Are postprandial glucose responses sufficiently person-specific to use in personalized dietary advice? Design of the RepEAT study: a fully controlled dietary intervention to determine the variation in glucose responses.

Introduction: An elevated postprandial glucose response is associated with an increased risk of cardiometabolic diseases. Existing research suggests large heterogeneity in the postprandial glucose responses to identical meals and food products between individuals, but the effect of other consumed meals during the day and the order of meals during the day on the heterogeneity in postprandial glucose responses still needs to be investigated. In addition, the robustness of the glucose responses to meals or foods is still unknown. Objectives: The overall aim of the project is to assess whether the glucose response to a meal is sufficiently person-specific to use in personalized dietary advice. We aim to answer the question: "How replicable are glucose responses to meals within individuals and how consistent is the variation in glucose responses between individuals?" Methods: The question will be assessed under standardized conditions of a 9-week fully controlled dietary intervention in which all meals are the same between individuals and consumed in a fixed order at a fixed time. 63 apparently healthy men and women with a BMI of 25-40 kg/m2 and aged 45-75 years were enrolled in the RepEAT study (NCT05456815), of whom 53 participants completed the study. The RepEAT study comprised a fully controlled dietary intervention of nine weeks, consisting of three repetitive periods of three weeks. Within each three-week period, a variety of meals and food products were offered during breakfast, lunch, dinner and in between meal snacks. Throughout the dietary intervention, glucose was continuously monitored using Freestyle Libre Pro IQ monitors. Physical activity was monitored using the ActiGraph and ActivPAL. To measure the association between glucose responses and an individual's phenotype, various measurements were performed before the start of the dietary intervention including an oral glucose tolerance test, a high-fat mixed meal challenge, assessment of body fat distribution including liver fat (MRI/MRS), and cardiometabolic markers. Discussion: The repetitive and fully controlled nature of the dietary study allows detailed assessment of the replicability of the glucose responses to meals and food products within individuals. Furthermore, the consistency of the variation between individuals independent of insulin resistance will be determined.

Incorporating Consumers' Needs in Nutrition Apps to Promote and Maintain Use: Mixed Methods Study.

BACKGROUND: Nutrition apps seem to be promising tools for supporting consumers toward healthier eating habits. There is a wide variety of nutrition apps available; however, users often discontinue app use at an early stage before a permanent change in dietary behavior can be achieved. OBJECTIVE: The main objective of this study was to identify, from both a user and nonuser perspective, which functionalities should be included in nutrition apps to increase intentions to start and maintain use of these apps. A secondary objective was to gain insight into reasons to quit using nutrition apps at an early stage. METHODS: This study used a mixed methods approach and included a qualitative and a quantitative study. The qualitative study (n=40) consisted of a home-use test with 6 commercially available nutrition apps, followed by 6 focus group discussions (FGDs) to investigate user experiences. The quantitative study was a large-scale survey (n=1420), which was performed in a representative sample of the Dutch population to quantify the FGDs' results. In the survey, several app functionalities were rated on 7-point Likert scales ranging from 1 (very unimportant) to 7 (very important). RESULTS: A total of 3 different phases of app use, subdivided into 10 user-centric app aspects and 46 associated app functionalities, were identified as relevant nutrition app elements in the FGDs. Relevance was confirmed in the survey, as all user-centric aspects and almost all app functionalities were rated as important to include in a nutrition app. In the starting phase, a clear introduction (mean 5.45, SD 1.32), purpose (mean 5.40, SD 1.40), and flexible food tracking options (mean 5.33, SD 1.45) were the most important functionalities. In the use phase, a complete and reliable food product database (mean 5.58, SD 1.41), easy navigation (mean 5.56, SD 1.36), and limited advertisements (mean 5.53, SD 1.51) were the most important functionalities. In the end phase, the possibility of setting realistic goals (mean 5.23, SD 1.44), new personal goals (mean 5.13, SD 1.45), and continuously offering new information (mean 4.88, SD 1.44) were the most important functionalities. No large differences between users, former users, and nonusers were found. The main reason for quitting a nutrition app in the survey was the high time investment (14/38, 37%). This was also identified as a barrier in the FGDs. CONCLUSIONS: Nutrition apps should be supportive in all 3 phases of use (start, use, and end) to increase consumers' intentions to start and maintain the use of these apps and achieve a change in dietary behavior. Each phase includes several key app functionalities that require specific attention from app developers. High time investment is an important reason to quit nutrition app use at an early stage.

Food waste in time of COVID-19: The heterogeneous effects on consumer groups in Italy and the Netherlands.

Since COVID-19 outbreak, States adopted different combinations of measures to restrain its spread that affected individual behaviors and the already fragile local and global food systems. The aim of this research is to contribute to the scientific debate around food systems sustainability through the analysis of behavioral shifts in household food waste drivers, specifically occurring during the recent global pandemic. A survey was developed based on an extended version of the Motivation-Opportunity-Ability (MOA) approach. A representative sample of 3000 respondents in Italy and in the Netherlands (1500 per country) completed this survey in May 2020, while lockdown to mitigate the first wave of COVID-19 outbreak was active in both countries. A cluster analysis based on individual food-waste- related behaviors identified four homogenous groups of consumers in the Italian sample and five in the Dutch sample. The comparative analysis of these groups led to the identification of several communalities in behavioral patterns, both within and between the two countries. Results suggest that in both countries, self-reported quantities of household food waste actually decreased, with a stronger reduction reported by Italian consumers. The MOA approach allowed to explain this perceived reduction as largely depending on the increase of opportunity to dedicate more time - to food-related activities as compared to the pre-COVID-19 period, with positive consequences on food management ability. These findings assist in drafting recommendations for tailored interventions to reduce the amount of domestic food waste and preserve positive behaviors emerged during lockdown, that could be continued in the absence of crisis.

Influence of oral processing behaviour and bolus properties of brown rice and chickpeas on in vitro starch digestion and postprandial glycaemic response.

PURPOSE: Oral processing behaviour may contribute to individual differences in glycaemic response to foods, especially in plant tissue where chewing behaviour can modulate release of starch from the cellular matrix. The aim of this study was to assess the impact of chewing time of two starch based foods (brown rice and chickpeas) on bolus properties, in vitro starch digestion and postprandial glycaemic excursion in healthy subjects. METHODS: In a cross-over trial participants (n = 26) consumed two carbohydrates-identical test meals (brown rice: 233 g; chickpeas: 323 g) with either long (brown rice: 41 s/bite; chickpeas: 37 s/bite) or short (brown rice: 23 s/bite; chickpeas: 20 s/bite) chewing time in duplicate while glycaemic responses were monitored using a continuous glucose monitoring device. Expectorated boli were collected, then bolus properties (number, mean area, saliva amylase activity) and in vitro starch digestion were determined. RESULTS: Longer chewing resulted in significantly (p < 0.05) more and smaller bolus particles, higher bolus saliva uptake and higher in vitro degree of intestinal starch hydrolysis (DH_Schewing time%) than shorter chewing for both foods (brown rice: DH_S%23 s = 84 ± 4% and DH_%S41s = 90 ± 6%; chickpeas: DH_S%20 s = 27 ± 3% and DH_%S37s = 34 ± 5%, p < 0.001). No significant effect of chewing time on glycaemic response (iAUC) (p > 0.05) was found for both meals. Brown rice showed significantly and considerably higher in vitro degree of intestinal starch hydrolysis and glycaemic response (iAUC) than chickpeas regardless of chewing time. No significant correlations were observed between bolus properties and in vitro starch hydrolysis or glycaemic response (p > 0.05). CONCLUSION: Differences in the innate structure of starch based foods (brown rice compared to chickpeas) have a larger effect on postprandial glucose response than differences in mastication behaviour although oral processing behaviour showed consistent effects on bolus properties and in vitro starch digestion. Trial registration ClinicalTrials.gov identifier: NCT04648397 (First posted: December 1, 2020).

Daily Intake of Lemna minor or Spinach as Vegetable Does Not Show Significant Difference on Health Parameters and Taste Preference.

The growing world population will increase the demand for new sustainable foods and ingredients. Here we studied the safety and tolerance of Lemna minor, a new sustainable vegetable crop from the duckweed family. Twenty-four healthy adults consumed either L. minor plant material or spinach as vegetable (170 g fresh weight) as part of a warm meal on 11 consecutively days in a randomized controlled parallel trial design. The intervention meals had a different recipe for each day of the week. All participants had to report daily if they experienced gastric complaints, feelings of hunger, fullness, desire to eat, thirst, general health, nausea, and stool consistency. Only hunger, flatulence and constipation were significantly different between both intervention groups. At the start and end of the intervention, blood and urine were sampled in order to analyze biomarkers for general health, e.g., kidney function, liver function, cardiovascular health, inflammation and iron status. Both intervention groups did not show significant differences for these biomarkers. In taste attributes the L. minor-based products showed in only a few specific cases a significant difference compared to the spinach-based products. Based on the results we conclude that 11 consecutive days intake of 170 g fresh weight L. minor plants as a cooked vegetable does not result in any adverse effect in healthy adult subjects.

Effect of 4-Week Consumption of Soy Kori-tofu on Cardiometabolic Health Markers: A Double-Blind Randomized Controlled Cross-Over Trial in Adults with Mildly Elevated Cholesterol Levels.

Kori-tofu is a frozen soy tofu, and soy consumption is associated with positive effects on cardiometabolic health markers. We aimed to assess the potential of Kori-tofu to improve cardiometabolic health outcomes in humans by repetitive daily consumption. In a double-blind randomized controlled cross-over trial, 45 subjects aged 40-70 years with (mildly) elevated cholesterol levels, received a four week Kori-tofu intervention or whey protein control intervention with a four week wash-out period in between. Cardiometabolic biomarkers were measured before and after both interventions. A significant decrease in total, low-density lipids (LDL), and high-density lipids (HDL) cholesterol, Hemoglobin A1c (HbA1c), fructosamine and systolic blood pressure was observed within the Kori-tofu intervention. However, many of these findings were also observed in the control intervention. Only adiponectin changes were different between treatments but did not change significantly within interventions. Improvements in cardiometabolic markers within the Kori-tofu intervention point toward potential beneficial health effects. Due to the lack of significant effects as compared to control, there is, however, currently no substantiating evidence to claim that Kori-tofu has beneficial effects on cardiometabolic health.

Exploring the Potential of Personalized Dietary Advice for Health Improvement in Motivated Individuals With Premetabolic Syndrome: Pretest-Posttest Study.

BACKGROUND: Dietary quality plays an essential role in the prevention and management of metabolic syndrome (MetS). OBJECTIVE: The aim of this pilot study is to organize personalized dietary advice in a real-life setting and to explore the effects on dietary intake, metabolic health, and perceived health. METHODS: We followed a one-group pretest-posttest design and included 37 individuals at risk of MetS, who indicated motivation to change dietary behavior. For a period of 16 weeks, participants received personalized advice (t=0 and t=8) and feedback (t=0, t=4, t=8, t=12 and t=16) on dietary quality and metabolic health (ie, waist circumference, BMI, blood pressure, lipid profile, fasting glucose levels, and C-peptide). Personalized advice was generated in a two-stage process. In stage 1, an automated algorithm generated advice per food group, integrating data on individual dietary quality (Dutch Healthy Diet Index; total score 8-80) and metabolic health parameters. Stage 2 included a telephone consultation with a trained dietitian to define a personal dietary behavior change strategy and to discuss individual preferences. Dietary quality and metabolic health markers were assessed at t=0, t=8, and t=16. Self-perceived health was evaluated on 7-point Likert scales at t=0 and t=16. RESULTS: At the end of the study period, dietary quality was significantly improved compared with the baseline (Dutch Healthy Diet Index +4.3; P<.001). In addition, lipid profile (triglycerides, P=.02; total cholesterol, P=.01; high-density lipoprotein, P<.001; and low-density lipoprotein, P<.001), BMI (P<.001), waist circumference (P=.01), and C-peptide (P=.01) were all significantly improved, whereas plasma glucose increased by 0.23 nmol/L (P=.04). In line with these results, self-perceived health scores were higher at t=16 weeks than at baseline (+0.67; P=.005). CONCLUSIONS: This exploratory study showed that personalized dietary advice resulted in positive effects on dietary behavior, metabolic health, and self-perceived health in motivated pre-MetS adults. The study was performed in a do-it-yourself setting, highlighting the potential of at-home health improvement through dietary changes. TRIAL REGISTRATION: ClinicalTrials.gov NCT04595669; https://clinicaltrials.gov/ct2/show/NCT04595669.

Strategies to increase primary school children's fruit and vegetable intake during 10AM snack time.

In this observational study, children's fruit and vegetable (F&V) consumption during the 10AM school break was assessed for two promising strategies: a 5-day-a-week F&V policy and free provision of F&V presented in an attractive fruit bowl. Schools without a school food policy served as reference group. A secondary aim was to explore the feasibility of the two strategies. A total of 569 children aged 6-9 years participated. Children's F&V consumption at school was assessed on two different week days via observations and weighing snack portions. Parents completed an online-questionnaire on their perceptions and experiences with the two strategies. Main outcomes were the proportion of children and frequency of eating F&V, and children's F&V portion sizes. Data were analysed via ANOVA and Chi-Square (p < 0.05). Average F&V consumption differed significantly between the three situations (p < 0.001): 250 g in the fruit bowl situation, 130 g in the 5-day-policy situation and 60 g in the no-policy situation. The proportion of children eating F&V was high for the 5-day-policy (97-98%) and fruit bowl situation (87-97%), whereas this was substantially lower (50-60%; p < 0.001) in the no-policy situation. The majority of parents considered both strategies as feasible. A 5-day-a-week F&V policy seems an effective, feasible and structural strategy to support children's fruit and vegetable consumption at school. The fruit bowl strategy with an additional eating moment may enhance children's intake even further, although additional requirements are needed for structural implementation at school.