Meta-Analysis of Randomized Controlled Trials of Red Meat Consumption in Comparison With Various Comparison Diets on Cardiovascular Risk Factors.

BACKGROUND: Findings among randomized controlled trials evaluating the effect of red meat on cardiovascular disease risk factors are inconsistent. We provide an updated meta-analysis of randomized controlled trials on red meat and cardiovascular risk factors and determine whether the relationship depends on the composition of the comparison diet, hypothesizing that plant sources would be relatively beneficial. METHODS: We conducted a systematic PubMed search of randomized controlled trials published up until July 2017 comparing diets with red meat with diets that replaced red meat with a variety of foods. We stratified comparison diets into high-quality plant protein sources (legumes, soy, nuts); chicken/poultry/fish; fish only; poultry only; mixed animal protein sources (including dairy); carbohydrates (low-quality refined grains and simple sugars, such as white bread, pasta, rice, cookies/biscuits); or usual diet. We performed random-effects meta-analyses comparing differences in changes of blood lipids, apolipoproteins, and blood pressure for all studies combined and stratified by specific comparison diets. RESULTS: Thirty-six studies totaling 1803 participants were included. There were no significant differences between red meat and all comparison diets combined for changes in blood concentrations of total, low-density lipoprotein, or high-density lipoprotein cholesterol, apolipoproteins A1 and B, or blood pressure. Relative to the comparison diets combined, red meat resulted in lesser decreases in triglycerides (weighted mean difference [WMD], 0.065 mmol/L; 95% CI, 0.000-0.129; P for heterogeneity <0.01). When analyzed by specific comparison diets, relative to high-quality plant protein sources, red meat yielded lesser decreases in total cholesterol (WMD, 0.264 mmol/L; 95% CI, 0.144-0.383; P<0.001) and low-density lipoprotein (WMD, 0.198 mmol/L; 95% CI, 0.065-0.330; P=0.003). In comparison with fish, red meat yielded greater decreases in low-density lipoprotein (WMD, -0.173 mmol/L; 95% CI, -0.260 to -0.086; P<0.001) and high-density lipoprotein (WMD, -0.065 mmol/L; 95% CI, -0.109 to -0.020; P=0.004). In comparison with carbohydrates, red meat yielded greater decreases in triglycerides (WMD, -0.181 mmol/L; 95% CI, -0.349 to -0.013). CONCLUSIONS: Inconsistencies regarding the effects of red meat on cardiovascular disease risk factors are attributable, in part, to the composition of the comparison diet. Substituting red meat with high-quality plant protein sources, but not with fish or low-quality carbohydrates, leads to more favorable changes in blood lipids and lipoproteins.

Environmental and Economic Effects of Changing to Shelf-Stable Dairy or Soy Milk for the Breakfast in the Classroom Program.

OBJECTIVES: To estimate economic and environmental effects of reducing milk waste from the US Breakfast in the Classroom (BIC) School Breakfast Program by replacing conventional milk with shelf-stable dairy or soy milk. METHODS: We estimated net greenhouse gas emissions (GHGE; kg CO2 equivalents [e]) from replacing conventional milk with shelf-stable dairy or soy milk by adapting existing life cycle assessments and US Environmental Protection Agency Waste Reduction Model estimates to BIC parameters. We estimated net cost with school meal purchasing data. RESULTS: Replacing conventional dairy milk with shelf-stable dairy or soy milk would reduce milk-associated GHGE by 28.5% (0.133 kg CO2e) or 79.8% (0.372 kg CO2e) per student per meal, respectively. Nationally, this equates to driving 248 million or 693 million fewer miles annually, respectively. This change would increase milk costs 1.9% ($0.005) or 59.4% ($0.163) per student per meal, respectively. CONCLUSIONS: Replacing conventional milk with shelf-stable dairy or soy milk could substantially reduce waste and concomitant GHGE in BIC; switching to shelf-stable dairy has low net costs. Pilot tests of these options are warranted to optimize the nutritional value, cost, and sustainability of BIC.

Nutritional, Economic, and Environmental Costs of Milk Waste in a Classroom School Breakfast Program.

OBJECTIVES: To measure fluid milk waste in a US School Breakfast in the Classroom Program and estimate its nutritional, economic, and environmental effects. METHODS: Fluid milk waste was directly measured on 60 elementary school classroom days in a medium-sized, urban district. The US Department of Agriculture nutrition database, district cost data, and carbon dioxide equivalent (CO2e) emissions and water footprint estimates for fluid milk were used to calculate the associated nutritional, economic, and environmental costs. RESULTS: Of the total milk offered to School Breakfast Program participants, 45% was wasted. A considerably smaller portion of served milk was wasted (26%). The amount of milk wasted translated into 27% of vitamin D and 41% of calcium required of School Breakfast Program meals. The economic and environmental costs amounted to an estimated $274 782 (16% of the district's total annual School Breakfast Program food expenditures), 644 893 kilograms of CO2e, and 192 260 155 liters of water over the school year in the district. CONCLUSIONS: These substantial effects of milk waste undermine the School Breakfast Program's capacity to ensure short- and long-term food security and federal food waste reduction targets. Interventions that reduce waste are urgently needed.

School staff, parent and student perceptions of a Breakfast in the Classroom model during initial implementation.

OBJECTIVE: To understand perspectives of stakeholders during initial district-wide implementation of a Breakfast in the Classroom (BIC) model of the School Breakfast Program. DESIGN: Qualitative data were collected from twenty-nine focus groups and twenty interviews with stakeholders in a school district early in the process of implementing a BIC model of the School Breakfast Program. SETTING: Ten elementary schools within a large, urban school district in the USA that served predominantly low-income, racial/ethnic minority students. SUBJECTS: Purposively selected stakeholders in elementary schools that had implemented BIC for 3-6 months: students (n 85), parents/guardians (n 86), classroom teachers (n 44), cafeteria managers (n 10) and principals (n 10). RESULTS: Four primary themes emerged, which were interpreted based on the Diffusion of Innovations model. School staff had changed their perceptions of both the relative disadvantages and costs related to time and effort of BIC over time; the majority of each stakeholder group expressed an appreciation for BIC; student breakfast consumption varied from day to day, related to compatibility of foods with child preferences; and stakeholders held mixed and various impressions of BIC's potential impacts. CONCLUSIONS: The study underscores the importance of engaging school staff and parents in discussions of BIC programming prior to its initiation to pre-emptively address concerns related to cost, relative disadvantages and compatibility with child preferences and school routines/workflow. Effectively communicating with stakeholders about positive impacts and nutritional value of the meals may improve support for BIC. These findings provide new information to policy makers, districts and practitioners that can be used to improve implementation efforts, model delivery and outcomes.

'It's just so much waste.' A qualitative investigation of food waste in a universal free School Breakfast Program.

OBJECTIVE: To understand stakeholders' perspectives on food waste in a universal free School Breakfast Program implementing a Breakfast in the Classroom model. DESIGN: Semi-structured focus groups and interviews were conducted with school district stakeholders. Inductive methods were used to code resulting transcripts, from which themes were identified. The analysis provides a thematic analysis of stakeholders' perspectives on food waste in the School Breakfast Program. SETTING: Ten elementary schools in a large urban school district implementing a universal free Breakfast in the Classroom model of the US national School Breakfast Program. SUBJECTS: Elementary-school students (n 85), parents (n 86), teachers (n 44), cafeteria managers (n 10) and school principals (n 10). RESULTS: Stakeholders perceived food waste as a problem and expressed concern regarding the amount of food wasted. Explanations reported for food waste included food-related (palatability and accessibility), child-related (taste preferences and satiation) and programme-related (duration, food service policies, and coordination) factors. Milk and fruit were perceived as foods particularly susceptible to waste. Several food waste mitigation strategies were identified by participants: saving food for later, actively encouraging children's consumption, assisting children with foods during mealtime, increasing staff support, serving smaller portion sizes, and composting and donating uneaten food. CONCLUSIONS: Stakeholders recognized food waste as a problem, reported myriad contributing factors, and have considered and employed multiple and diverse mitigation strategies. Changes to the menu and/or implementation logistics, as well as efforts to use leftover food productively, may be possible strategies of reducing waste and improving the School Breakfast Program's economic, environmental and nutritional impact.

Food Waste Management Practices and Barriers to Progress in U.S. University Foodservice.

Identifying institutional capacity to reduce and reallocate food waste is important to reduce both greenhouse gas emissions and food insecurity. The goal of this study was to examine food waste concern, reduction and repurposing strategies, and perceived barriers to these strategies among U.S. university foodservice representatives. We surveyed 57 U.S. university foodservice representatives about foodservice operations, campus food insecurity, food waste reduction and repurposing activities, and obstacles to composting and donating food waste. Data were collected September 2019-February 2020. Roughly three-quarters of respondents tracked campus food waste, reported that food waste reduction was a high/very high priority, and reported concern about campus food insecurity. The most common food-waste-reduction strategies included forecasting demand to prevent overproduction and preparing smaller batches. The most common repurposing strategies included donation and composting. Top barriers to food donation included liability concerns and lack of labor. Barriers to composting food included lack of infrastructure and knowledge/experience. Addressing perceived barriers to university foodservices' food waste reduction and repurposing efforts could lead to reduced greenhouse gas emissions and improved food security for millions of Americans.

Health and environmental impacts of plant-rich dietary patterns: a US prospective cohort study.

BACKGROUND: Diets that are rich in animal-based foods threaten planetary and human health, but plant-rich diets have varied health and environmental effects. We aimed to characterise a healthy dietary index and three plant-based indices by their environmental impacts and associations with risk of cardiovascular disease. METHODS: In this prospective cohort study, we used data from a food-frequency questionnaire in the US-based Nurses' Health Study II. Participants were categorised by quintiles of four dietary indices, including the alternative healthy eating index-2010 (AHEI), plant-based diet index (PDI), unhealthy PDI, and healthy PDI. We calculated environmental impacts (greenhouse gas emissions and irrigation water, nitrogenous fertiliser, and high-quality cropland needs), and relative risks (RRs) of cardiovascular disease from 1991-2017, comparing quintiles. FINDINGS: We included 90 884 participants in the health-impact analysis and 65 625 participants in the environmental-impact analysis. Comparing the top and bottom quintiles, higher AHEI scores were associated with a decreased cardiovascular disease risk (relative risk 0·77 [95% CI 0·66-0·89]); 30% lower greenhouse gas emissions (Q5 2·6 kg CO2 equivalent vs Q1 3·7 kg CO2 equivalent); and lower fertiliser, cropland, and water needs (all ptrends<0·0001). Similarly, the highest healthy PDI and PDI quintiles were associated with a decreased cardiovascular disease risk (healthy PDI 0·71 [0·60-0·83] and PDI 0·74 [0·63-0·85]) and lower environmental impacts (PDI water needs ptrend=0·0014; all other ptrends<0·0001). Conversely, the highest unhealthy PDI quintile had a higher cardiovascular disease risk compared with the lowest unhealthy PDI quintile (1·15 [1·00-1·33]; ptrend=0·023) and required more cropland (ptrend<0·0001) and fertiliser (ptrend=0·0008). INTERPRETATION: Dietary patterns that are associated with better health had lower greenhouse gas emissions and nitrogenous fertiliser, cropland, and irrigation water needs. Not all plant-based diets conferred the same health and environmental benefits. US dietary guidelines should include nuanced consideration of environmental sustainability. FUNDING: US National Institutes of Health.

Processed and Packed: How Refined Are the Foods That Children Bring to School for Snack and Lunch?

BACKGROUND: Increasing consumption of highly processed foods has been associated with adverse health outcomes among children. In the US, children consume up to half of their daily energy intake at school. OBJECTIVES: We sought to characterize foods that children bring from home to school according to processing level and to evaluate the effectiveness of a school-based intervention, Great Taste Less Waste (GTLW), in reducing the proportion of energy brought from highly processed foods from home compared with control. DESIGN: Secondary data analysis of a 7-month school-based, cluster-randomized trial. PARTICIPANTS/SETTING: Third- and fourth-grade students (n = 502, mean age: 9.0 ± 0.62 years) at 10 public elementary schools in Eastern Massachusetts (school year 2012-2013). INTERVENTION: GTLW included a 22-lesson classroom curriculum, homework activities, monthly parent newsletters, a food shopping and packing guide for parents, food demonstrations, school-wide announcements, and a poster contest. MAIN OUTCOME MEASURES: The energy content of foods brought to school was estimated from digital photographs, and foods were assigned to 1 of 3 processing levels (less processed or unprocessed, moderately processed, or highly processed) based on an established classification system. STATISTICAL ANALYSES PERFORMED: The percentage of energy brought from foods categorized into each processing level was calculated and compared pre- and postintervention using hierarchical linear models. RESULTS: Most of the food brought from home to school was highly processed (70% of food energy brought). Foods categorized as snack foods and desserts contributed the greatest percentage of total energy to the highly processed category at baseline and follow-up (72% and 69%, respectively). Energy from foods brought for snack tended to be more highly processed than those brought for lunch. No significant differences were observed from pre- to postintervention in the GTLW group compared with control for the percentage of energy brought from highly processed foods in adjusted models (ß: -1.1, standard error: 2.2, P = .6) or any other processing level. CONCLUSIONS: Highly processed foods were prevalent in home-packed lunches and snacks, and these patterns persisted after a targeted intervention. Further research is needed to identify strategies to improve the healthfulness of foods brought from home to school.

Factors Influencing Fluid Milk Waste in a Breakfast in the Classroom School Breakfast Program.

OBJECTIVE: To determine predictors of fluid milk waste in a Breakfast in the Classroom School Breakfast Program. DESIGN: Cross-sectional with 3 repeated measures/classroom. SETTING: Elementary schools in a medium-sized, low-income, urban school district. PARTICIPANTS: Twenty third- through fourth-grade classrooms across 6 schools. MAIN OUTCOMES: Dependent variables include percentage of total and served milk wasted. Independent variables included observed daily menu offerings, program factors, and teacher and student behavior. ANALYSIS: Descriptive statistics were used to characterize variables across classrooms and schools. Multilevel mixed-effects models were used to test associations between predictors and outcomes of interest. P ≤ .05 was considered statistically significant. RESULTS: Total milk waste increased 12% when juice was offered and 3% for each additional carton of unserved milk. Teacher encouragement to take and/or consume breakfast was associated with a 5% and 9% increase in total and served milk waste, respectively. When students were engaged in other activities in addition to eating breakfast, total milk waste decreased 10%. CONCLUSIONS AND IMPLICATIONS: Beverage offerings were predictive of greater total milk waste. Teacher and student behavior also appeared to influence milk consumption. Findings suggest that specific changes to School Breakfast Program implementation policies and practices could have an important role in waste mitigation.

Behavioral Correlates of Empirically-Derived Dietary Patterns among University Students.

Given the importance of young adulthood in establishing lifelong dietary habits, it is imperative to better understand potential underlying drivers of dietary behavior in the university-age population. Dietary patterns have been associated with disease risk, but behavioral predictors of dietary pattern adherence are poorly understood, especially among emerging adults. This study aims to evaluate health-related behaviors associated with dietary pattern scores among freshmen participating in the Tufts Longitudinal Health Study (TLHS; n = 630). We previously derived dietary patterns using principal components analysis and orthogonal rotation from dietary intake data. Health-related behavior data were collected via survey. All data were collected during the Spring semesters of 1998⁻2007. Unadjusted linear models were used to determine associations between dietary pattern scores and health-related behaviors. Significant correlates were retained in multivariable regression models, which were adjusted for demographic characteristics. We found that never eating meals away from home was associated with higher adherence to the Prudent and lower adherence to the Western and Alcohol patterns. Intention to lose weight was negatively associated with the Western pattern, while intention to gain weight was positively associated with all dietary patterns. These findings suggest that intervention efforts aimed at improving eating out behaviors and engaging in healthy weight management strategies may promote healthier dietary patterns among university students.

Cross-Sectional Associations between Empirically-Derived Dietary Patterns and Indicators of Disease Risk among University Students.

The transition from adolescence to adulthood is a unique period during which lifelong dietary habits are shaped. Dietary patterns (DPs) among young adults attending college have not been adequately described, and associations between DPs and indicators of disease risk are not well understood in this age group. Dietary data were collected from undergraduates participating in the Tufts Longitudinal Health Study (TLHS; 1998-2007) by Food Frequency Questionnaire (FFQ; n = 1323). DPs were derived using principal components analysis with varimax rotation. Scree plots; eigenvalues; factor loadings; and previous studies were used to determine and label the DPs retained. Cross-sectional relationships between DP scores and anthropometric measures (percent body fat (PBF) and (BMI) and lipid biomarkers (total; HDL and LDL cholesterol; and triglycerides) were assessed with multivariable regression models; adjusted for demographics; physical activity; smoking; intention to gain/lose weight; and total energy intake. Effect modification by sex was tested. Three DPs were identified: Prudent; Western; and Alcohol. Greater adherence to the Prudent DP was associated with favorable anthropometric outcomes. The Alcohol DP was associated with a favorable lipid profile. Associations between the Western DP and blood lipids differed by sex; with unfavorable impact observed only among males. Our findings add to the literature linking DPs in young adults with measurable adiposity and cardiometabolic outcomes; suggesting that improving nutrition among college students could reduce chronic disease risk.

Serum Retinol and Carotenoids in Association with Biomarkers of Insulin Resistance among Premenopausal Women.

OBJECTIVE: The aim of this study was to investigate how serum retinol and carotenoids (ß-carotene, ß-cryptoxanthin, lutein/zeaxanthin, lycopene) are associated with biomarkers of insulin resistance. RESEARCH METHODS AND PROCEDURES: The BioCycle Study (2005-2007) is a prospective cohort of 259 healthy premenopausal women. Fasting serum samples were collected at up to sixteen clinic visits, from which retinol, carotenoids, insulin, glucose, and sex hormone-binding globulin (SHBG) were measured. Insulin resistance was estimated by the homeostasis model assessment (HOMA-IR). Linear mixed models were used to determine associations adjusting for age, race, body mass index (BMI), education, smoking, physical activity, triglycerides, and energy intake. RESULTS: Retinol was positively associated with HOMA-IR (ß = 0.19 (95% CI: 0.07, 0.32)) units per ug/mL increase in retinol; the relationship was driven by insulin (ß = 0.20 (95% CI: 0.08, 0.31)). Retinol was inversely associated with SHBG (ß = -0.22 (95% CI: -0.28, -0.16)). Although no significant associations were found between serum carotenoids and HOMA-IR, ß-carotene was positively associated with SHBG and ß-cryptoxanthin inversely with fasting plasma glucose. CONCLUSION: Results indicate a possible role for serum retinol in the pathogenesis of type 2 diabetes. However, they do not support a strong association between individual or total serum carotenoids and insulin resistance.