assessing the availability of village chickens across rural-urban gradients is a worthy opportunity to utilize to improve households' dietary diversity and alleviate poverty. It can be concluded that expanding village flock sizes could enhance the dietary diversity of households.

Exploring within-meal variety to promote appeal of home-cooked meals in older adults.

Undernutrition is highly prevalent in older adults and poses a major threat to physical and mental wellbeing. To foster healthy eating (and healthy aging), strategies are needed to improve dietary quality of older adults. In this study, the feasibility of increasing food variety in home-cooked meals is explored as strategy to promote meat and vegetable consumption in community dwelling older adults. Adults aged 50 years or older (N = 253) evaluated pictures of traditional Dutch dinner meals with more or less variety in the vegetable or meat component in an online questionnaire. Specifically, four different variety 'levels' were presented: (1) no variety, (2) meat variety, (3) vegetable variety, and (4) variety in both meat and vegetables (mixed). Participants indicated for each meal picture how much they would like the meal, whether it represented an ideal portion size, and whether they would be able and willing to prepare the meal. We expected that with increasing variety, liking and ideal portion size would increase, while ability and willingness to prepare the meals would decrease. Results showed that the meals with meat variety and mixed variety were liked less than meals with vegetable variety or no variety. Participants were all highly willing to prepare the meals, but they were less willing to prepare the meals with meat variety and mixed variety compared to the meals with vegetable variety and no variety. All meals were evaluated as being too large, but the meals with vegetable variety and mixed variety were evaluated as more oversized than the meals without variety and with meat variety. These results suggest that encouraging older adults to include variety in home-cooked meals might be more challenging than anticipated.

Higher meal disengagement and meal presentation are uniquely related to psychological distress and lower quality of life in undergraduate students.

Objective: Picky eating, which occurs in emerging adulthood and is associated with psychological distress and quality of life, has historically been conceptualized as unidimensional despite research suggesting it is a multifaceted construct. Participants: An undergraduate sample (N = 509; Mage = 19.96). Methods: A cross-sectional survey assessed picky eating facets (food variety, meal disengagement, meal presentation, and taste aversion), disordered eating, anxiety, depression, stress, obsessive compulsive disorder (OCD), and social phobia symptoms, and quality of life. Results: Meal disengagement was uniquely related to higher anxiety, depression, stress, and social phobia symptoms and lower quality of life, whereas meal presentation was uniquely related to higher anxiety, stress, and OCD symptoms, beyond covariates and disordered eating. Food variety and taste aversion were not uniquely related to outcomes. Conclusions: Considering picky eating multidimensionally may yield important insights beyond the broader construct in terms of its relationship with psychological well-being in undergraduates.

Dietary diversity and food variety scores and their association with nutrition and health status of Indian children and adolescents: A multicenter study.

BACKGROUND: The objectives of this study were to 1) evaluate the dietary diversity scores (DDS) and food variety scores (FVS) among Indian children and adolescents aged 9-18 y; 2) compare the DDS and FVS in association with demographic, socioeconomic, and health characteristics (growth and hemoglobin [Hb] concentrations); and 3) determine DDS and FVS cutoffs to identify dietary micronutrient adequacy. METHODS: This study was performed in a subset (n = 1845) of children and adolescents enrolled in a multicenter study (2016-2017) from urban and rural areas of six Indian states. Height, weight, and Hb were measured, and anthropometric Z-scores were computed. Sociodemographic data were collected using a structured questionnaire. Dietary data collected by 24-h dietary recall were used to calculate the DDS and FVS. The mean adequacy ratio (MAR) for 10 micronutrients was computed. Receiver operating characteristic analysis was performed to define cutoffs of DDS and FVS. RESULTS: In comparison with children and adolescents from rural areas, urban children and adolescents consumed more diverse diets (urban, 4.1 ± 1.1; rural, 3.5 ± 1; P < 0.01) and had a higher mean FVS (urban, 19.9 ± 5.7; rural, 15.9 ± 4.5; P < 0.01). Both the DDS and FVS were significantly correlated with each other (r = 0.860; P < 0.01) and were positively correlated with MAR, growth, and Hb (P < 0.001) and mother's educational level (P < 0.01). The cutoffs of ≥6.5 (DDS) and ≥17 (FVS) were determined to predict micronutrient adequacy. CONCLUSIONS: Both the DDS and FVS can be used interchangeably for assessing growth, health status, and nutritional adequacy. Single cutoff values of the DDS and FVS may aid in prompt identification of children and adolescents with micronutrient inadequacy.

Associations between dietary variety, portion size and body weight: prospective evidence from UK Biobank participants.

'Dietary variety' has been identified as a factor associated with food intake. Whilst this relationship may have longer-term benefits for body weight management when eating low-energy, nutrient-dense foods, it may increase the risk of overconsumption (and body adiposity) when foods are high energy density. This study sought to further explore pathways underpinning the relationship between dietary variety and body weight, by considering energy density as a moderating factor and portion size as a mediating factor in this relationship. Using prospective data from the UK Biobank, dietary variety scores (DVS), cumulative portion size and energy density were derived from 24-h dietary recall questionnaires at baseline and follow-up. BMI, whole-body fat percentage and fat-free mass were included as outcomes. Contrary to predictions, linear multiple regression models found some evidence of a negative, direct association between DVS and body weight outcomes at baseline (b = -0·13). Though dietary variety was significantly associated with larger portions across time points (b = 41·86-82·64), a moderated mediation effect was not supported at baseline or follow-up (Index ≤ 0·035). Taken together, these findings provide population-level evidence to support a positive association between variety and food intake, which in turn has potential implications for body weight management, both in terms of moderating food intake and benefitting diet quality.

Seasonality- and disaster effects on food variety and food insecurity coping strategies among a landslide-prone cohort.

BACKGROUND & AIMS: Landslides may impact on nutritional health among vulnerable populations. However, there is limited data on the seasonal effects of landslides on diet and food security. Among the 2010 and 2018 households affected by the landslides in Eastern Uganda, we assessed seasonality and disaster effects on food varieties consumed and food insecurity coping strategies. This study is among the first to report on seasonal- and disaster effects on food varieties and food insecurity coping strategies among vulnerable populations in Uganda. METHODS: We used a three-stage simple random technique to select a total of 422 households during May-August (food-plenty season) in 2019, of whom 211 had been affected by the landslides and 211 had not (controls). Six months later, in January-March (food-poor season) of 2020, 388 households were re-assessed (191 affected and 197 controls). We analyzed data only from the households that participated in both food seasons to compare results between the two food seasons. Food variety scores (FVS) were obtained by summing the frequency of weekly intakes of 86 food items while a coping index was derived based on the severity weighting of household food insecurity coping strategies. RESULTS: After adjusting for covariates, significantly lower mean (SE) FVS were among the affected than controls during the food-plenty season: 9.3 (0.5) vs 11.4 (0.3), and during the food-poor season: 7.6 (0.5) vs 10.1 (0.1) (P < 0.001 for both). The affected households were more likely to use food insecurity coping strategies compared to controls (mean [SE]: 35.2 [2.1] vs. 27.1 [1.8], P < 0.001) during the food-plenty season and the severity further increased during the food-poor season: 42.1 (2.1) vs. 28.2 (2.1) (P < 0.001). Disaster exposure was associated with both household food varieties and food insecurity coping strategies during both food seasons (P < 0.001). The adjusted models, showed that, the affected compared to the controls had a significantly higher likelihood to rely on 5 of the 11 coping strategies during food-plenty season and 9 of the 11 coping strategies during the food-poor season. CONCLUSION: Low variety diets and coping strategies among disaster affected individuals cut across seasons and implies needs for strong social protection and targeted safety nets irrespective of season.

Long-Term Food Variety and Dietary Patterns Are Associated with Frailty among Chinese Older Adults: A Cohort Study Based on CLHLS from 2014 to 2018.

(1) Objective: To examine the association between posterior-derived dietary patterns, food variety, and frailty measured by frailty index (FI) in Chinese elderly. (2) Method: A cohort study based on the Chinese Longitudinal Healthy Longevity Survey (CLHLS) from 2014 to 2018 was conducted among older adults. The food variety was defined by the food variety score (FVS), which was calculated using the frequency of food categories consumption. Dietary patterns were obtained using factor analysis. A FI composed of 38 health deficits was used to measure subjects' frailty status. Logistic regression analyses were performed to explore the correlation between dietary factors and the incidence of frailty. (3) Results: Compared with low FVS, a high dietary diversity score at baseline was not associated with a reduced incidence of frailty after four years. Regarding long-term food variety, compared with the low variety maintained group, people with high variety maintained were associated with a lower risk of frailty (0.59, 95%CI 0.39-0.90). Adherence to the "egg-bean-pickle-sugar pattern" and "fruit-vegetable-meat-fish pattern" was associated with a lower risk of frailty. (4) Conclusion: Maintaining high food variety and adherence to two patterns, i.e., the egg-bean-pickle-sugar pattern and fruit-vegetable-meat-fish pattern, could reduce the incidence of frailty among Chinese older adults.

Association of dietary diversity with all-cause mortality by body mass index in Japanese older adults: An age-specific prospective cohort study (NISSIN project).

AIM: Dietary diversity might reduce the risk of malnutrition, although it is also linked to obesity. We examined whether dietary diversity is associated with all-cause mortality in Japanese older adults based on their body mass index (BMI). METHODS: The current study included 2944 people aged 64-65 years who participated in the New Integrated Suburban Seniority Investigation (NISSIN) project from 1996 to 2005. Dietary diversity was measured using the Food Variety Score (FVS), which calculates the frequency of all food items consumed daily using a self-administered food frequency questionnaire. Participants were divided into tertiles according to their FVS (first: low, second: middle, third: high). Multivariate adjusted hazard ratios with 95% confidence intervals were calculated using the Cox proportional hazard regression model. For the stratified analysis, BMI was used to divide the participants into three groups - lean (BMI <20), normal (BMI 20-24.9) and overweight/obese (BMI ≥25). RESULTS: Overall, 454 (30.7%) men and 222 (15.2%) women died over a median follow-up period of 16.6 years. No significant association was observed between FVS and all-cause mortality. However, when grouped by BMI, for the participants in the lean group, the multivariate adjusted hazard ratios were 0.56 (95% confidence interval 0.32-0.96) for the middle FVS and 0.50 (95% confidence interval 0.25-1.02) for the high FVS, compared with the low FVS (P for trend = 0.059). In overweight/obese women, although not significant, total mortality was higher in the middle and high FVS. CONCLUSIONS: These findings show that dietary diversity should be promoted in lean older Japanese adults. Geriatr Gerontol Int 2022; 22: 736-744.

Dietary practice among cohort pregnant women who gave birth to neonates with and without neural tube defect: a comparative cross-sectional study.

Despite the high burden of neural tube defects (NTD) in eastern Ethiopia, there is no evidence that it is related to maternal dietary practice. The aim of the present study was to compare dietary practice between women who gave birth to newborns with and without NTDs. A comparative cross-sectional study was performed on a total of 276 (138 in each group) mothers who delivered neonates with or without NTD. Study participants were selected from three hospitals found in the eastern part of Ethiopia. The dietary practice was determined using the indicators including meal frequency, dietary diversity score (DDS), food variety score (FVS) and consumption of animal source food (ASF) generated from the dietary data collected using validated and pre-tested Food Frequency Questionnaire (FFQ). A multivariable logistic regression model was fitted to isolate independent predictors of dietary practices. The prevalence of good dietary practice was 29 % (95 % CI 23·6 %, 34·3 %). There was a significant difference in dietary practices (P = 0·034), in FVS (P = 0·01), in DDS (P = 0·045) between the two groups. In multivariable logistic regression, independent predictors of having good dietary practice were: not being the mother of a newborn with NTDs [adjusted odds ratio (AOR) 2·1, 95 % CI 1·07, 4·1], being from a rural residence area (AOR 0·29, 95 % CI 0·1, 0·7) and being illiterate (AOR 0·16, 95 % CI 0·03, 0·8). The present study found that dietary practice is associated with the development of NTDs. Nutrition education, food fortification and supplementation are needed to address this issue, and further research is needed to explore the mechanism.

Prevalence and determinants of dietary practices among pregnant women in eastern Ethiopia.

INTRODUCTION: Appropriate dietary practices in pregnancy are critical to meet the increased metabolic and physiological demands; however, information about dietary practices among pregnant women, particularly rural residents, is limited. The study aimed to assess the level of appropriate dietary practices and associated determinants among pregnant women in Haramaya District, eastern Ethiopia, 2021. METHODS: A community-based cross-sectional study was conducted among 448 pregnant women in Haramaya District, Eastern Ethiopia. Data was collected through face-to-face interviews by trained research assistants, using a validated frequency questionnaire. The pregnant women were labeled as "appropriate dietary practice" when they consumed at least four meals daily, had a good food variety score, high dietary diversity score, and high consumption of animal source foods during the reference period. Otherwise, they were defined as "inappropriate." A Poisson regression model with robust variance estimation was used to investigate the association of the independent variables with the dietary practice. An adjusted prevalence ratio with a 95% confidence interval was reported to show an association using a p-value < 0.05. RESULTS: The appropriate dietary practice among the study participants was 15.2% (95% CI = 12-18%). Of the respondents, 29.46, 37.5, and 24.7% had a high dietary diversity, high food variety score, and high consumption of animal source foods. The appropriate dietary practice was more prevalent among merchant women (APR = 2.07; 95% CI 1.07-4.02) and those whose husbands have at least a high school educational level (APR = 1.96; 95% CI 1.06-3.46). However, the prevalence of appropriate dietary practice was significantly lower among those who chewed khat (APR = 0.58; 95% CI 0.37-0.90) and among respondents who reported restriction of the intake of some foods (APR = 0.36; 95% CI 0.20-0.65). CONCLUSION: We found sup-optimal appropriate dietary practice among pregnant women in this predominantly rural setting. Additionally, the lower appropriate dietary practice was observed among women who reported chewing khat and experienced restriction of dietary consumption during pregnancy. Therefore, nutrition policy programs and interventions aimed at encouraging maternal nutritional guidance and counseling are recommended.

Do Children with Autism Spectrum Disorders Eat Differently and Less Adequately than Those with Subclinical ASD and Typical Development? EPINED Epidemiological Study.

Food consumption in children with ASD, subclinical ASD and with typical development (TD), and their adequacy to dietary recommendations was studied. A school population sample of 77 children with ASD, 40 with subclinical ASD, and 333 with TD participated. Compared to children with TD, pre-schoolers with ASD consumed fewer raw vegetables and less fish and eggs, while primary school children consumed fewer legumes, raw vegetables, citrus fruits, cheese/yogurt and olive oil, and more meat. All groups consumed an excess of sugar but those with ASD consumed even a greater amount than their peers. The higher prevalence of obesity found in primary school children with ASD may be the consequence of a less healthy eating pattern sustained over time.

Is eating a mixed diet better for health and survival?: A systematic review and meta-analysis of longitudinal observational studies.

The role of dietary diversity in chronic disease or survival is controversial. This meta-analysis quantified the health impact of dietary diversity. Random-effects models pooled risk ratios (RRs) and 95% confidence intervals (CIs) of 20 longitudinal studies. Total dietary diversity was associated with a 22% lower risk of all-cause mortality (RR 0.78 [95%CI: 0.64, 0.96]), and was inversely associated with incident cancer- or CVD-specific mortality only in subgroup analyses (RR range: 0.53 to 0.90, p < 0.05). Similarly, diversity across healthy foods was inversely associated with all-cause mortality (RR 0.84 [95%CI: 0.73, 0.96]). An inverse association between total diet diversity and incident CVD was significant in non-European populations consuming diets with diverse food groups (RR: 0.93 [95% CI: 0.86-0.99]). Effects on cancer risk are unstudied. Diversity within fruits and/or vegetables showed null associations for all outcomes, except potentially for squamous cell-type carcinomas. More robust research is warranted. Findings indicated greater dietary diversity may benefit overall survival.

Diet diversity of urban households in India during the COVID-19 lockdown.

Background: The nature of the COVID-19 pandemic forced several nations to impose country-wide lockdowns. The lockdown impacted several aspects of life including the economy. Food security became a growing concern for many households. Aim: The aim of the study was to explore the diet diversity of urban households in India during the nationwide COVID-19 lockdown. Methods: Information regarding socioeconomic status (SES), family size and information regarding availability and access to food were gathered from 450 households. Diet diversity was assessed using a 69-item food frequency questionnaire. Food variety scores (FVS) were computed for individual food groups and overall. Results: The majority of the households (86.4%) belonged to the upper-middle or upper SES. Households did not experience any constraints in accessibility and availability of food except the meat group. Overall, 84% of the households had low FVS for most of the food groups except for sugar and milk and milk products. The household SES score was positively associated with the milk FVS (B = 0.039, p = 0.020) and negatively with the fat FVS (B = -0.062, p < 0.001). The number of adults (B = 6.773, p < 0.001) in the household positively predicted the FVS of cereal, vegetable, fruit, fat and total FVS. Conclusions: The higher SES households in urban India did not experience food insecurity. Despite this, their poor diet diversity is a serious cause for concern, especially in the wake of the evolving pandemic. This highlights the need to promote consumption of a diverse variety of foods.

Multi-component food-items and eating behaviour: What do we know and what do we need to know?

Multi-component food-items are single food products that comprise more than one food class, brought together usually via some form of processing. Importantly, individual components of the food-item remain discernible and sensorially distinguishable from each other (e.g., chocolate chip cookies or 'choc ice'). Despite a sizable research literature on the formulation of such products, there lacks a concomitant research literature on the effect(s) of multi-component food-items (compared to single component food-items) on eating behaviour. Considerable previous research has investigated the effect of multiple separate food items on food intake, portion size selection and palatability. However, studies rarely use test foods that capture the physical or chemical interactions between components that are characteristic of multi-component foods. Nevertheless, previous research and relevant theory allow us to generate hypotheses about how multi-component foods may affect eating behaviour; consideration of food variety and perceived sensory complexity suggest that consumption of multi-component foods are likely to increase perceived palatability of such foods, self-selected portion size and food intake. Moreover, many (but not all) multi-component foods would be considered ultra-processed, which is a driver of food intake in and of itself. One possibility is that food components brought together as part of a multi-component food-item interact to strongly drive eating behaviour. To explore this idea, researchers will need to work across disciplines to address various practical and methodological barriers including the technical preparation of test foods.

Evaluating a novel dietary diversity questionnaire to assess dietary diversity and adequacy of New Zealand women.

OBJECTIVES: We sought to develop and evaluate the relative validity of a dietary diversity questionnaire (DDQ) that reflects food-group diversity, food variety, and micronutrient adequacy among New Zealand women. METHODS: A cross-sectional study included New Zealand women (Auckland based; ages 16-45 y, n = 101), completing a 7-d DDQ and 4-d weighed food record (reference method). The relative validity of the DDQ was evaluated by correlating nutritious and discretionary dietary diversity scores (DDSs; number of food groups) and food-variety scores (number of foods), calculated from both methods. The dietary mean adequacy ratio (MAR; micronutrient intakes relative to estimated average requirements) was calculated from the weighed food record and correlated to dietary diversity and food-variety scores from the DDQ to assess construct validity. Cross-tabulation was used to explore dietary diversity measures versus adequacy ratios. Significance was set at P < 0.05. RESULTS: The median (interquartile range) DDSs (maximum 25) from the DDQ-23 (21-23)-and the weighed food record-18 (17-19)-were significantly correlated (rs = 0.33, P < 0.001), as were the food-variety scores (maximum 237)-respectively, 75 (61-87) and 45 (37-52) (rs = 0.22, P < 0.03). A mean (± SD) MAR of 0.94 ± 0.04 suggested a near-adequate diet, but one-third of foods consumed were from discretionary sources. Nutritious DDS was significantly correlated with MAR for micronutrients (rs = 0.20, P ≤ 0.05). An inverse trend was observed between discretionary DDS and MAR. CONCLUSIONS: The DDQ is a quick, low-burden tool for describing nutritious and discretionary dietary diversity reflecting micronutrient adequacy in high-income settings. It requires further validation across different time frames, population groups, and settings.

Dietary Pattern Accompanied with a High Food Variety Score Is Negatively Associated with Frailty in Older Adults.

Proper nutrition is a modifiable factor in preventing frailty. This study was conducted to identify the association between dietary patterns and frailty in the older adult population. The cross-sectional analysis was performed on 4632 subjects aged ≥65 years enrolled in the Korea National Health and Nutrition Examination Survey from 2014-2018. Food variety score (FVS) was defined as the number of foods items consumed over a day. Three dietary patterns were identified using factor analysis: "white rice and salted vegetables," "vegetables, oils, and fish," and "noodles and meat." The higher "white rice and salted vegetables" pattern score was related to significantly lower FVS, whereas higher "vegetables, oils, and fish" and "noodles and meat" pattern scores were associated with a higher FVS. Participants with higher FVS showed a low risk of frailty (odds ratio (OR) (95% confidence interval, CI) = 0.44 (0.31-0.61), p-trend = 0.0001) than those with lower FVS. Moreover, the "vegetables, oils, and fish" pattern score was significantly associated with a low risk of frailty (OR (95% CI) = 0.55 (0.40-0.75), p-trend = 0.0002). These results suggested that consuming a dietary pattern based on vegetables, oils, and fish with high FVS might ameliorate frailty in older adults.

Sensory-specific satiety, the variety effect and physical context: Does change of context during a meal enhance food intake?

Food variety has been shown to increase food intake, and sensory-specific satiety (a relative decrease in pleasantness of a food as it is consumed) has been proposed as the mechanism through which variety increases consumption. The aim of this study was to investigate whether variation of eating context can add to experienced meal variety and hence increase consumption even further. A total of 128 participants were assigned to one of four conditions in which they first ate a specific food item (ad libitum) until satiated, after which they consumed a second course ad libitum of either the same or a different food in either the same context or in a different context. We hypothesized that, compared to eating the same food in the same context during the second course, introducing a different food item or changing the context for the second course increases consumption (of the second course), and changing both food and context enhances food intake to a greater degree than only changing the food or changing the context. Results indicated that food variety (introducing a different food) significantly increased consumption in the second course, but that a context switch did not enhance consumption. These results suggest that there is little reason to believe that sensory-specific satiety is context specific.

[Trajectories of Dietary Variety Score among community-dwelling older Japanese and their related factors].

AIM: To categorize the age-related trajectories of dietary variety score (DVS) in the community-dwelling elderly and to examine the associated factors. METHODS: The study population included 1,195 people who underwent a medical checkup for the elderly in Kusatsu-town, Gunma Prefecture in 2012 to 2017. A multinomial logistic regression analysis was performed to examine the factors associated with the age-related trajectories of DVS. The dependent variables were sex, age, family structure, years of education, BMI, subjective chewing ability, TMIG-IC, GDS-15, MMSE, smoking, alcohol consumption, and history of hypertension, dyslipidemia, diabetes mellitus, and stroke. RESULTS: The adjusted odds ratio (95% confidence intervals) of the low trajectory group in comparison to the medium trajectory group were 2.69 (1.02-7.08) for subjective chewing ability (no chewing), 1.11 (1.06-1.17) for GDS-15, 1.76 (1.14-2.73) for current smoking, and 1.70 (1.19-2.43) for past smoking. In contrast, the adjusted odds ratio of the high trajectory group in comparison to the medium trajectory group were 0.61 (0.37-1.00) for men, 1.04 (1.01-1.07) for age, 0.58 (0.38-0.89) for subjective masticatory ability (difficult to chew), 0.88 (0.82-0.96) for GDS-15, and 0.55 (0.37-0.83) for a history of hypertension. CONCLUSIONS: The age-related trajectory patterns of DVS in the community-dwelling elderly can be categorized into three types. In order to maintain a high quality of food intake, it was shown that, in addition to subjective masticatory ability and mental health factors, such as depression, we should pay attention to the control of hypertension, which is a risk factor for lifestyle diseases, and lifestyle habits such as smoking.

The role of dietary diversity in preventing metabolic-related outcomes: Findings from a systematic review.

Dietary diversity has been linked to insulin resistance; however, studies are inconsistent on whether dietary diversity protects against metabolic-related outcomes. We aimed to comprehensively assess metabolic-related outcomes of greater diversity across the diet and within major food groups. A systematic search of peer-reviewed literature was done in bibliographic databases (Medline, Scopus, and Web of Science) for longitudinal studies that reported on original research. Data extraction and quality appraisal used predefined criteria; reported findings were synthesized through a narrative approach. Fourteen studies were identified as eligible. Greater dietary diversity across major food groups, and diversity within fruits and/or vegetables, was associated with reduced risk of type 2 diabetes (T2D). Effects varied based on exposure definition and adjustment for known confounders. While diversity of less healthy foods was associated with greater adiposity, diversity of all foods and healthy foods was associated with reduced incidence of depression and cognitive decline. Evidence supports the protective effect of dietary diversity against cognitive decline and T2D. The association between dietary diversity and adiposity may be dependent on the healthiness of foods. Public health efforts to prevent metabolic-related diseases should include an emphasis on a varied diet as a healthy eating strategy.

Effect of food variety on intake of a meal: a systematic review and meta-analysis.

BACKGROUND: Many studies have shown that food variety-the presence of multiple foods and/or sensory characteristics within and across meals-increases intake. However, studies report mixed findings, and effect size remains unclear. OBJECTIVES: A systematic review and meta-analysis were conducted to 1) synthesize data across experimental studies that examined effects of variety on total meal intake, relative to a control condition with comparatively less variety; 2) quantify support for this effect; and 3) assist in the identification of important moderating factors (registration: CRD42019153585). METHODS: In November 2019, we searched the following databases for relevant experimental studies, published in English from 1980, with human participants: PubMed, Cochrane Library, Web of Science, ClinicalTrials.gov, PsycINFO, and OpenGrey. This search was updated in September 2020. Means, standard deviations, and sample sizes were extracted from included articles, and Hedges' g was used to calculate effect sizes. Risk of bias was assessed using the Cochrane Collaboration's tool. RESULTS: Of 7259 references identified in an initial search, 34 articles consisting of 37 studies contained sufficient information for review, and data from 30 studies (39 comparisons) were included in the meta-analysis. Results from a random-effects model showed a significant small to medium effect of variety on intake (in weight and energy), with greater variety being associated with increased consumption (Hedges' g = 0.405; 95% CI: 0.259, 0.552). However, heterogeneity was considerable across studies (I2 = 84%), and this was unexplained by subgroup analyses based on form of variety, test foods, sensory characteristics, age, sex, and body weight. CONCLUSIONS: Our findings support the conclusion that variety is a robust driver of food intake. However, risk of bias was high across studies, and this review highlights methodologic limitations of studies. It is recommended that further attention is given to the development of preregistered, well-powered randomized controlled studies in eating behavior research.