Zach Conrad

Reducing US cardiovascular disease burden and disparities through national and targeted dietary policies: A modelling study

Background Large socio-economic disparities exist in US dietary habits and cardiovascular disease (CVD) mortality. While economic incentives have demonstrated success in improving dietary choices, the quantitative impact of different dietary policies on CVD disparities is not well established. We aimed to quantify and compare the potential effects on total CVD mortality and disparities of specific dietary policies to increase fruit and vegetable (F&V) consumption and reduce sugar-sweetened beverage (SSB) consumption in the US. Methods and findings Using the US IMPACT Food Policy Model and probabilistic sensitivity analyses, we estimated and compared the reductions in CVD mortality and socio-economic disparities in the US population potentially achievable from 2015 to 2030 with specific dietary policy scenarios: (a) a national mass media campaign (MMC) aimed to increase consumption of F&Vs and reduce consumption of SSBs, (b) a national fiscal policy to tax SSBs to increase prices by 10%, (c) a national fiscal policy to subsidise F&Vs to reduce prices by 10%, and (d) a targeted policy to subsidise F&Vs to reduce prices by 30% among Supplemental Nutrition Assistance Program (SNAP) participants only. We also evaluated a combined policy approach, combining all of the above policies. Data sources included the Surveillance, Epidemiology, and End Results Program, National Vital Statistics System, National Health and Nutrition Examination Survey, and published meta-analyses. Among the individual policy scenarios, a national 10% F&V subsidy was projected to be most beneficial, potentially resulting in approximately 150,500 (95% uncertainty interval [UI] 141,400–158,500) CVD deaths prevented or postponed (DPPs) by 2030 in the US. This far exceeds the approximately 35,100 (95% UI 31,700–37,500) DPPs potentially attributable to a 30% F&V subsidy targeting SNAP participants, the approximately 25,800 (95% UI 24,300–28,500) DPPs for a 1-y MMC, or the approximately 31,000 (95% UI 26,800–35,300) DPPs for a 10% SSB tax. Neither the MMC nor the individual national economic policies would significantly reduce CVD socio-economic disparities. However, the SNAP-targeted intervention might potentially reduce CVD disparities between SNAP participants and SNAP-ineligible individuals, by approximately 8% (10 DPPs per 100,000 population). The combined policy approach might save more lives than any single policy studied (approximately 230,000 DPPs by 2030) while also significantly reducing disparities, by approximately 6% (7 DPPs per 100,000 population). Limitations include our effect estimates in the model; these estimates use interventional and prospective observational studies (not exclusively randomised controlled trials). They are thus imperfect and should be interpreted as the best available evidence. Another key limitation is that we considered only CVD outcomes; the policies we explored would undoubtedly have additional beneficial effects upon other diseases. Further, we did not model or compare the cost-effectiveness of each proposed policy. Conclusions Fiscal strategies targeting diet might substantially reduce CVD burdens. A national 10% F&V subsidy would save by far the most lives, while a 30% F&V subsidy targeting SNAP participants would most reduce socio-economic disparities. A combined policy would have the greatest overall impact on both mortality and socio-economic disparities.

Regional self-reliance of the Northeast food system

Farms producing similar products have become increasingly concentrated geographically over the past century in the United States (US). Due to the concentration of food production, a disruption in key production areas may reduce the availability of certain foods nationwide. For example, climate change poses such a threat, with projections of altered precipitation patterns, increased temperature and pest outbreaks, which may result in reduced crop yields and geographic shifts in crop adaptation. Analyses of the degree to which US regions can satisfy the food needs of their resident populations—a concept we refer to as regional self-reliance (RSR)—are therefore warranted. We focus on the Northeast region because of its high population density and declining agricultural landbase. Our objectives are to: (1) determine how agricultural land is used in the Northeast region; (2) determine the variety and amount of foods produced; and (3) analyze the relationship between food consumption and agricultural output. Annual (2001–2010) data on land area, yield and output of all crops and major livestock categories, as well as seafood landings, were catalogued. National annual (2001–2009) data on food availability were used as a proxy for estimates of food consumption, and these data were downscaled to a regional level and compared with regional production data in order to estimate RSR. In the Northeast region, approximately 65% of land in farms contributed directly to the food supply from 2001 to 2010, although this varied significantly across states. Just over one-half of all land in farms in the region was devoted to the production of livestock feed. The region produced >100 food crops annually from 2001 to 2009, and vegetables represented the majority of food crop production by weight. Chicken accounted for the largest weight of meat products produced. Compared to the Northeast regions share (~6%) of total land in farms in the nation, it accounted for disproportionately higher amounts of the national production of dairy (16%), eggs (13%), chicken (9%), lamb (7%) and vegetables (7%). However, the region accounted for ~22% of the national population and therefore produced a disproportionately low share of food on a per capita basis. RSR for plant-based foods was lowest for pulses (7%) and highest for vegetables (26%). There are four specific factors in the RSR in our analysis, each of which could result in substantial shifts (upward or downward) of the RSR in the future: land used for agriculture, crop (or animal) productivity, population and dietary preferences.

Relationship of the Reported Intakes of Fat and Fatty Acids to Body Weight in US Adults

Dietary fat composition may modulate energy expenditure and body weight. Little is known about the relationship between fatty acid intake and body weight at a population level. The purposes of this study were to compare intakes of energy, macronutrients, and individual fatty acids across BMI categories (1) for the US adult population and, (2) by sociodemographic groups. Reported dietary intake data from the National Health and Nutrition Examination Survey (NHANES) and What We Eat in America (WWEIA) surveys in the years 2005–2012 were analyzed. Overall, we found that the reported intake of carbohydrate, protein, total fat, total saturated fat (as well as long-chain saturated fatty acids 14:0–18:0), and monounsaturated fatty acids (MUFAs) were positively associated with BMI; while lauric acid (a medium-chain saturated fatty acid, 12:0) and total polyunsaturated fatty acids (PUFAs) (as well as all individual PUFAs) were not associated with BMI. Non-Hispanic black individuals demonstrated a negative association between BMI and energy intake and a positive association between total PUFAs, linoleic acid (LA), α-linolenic acid (ALA) and BMI. Individuals with less than a high school education showed a negative association between BMI and DHA. Mexican-Americans reported intakes with no association between BMI and energy, any macronutrient, or individual fatty acids. These findings support those of experimental studies demonstrating fatty acid-dependent associations between dietary fatty acid composition and body weight. Notably, we observed divergent results for some sociodemographic groups which warrant further investigation.

Cardiometabolic Mortality by Supplemental Nutrition Assistance Program Participation and Eligibility in the United States

Objectives To investigate total and cause-specific cardiometabolic mortality among Supplemental Nutrition Assistance Program (SNAP) participants, SNAP-eligible nonparticipants, and SNAP-ineligible individuals overall and by age, gender, race/ethnicity, and other characteristics. Methods We performed a prospective study with nationally representative survey data from the National Health Interview Survey (2000-2009), merged with subsequent Public-Use Linked Mortality Files (2000-2011). We used survey-weighted Cox proportional hazards models adjusted for age and gender to estimate hazard ratios of total and cause-specific cardiometabolic mortality for 499 741 US adults aged 25 years or older. Results Over a mean of 6.8 years of follow-up (maximum 11.9 years), 39 293 deaths occurred, including 7408 heart disease, 2185 stroke, and 1376 diabetes deaths. Individuals participating in SNAP exhibited higher total and cardiovascular disease mortality, largely limited to non-Hispanic Whites and non-Hispanic Blacks, than both SNAP-eligible nonparticipants and SNAP-ineligible individuals, and higher diabetes mortality across races/ethnicities (P < .01). Conclusions Participants in SNAP require greater focus to understand and further address their poor health outcomes. Public Health Implications Low-income Americans require even greater efforts to improve their health than they currently receive, and such efforts should be a priority for public health policymakers.

Diet quality on meatless days: National Health and Nutrition Examination Survey (NHANES), 2007-2012.

OBJECTIVE To compare diet quality scores between adult non-meat eaters and meat eaters, and to compare the consumption of diet components across quintiles of diet quality. DESIGN Cross-sectional analysis. The Healthy Eating Index-2010 (HEI-2010) and Alternative Healthy Eating Index-2010 (AHEI-2010) were used to assess mean diet quality. Differences in consumption of diet components between quintiles of diet quality were tested using post hoc Wald tests and z tests. SETTING The National Health and Nutrition Examination Survey (NHANES), 2007-2012. SUBJECTS The sample consisted of 16810 respondents aged≥18 years, including 280 individuals who reported not consuming meat, poultry, game birds or seafood on two non-consecutive days of dietary recall. Dietary data were obtained from one dietary recall per individual. RESULTS Non-meat eaters had substantially greater HEI-2010 and AHEI-2010 scores than meat eaters (P<0·05). Among non-meat eaters, mean consumption across HEI-2010 quintiles demonstrated different (P<0·05) amounts of empty calories and unsaturated:saturated fatty acids. Mean consumption across AHEI-2010 quintiles demonstrated different (P<0·05) amounts of nuts and legumes, vegetables and PUFA. CONCLUSIONS Public health messages targeted at vegetarians and others who may choose to eat meat-free on certain days should emphasize decreased consumption of empty calories, and increased consumption of nuts and legumes, PUFA and vegetables, as a way to improve overall dietary quality.

Inter- and independent effects of region and race/ethnicity on variety of fruit and vegetable consumption in the USA: 2011 Behavioral Risk Factor Surveillance System (BRFSS).

OBJECTIVE (i) To estimate the independent and combined effects of race/ethnicity and region on the variety of fruits and vegetables consumed in the USA in 2011; and (ii) to assess whether and to what extent race/ethnicity and region may synergistically influence variety of fruit and vegetable consumption. DESIGN Cross-sectional analysis. Multivariate logistic regression predicted the likelihood of meeting fruit and vegetable variety indicators independently and in combination for each race/ethnicity and region. Interaction effects models were used to test for interaction effects between race/ethnicity and region on fruit and vegetable variety. SETTING The 2011 Behavioral Risk Factor Surveillance System (BRFSS). SUBJECTS The sample consisted of 275 864 adult respondents. RESULTS Fewer than half of respondents consumed fruit and all vegetable subcategories at least once weekly. The adjusted likelihood of meeting fruit and vegetable variety indicators varied significantly by race/ethnicity and region (P<0·05). Significant interactions between race/ethnicity and region were found for at least once weekly consumption of beans, orange vegetables, all vegetables, and fruit and all vegetables (P<0·05). CONCLUSIONS Our results reinforce previous findings that the variety of vegetable consumption is lacking and is particularly evident among some population subgroups, such as non-Hispanic blacks in the Midwest USA, who may benefit from targeted dietary interventions.

Relationship between food waste, diet quality, and environmental sustainability.

Improving diet quality while simultaneously reducing environmental impact is a critical focus globally. Metrics linking diet quality and sustainability have typically focused on a limited suite of indicators, and have not included food waste. To address this important research gap, we examine the relationship between food waste, diet quality, nutrient waste, and multiple measures of sustainability: use of cropland, irrigation water, pesticides, and fertilizers. Data on food intake, food waste, and application rates of agricultural amendments were collected from diverse US government sources. Diet quality was assessed using the Healthy Eating Index-2015. A biophysical simulation model was used to estimate the amount of cropland associated with wasted food. This analysis finds that US consumers wasted 422g of food per person daily, with 30 million acres of cropland used to produce this food every year. This accounts for 30% of daily calories available for consumption, one-quarter of daily food (by weight) available for consumption, and 7% of annual cropland acreage. Higher quality diets were associated with greater amounts of food waste and greater amounts of wasted irrigation water and pesticides, but less cropland waste. This is largely due to fruits and vegetables, which are health-promoting and require small amounts of cropland, but require substantial amounts of agricultural inputs. These results suggest that simultaneous efforts to improve diet quality and reduce food waste are necessary. Increasing consumers’ knowledge about how to prepare and store fruits and vegetables will be one of the practical solutions to reducing food waste.

Regional self-reliance for livestock feed, meat, dairy and eggs in the Northeast USA

The production of livestock feed in the USA is geographically concentrated, which poses several risks. Extreme weather events and disease outbreaks have the potential to disrupt production in these areas, which could reduce the national output of meat, dairy and eggs. Additionally, geographically concentrated livestock and feed production systems have been observed to contribute excessive nutrient loads to surrounding soil and water bodies, thereby threatening environmental sustainability. Geographic relocation of production systems has been proposed as an adaptation strategy to increase system resilience and this could take the shape of more geographically dispersed livestock feed production. We estimate the degree to which the demand for meat, dairy and eggs in the Northeast region is met with current levels of regional feed and livestock production, a term that we refer to as regional self-reliance . We combine mean annual (2001–2010) data on Northeast regional land use; crop output; meat, dairy and egg output; and food consumption with a livestock feed requirements model. An annual mean of over 6.1 million ha of land in the Northeast was dedicated to livestock feed from 2001 to 2010, with nearly 80% located in just three states (Pennsylvania, New York and West Virginia). The region is a net importer of livestock feed (in terms of total digestible nutrients and crude protein), as well as meat, dairy and eggs (in terms of total human-edible energy and protein). This is the result of a confluence of long-term regional trends that include the movement of agricultural production out of the region with a concomitant increase in the regional population and an increase in the national demand for meat, dairy and eggs. Limited slaughter output in the region is a key limiting factor to increasing the regions self-reliance for livestock products.

Greater vegetable variety and amount are associated with lower prevalence of coronary heart disease: National Health and Nutrition Examination Survey, 1999–2014

BackgroundThe 2015–2020 Dietary Guidelines for Americans (DGA) provides specific intake recommendations for vegetable variety and amount in order to protect against chronic disease. However, to the best of our knowledge, no studies have examined the link between DGA recommended vegetable variety and cardiometabolic disease. To address this research gap, our aim was to estimate the relationship between vegetable variety, vegetable amount, and prevalent cardiometabolic disease subtypes, and to assess potential determinants of vegetable variety.MethodsData on food intake and reported cardiometabolic disease status were acquired for 38,981 adults from the National Health and Nutrition Examination Survey (1999–2014). Vegetable variety was measured using a modified dietary diversity index that was adjusted for the potential confounding effects of vegetable amount. Temporal trends in vegetable variety and amount were assessed using univariate linear regression models. Multivariate logistic regression models were used to estimate the relationship between vegetable variety and prevalent disease, and between vegetable amount and prevalent disease. Multivariate ordered logistic regression models were used to assess the relationship between vegetable variety and explanatory variables.ResultsOverall, vegetable variety decreased (P = 0.035) from 1999 to 2014, but vegetable amount did not (P = 0.864). Intake of starchy vegetables decreased (P < 0.001), and intake of dark green vegetables increased (P < 0.001) over this 16-year period, but no trends were observed for other subgroups. An inverse linear relationship was observed between vegetable variety and prevalent coronary heart disease (P-trend = 0.032) but not other prevalent diseases; and between vegetable amount and coronary heart disease (P-trend = 0.026) but not other prevalent diseases. Individuals who reported consuming dark green vegetables had lower odds of having cardiovascular disease (0.86, 95% CI: 0.74–0.99) and coronary heart disease (0.78, 0.65–0.94) compared to individuals who reported not consuming any green vegetables. Living with a domestic partner was associated with greater vegetable variety (P = < 0.001), and currently smoking was associated with lower vegetable variety (P = < 0.001). Vegetable variety and amount were positively associated (P < 0.001).ConclusionsVegetable variety and amount were inversely associated with prevalent coronary heart disease. Vegetable variety was strongly associated with vegetable amount, likely mediated by reduced habituation and increased liking. Increasing vegetable variety and amount are still important messages for the public.

Characterizing trends in fruit and vegetable intake in the USA by self-report and by supply-and-disappearance data: 2001–2014

OBJECTIVE To examine the comparability of fruit and vegetable (F&V) intake data in the USA from 2001 to 2014 between data acquired from two national data collection programmes. DESIGN Cross-sectional analysis. Linear regression models estimated trends in daily per capita intake of total F&V. Pooled differences in intake of individual F&V (n 109) were examined by processing form (fresh, frozen, canned, dried and juice). SETTING What We Eat in America (WWEIA, 2001-2014) and Loss-Adjusted Food Availability data series (LAFA, 2001-2014). RESULTS No temporal trends were observed in daily per capita intake of total F&V from 2001 to 2014 using WWEIA and LAFA. Modest differences between WWEIA and LAFA were observed in mean pooled intake of most individual F&V. CONCLUSIONS WWEIA and LAFA produced similar estimates of F&V intake. However, WWEIA may be best suited for monitoring intake at the national level because it allows for the identification of individual F&V in foods with multiple ingredients, and it is structured for sub-population analysis and covariate control. LAFA does retain advantages for other research protocols, specifically by providing the only nationally representative estimates of food losses at various points in the food system, which makes it useful for examining the adequacy of the food supply at the agricultural, retail and consumer levels.