US Diet Research Articles

8648 Association of isoflavone intake and age at natural menopause

Abstract Disclosure: M. Mitsunami: None. E.R. Bertone-Johnson: None. A. Eliassen: None. J.E. Chavarro: None. Introduction: Isoflavones, a type of phytoestrogens found mainly in soy and legumes, are structurally similar to estrogens and are consumed at a relatively high rate by Asian populations with an average intake of approximately 15-40 mg/d for isoflavone. They have been reported to alleviate menopausal symptoms, such as hot flashes, suggesting that isoflavones may be biologically active in a low-estrogen environment. Previous studies have reported inconsistent associations between the intake of soy and isoflavones and age at natural menopause. Therefore, our aim was to test the hypothesis that higher isoflavone intake is related to higher age at natural menopause. Methods: We followed 85,810 premenopausal women (mean [SD], 36.5 [4.7] year) who completed a previously validated food frequency questionnaire, had not been diagnosed with cancer, and did not undergo any menopausal hormone therapy as of 1991. Diet was assessed every 4 years. Isoflavone intake was estimated from these reports. Participants self-reported their menopausal status and the type of menopause (natural, surgical, and radiation or chemotherapy) every 2 years. We used proportional hazard regression models with age in months to evaluate the relation of isoflavone intake with age at natural menopause where natural menopause was the study outcome and menopause due to surgery, radiation, or chemotherapy were censoring events. We used restricted cubic splines to assess the possibility of non-linear relations between isoflavone intake and age at menopause using the U.S. average isoflavone intake (0.8mg/d) as a reference while adjusting for potential confounders, including age at menarche, BMI, race/ethnicity, smoking status, physical activity, parity, breastfeeding, time to regular menstrual cycle, energy intake, and two dietary factors identified by principal component analysis. Results: Over 1,079,608 person-years, we observed 37,438 cases of natural menopause. Soy products contributed approximately half of isoflavone intake. There was a non-linear association between isoflavone intake and age at natural menopause (p<0.001). Women with isoflavone intakes below the U.S. national average were more likely to experience earlier onset menopause. Conversely, in women with intakes above the national average, the risk of menopause decreased with increasing isoflavone intakes, albeit plateauing at intakes of approximately 3-4mg/d (90-95th percentile of observed distribution). There was a suggestion of a positive association between isoflavone intake and earlier onset menopause for intakes above the 99th percentile of the observed distribution (∼14 mg/d). Conclusion: This study suggests a non-linear relation between isoflavone intake and age at natural menopause with a potential later onset of menopause at intake levels higher than typical in the US diet but lower than those typically observed in East Asia. Presentation: 6/2/2024

The Society of Behavioral Medicine urges passage of the PLANT (Peas, Legumes, And Nuts Today) Act.

Current US diets negatively impact human health and the environment, while shifting toward increased intake of plant-based foods could mitigate these issues. Current food policies exacerbate these problems, necessitating a reevaluation and the implementation of new policies. The Society of Behavioral Medicine urges legislators to support the PLANT Act (H.R.5023), which would enhance production, research, and development of plant-based foods and address both health and environmental concerns.

Dietary quality and dietary greenhouse gas emissions in the USA: a comparison of the planetary health diet index, healthy eating index-2015, and dietary approaches to stop hypertension

BackgroundThe Planetary Health Diet Index (PHDI) measures adherence to the dietary pattern presented by the EAT-Lancet Commission, which aligns health and sustainability targets. There is a need to understand how PHDI scores correlate with dietary greenhouse gas emissions (GHGE) and how this differs from the carbon footprints of scores on established dietary recommendations. The objectives of this study were to compare how the PHDI, Healthy Eating Index-2015 (HEI-2015) and Dietary Approaches to Stop Hypertension (DASH) relate to (a) dietary GHGE and (b) to examine the influence of PHDI food components on dietary GHGE.MethodsWe used life cycle assessment data from the Database of Food Recall Impacts on the Environment for Nutrition and Dietary Studies to calculate the mean dietary GHGE of 8,128 adult participants in the 2015–2016 and 2017–2018 cycles of the National Health and Nutrition Examination Survey (NHANES). Poisson regression was used to estimate the association of (a) quintiles of diet score and (b) standardized dietary index Z-scores with dietary GHGE for PHDI, HEI-2015, and DASH scores. In secondary analyses, we used Poisson regression to assess the influence of individual PHDI component scores on dietary GHGE.ResultsWe found that higher dietary quality on all three indices was correlated with lower dietary GHGE. The magnitude of the dietary quality-dietary GHGE relationship was larger for PHDI [-0.4, 95% CI (-0.5, -0.3) kg CO2 equivalents per one standard deviation change] and for DASH [-0.5, (-0.4, -0.6) kg CO2-equivalents] than for HEI-2015 [-0.2, (-0.2, -0.3) kg CO2-equivalents]. When examining PHDI component scores, we found that diet-related GHGE were driven largely by red and processed meat intake.ConclusionsImproved dietary quality has the potential to lower the emissions impacts of US diets. Future efforts to promote healthy, sustainable diets could apply the recommendations of the established DASH guidelines as well as the new guidance provided by the PHDI to increase their environmental benefits.

Dietary macro and micronutrients associated with MASLD: Analysis of a national US cohort database

Introduction and ObjectivesOur objective was to measure and compare the intake of macro and micronutrients in a cohort of individuals with Metabolic Syndrome Associated Steatotic Liver Disease (MASLD) compared with matched controls to identify areas of further research in this area; we identified nutrition-associated associations with MASLD in the United States general population. Materials and MethodsWe used the 2017 – 2018 NHANES dataset. Elastography Controlled Attenuation Parameter (CAP score>280) in the absence of other liver disease was defined as MASLD in adults (>18). Advanced fibrosis was defined by transient elastography >10 kPa. Controls were adults without liver disease. Results1648 MASLD cases (11.4 % advanced fibrosis) and 2527 controls were identified. MASLD cases were older (P<0.001), more likely males (P = 0.01), less likely to have a college education (P = 0.04) and more likely married (P = 0.002). MASLD cases were more likely to be of Mexican American or Hispanic ethnicity (P = 0.002), have higher BMI, and have higher prevalence of diabetes, hyperlipidemia and hypertension (P<0.001 for all). MASLD cases had higher hs-CRP (P = 0.02) and ferritin (P = 0.02). MASLD cases had lower total (P = 0.004) and added vitamin E in their diet (P = 0.002), lower vitamin K intake (P = 0.005), and higher selenium intake (P = 0.03). Caloric intake (P = 0.04), carbohydrate intake (P = 0.02), cholesterol intake (P = 0.03) and saturated fatty acid intake (P = 0.05) were higher in MASLD. Individuals with MASLD were more likely to be on a diet (P<0.001), sedentary (P = 0.008) and less likely to participate in moderate or vigorous recreational activities (P<0.001). ConclusionsThe deficiencies of micronutrients and excess of macronutrients point to oxidative stress, pro-inflammatory state, and lipotoxicity as pathways linking the US diet to MASLD. MASLD patients are more often on special diets, which may reflect prior provider counseling on diet changes to improve health.

Foraging Wild Edibles: Dietary Diversity in Expanded Food Systems.

Human food foraging in community forests offers extensive and expandable sources of food and high-quality nutrition that support chronic disease prevention and management and are underrepresented in US diets. Despite severe gaps in non-commercial "wild food" data, research in Syracuse, NY, identified substantial amounts of five key antioxidant phytochemicals in locally available, forageable foods with the potential to augment local dietary diversity and quality. Findings endorse the need for micro- and macro-nutrient research on an expanded range of forageable foods, community nutrition education on those foods, an expanded study on antioxidant phytochemical function, and the inclusion of forageables in the food system definition.

A Dietary Model of Partial Meat Replacement with Walnuts Demonstrates Changes in the Nutrient Profile and Quality of the United States Population's Diet.

The purpose of the study is to assess the impact of partial meat replacement with walnuts using a dose-escalation approach on nutrient intake and diet quality in the usual US diet. Food modeling was implemented using the nationally representative 2015-2018 National Health and Examination Survey (NHANES), with a focus on non-nut consumers, which included 2707 children and adolescents and 5190 adults. Walnuts replaced meat in a dose-escalating manner (0.5, 1, 1.5, and 2 oz walnuts per day replaced 1, 2, 3, and 4 oz meat, respectively). Diet quality was estimated using the population ratio method of the 2015 Healthy Eating Index. The usual intake of nutrients was estimated using the National Cancer Institute method. Significant differences were determined using non-overlapping 95% confidence intervals. The partial replacement of meat with walnuts demonstrated significant increases in the mean intake of fiber, magnesium, and omega-3 fatty acids and significant decreases in cholesterol and vitamin B12 in the modeled diets for children, adolescents, and adults. Additionally, the partial replacement of meat with walnuts improved overall diet quality. Walnut consumption at 1-2 oz as a replacement for some meat may improve nutrient intake and diet quality across age groups.

Impact of soda tax on beverage price, sale, purchase, and consumption in the US: a systematic review and meta-analysis of natural experiments.

As a primary source of added sugars in the US diet, sugar-sweetened beverage (SSB) consumption is presumed to contribute to obesity prevalence and poor oral health. We systematically synthesized and quantified evidence from US-based natural experiments concerning the impact of SSB taxes on beverage prices, sales, purchases, and consumption. A keyword and reference search was performed in PubMed, Web of Science, Cochrane Library, Scopus, and EconLit from the inception of an electronic bibliographic database to Oct 31, 2022. Meta-analysis was conducted to estimate the pooled effect of soda taxes on SSB consumption, prices, passthrough rate, and purchases. Twenty-six natural experiments, all adopting a difference-in-differences approach, were included. Studies assessed soda taxes in Berkeley, Oakland, and San Francisco in California, Philadelphia in Pennsylvania, Boulder in Colorado, Seattle in Washington, and Cook County in Illinois. Tax rates ranged from 1 to 2 ¢/oz. The imposition of the soda tax was associated with a 1.06 ¢/oz. (95% confidence interval [CI] = 0.90, 1.22) increase in SSB prices and a 27.3% (95% CI = 19.3, 35.4%) decrease in SSB purchases. The soda tax passthrough rate was 79.7% (95% CI = 65.8, 93.6%). A 1 ¢/oz. increase in soda tax rate was associated with increased prices of SSBs by 0.84 ¢/oz (95% CI = 0.33, 1.35). Soda taxes could be effective policy leverage to nudge people toward purchasing and consuming fewer SSBs. Future research should examine evidence-based classifications of SSBs, targeted use of revenues generated by taxes to reduce health and income disparities, and the feasibility of redesigning the soda tax to improve efficiency.

Tocopherols, Phylloquinone, Ascorbic Acid, and Sugar Contents in Hydroponically Grown Lettuce

Growing vegetables in controlled environments (CEs), such as hydroponics, aquaponics, and vertical structures, is a rapidly expanding industry in Florida and the United States, especially in nearby urban areas. Although lettuce (Lactuca sativa) is still mostly produced in fields, growing in CEs proximal to urban areas has become increasingly popular because it may facilitate reduced transportation time and associated postharvest degradation. Lettuce is among the top-most consumed vegetables in the United States and could provide some of the nutrition missing in the US diet. This research was planned to understand the levels of some vitamins that are key for human health, including vitamin E (tocopherols), vitamin K1 (phylloquinone), and vitamin C (ascorbic acid), in lettuce grown in greenhouse hydroponics. Lettuce germplasm was grown using the hydroponic nutrient film technique system in three greenhouse experiments: at the beginning, middle, and end of the Florida, USA, growing season (from Aug 2020 to Mar 2021). Genetic variation for these vitamins were found among the germplasm tested in the four morphological types of lettuce, romaine, Boston, Latin, and leaf. In addition, a sugar analysis was conducted in this germplasm, of which fructose was the most abundant sugar. A significant genotype × environment (G × E) interaction was observed, indicating that the levels of these compounds, especially vitamins, was environment dependent. However, the presence of certain non-crossover G × E interactions indicates that selecting lettuce in a representative environment could result in new cultivars with higher vitamin content. This research marks the initial steps to improve lettuce for these vitamins, which can contribute to better health of US consumers, not for the highest amount of these compounds in lettuce but for the offset due to its high consumption.

Application of a New Carbohydrate Food Quality Scoring System: An Expert Panel Report

Carbohydrate foods (≥40% energy from carbohydrates) are the main source of energy in the US diet. In contrast to national-level dietary guidance, many regularly consumed carbohydrate foods are low in fiber and whole grains but high in added sugar, sodium, and/or saturated fat. Given the important contribution of higher-quality carbohydrate foods to affordable healthy diets, new metrics are needed to convey the concept of carbohydrate quality to policymakers, food industry stakeholders, health professionals, and consumers. The recently developed Carbohydrate Food Quality Scoring System is well aligned with multiple key healthy messages on nutrients of public health concern from the 2020-2025 Dietary Guidelines for Americans. Two models are described in a previously published paper: one for all non-grain carbohydrate-rich foods (e.g., fruits, vegetables, legumes) known as the Carbohydrate Food Quality Score-4 (CFQS-4), and one for grain foods only known as the Carbohydrate Food Quality Score-5 (CFQS-5). These CFQS models provide a new tool that can guide policy, programs, and people towards improved carbohydrate food choices. Specifically, the CFQS models represent a way to unify and reconcile diverse ways to describe different types of carbohydrate-rich foods (e.g., refined vs. whole, starchy vs. non-starchy, dark green vs. red/orange) and make for more useful and informative messaging that better aligns with a food's nutritional and/or health contributions. The present paper's aims are to show that the CFQS models can inform future dietary guidelines and help support carbohydrate food recommendations with other health messages aimed at promoting foods that are nutrient-dense, fiber-rich, and low in added sugar.

Using cereal to increase dietary fiber intake to the recommended level and the effect of fiber on bowel function in healthy persons consuming North American diets

Background:Dietary fiber intake remains low despite increasing evidence for its health benefits, including laxation. Objective:We aimed to assess the effects of increasing fiber intake on bowel habits and gastrointestinal tolerance in healthy persons consuming a typical Canadian or US diet. Design:Under a randomized crossover design, 23 free-living participants consumed a typical Canadian or US diet (35% fat, 12 g fiber/d) and received 25.0–28.7 g fiber/d from each of 5 breakfast cereals: All-Bran (AB), Bran Buds with Corn (BBC), Bran Buds with Psyllium (BBP), BBC with viscous fiber blend (VFB), or a low-fiber control for 3 wk, with each study arm separated by a washout of ≥1 wk. Seven-day stool collections and a symptom diary were obtained during the last week of each study arm. Results:All study cereals induced significant (P < 0.05) increases in fecal bulk from the control diet at 128 ± 38 g to 199 ± 56, 199 ± 57, 247 ± 87, and 197 ± 63 g with consumption of AB, BBC, BBP, and VFB, respectively; less intestinal transit time; and significantly (P < 0.05) greater bowel movement frequency. Despite the increased activity of the bowel, a positive level of comfort was maintained. BBP was more effective than other cereals in terms of increasing fecal wet weight (P < 0.05). Conclusion:Water-insoluble dietary fibers (ie, AB and BBC) and their mixtures with water-soluble fibers (ie, BBP and VFB) in the form of breakfast cereals (2.5 servings/d) proved to be a practical way of increasing fiber intake to recommended levels, while maintaining a good level of tolerance.

Biochemical and behavioral effects of decreasing dietary linoleic acid and increasing eicosapentaenoic acid and docosahexaenoic acid in a rat chronic monoarthrits model

Clinical studies have demonstrated that decreasing linoleic acid (LA) while increasing eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in diets evokes an analgesic effect in headache sufferers. We utilized a rat chronic monoarthritis model to determine if these analgesic effects can be reproduced in rats and to and further probe potential analgesic mechanisms. We fed 8 rats a control diet (with fatty acid levels similar to standard US diets) and 8 rats a low LA diet with added EPA and DHA (H3L6 diet) and after 10 weeks, performed a unilateral intraarticular injection of Complete's Freund Adjuvant (CFA). We evaluated thermal and mechanical sensitivity as well as hind paw weight bearing prior to and at 4 and 20 days post CFA injection. At 28 days post CFA injection rats were euthanized and tissue collected. H3L6 diet fed rats had higher concentrations of EPA and DHA, as well as higher concentrations of oxidized lipids derived from these fatty acids, in hind paw and plasma, compared to control fed rats. LA and oxidized LA metabolites were lower in the plasma and hind paw of H3L6 compared to control fed rats. Diet did not affect thermal or mechanical sensitivity, nor did it affect hind paw weight bearing. In conclusion, the H3L6 diet evoked biochemical changes in rats but did not impact pain related behavioral measures in this chronic monoarthritis model.

Effect of increasing plant protein intake on protein quality and nutrient intake of US adults.

Three cycles of NHANES (2013-2018) were used to assess protein intake, protein quality (PDCAAS), protein cost, and nutrient intakes across quartiles of plant protein intake (Q1: <28.2%; Q2: 28.2%-<32.1%; Q3: 32.1-<36.2%; Q4: ≥36.2%) over a 24 hr period (≥ 19 years, n=14,888). Grains represented the primary source of plant protein across quartiles and increased from 5.01% (Q1) to 13.5% (Q4). Across all the USDA's Food and Nutrient Database for Dietary Studies (FNDDS) food groups, grains were the most economical source of protein (24.3-26 g protein/$1). Legumes were the most economical plant-based protein (28-37.7 g protein/$1) within the "Protein Foods" FNDDS group. Absolute protein intake (96.6 g/day) and PDCAAS (0.91) of diets were progressively lower from Q1 to 72.0 g/day and 0.8 in Q4, respectively. Modelling the replacement of 50% of amino acids from grains in the diet with amino acids from legumes increased the PDCAAS by 10% in Q4. Intake levels of fibre, folate, iron, and zinc, were higher in Q2-4 compared to Q1, but had lower intakes of vitamin B12 and vitamin D. Amino acid complementation is required to effectively integrate higher levels plant protein into US diets.

Amino Acid Nitrogen Isotope Ratios Respond to Fish and Meat Intake in a 12-Week Inpatient Feeding Study of Men

BackgroundThe natural abundance nitrogen stable isotope ratio (NIR) of whole tissue correlates with animal protein intakes, including meat and fish. Amino acid (AA) NIRs (NIRAAs) are more variable than the whole-tissue NIRs and may thus better differentiate among foods. ObjectivesWe evaluated whether NIRAAs were associated with intakes of fish and meat and whether these dietary associations were larger than with whole-tissue NIRs. MethodsMen were recruited at the National Institute of Diabetes and Digestive and Kidney Diseases in Phoenix, Arizona, and randomly assigned to one of eight 12-wk inpatient dietary interventions, which varied the presence/absence of fish, meat, and sugar-sweetened beverages (SSBs) in all possible combinations. Fasting blood was drawn pre- and postintervention and plasma and RBC NIRAAs (free and protein-bound) were measured as secondary outcomes in 32 participants. Multivariable regression was used to determine responses of postintervention NIRAAs to dietary variables, and logistic regression was used to calculate receiver operating characteristic AUCs. ResultsMost plasma NIRAAs increased with fish and meat intakes, but to a greater extent with fish intake. The largest increase in response to fish intake was plasma NIRLeucine (β = 2.19, SE = 0.26). The NIRThreonine decreased with both fish and meat intakes. Fewer RBC NIRAAs increased with fish intake, and only RBC NIRProline increased with meat intake. No plasma or RBC NIRAA responded to SSB intake. We identified fish intake with a high degree of accuracy using plasma NIRLeucine (corrected AUC, cAUC = 0.96) and NIRGlutamic acid/glutamine (cAUC = 0.93), and meat intake to a lower degree using plasma NIRProline (cAUC = 0.80) and RBC NIRProline (cAUC = 0.85). ConclusionsPlasma and RBC NIRAAs were associated with fish and meat intakes but were not superior to whole-tissue stable isotope biomarkers in identifying these intakes in a US diet. This trial is registered at www.clinicaltrials.gov as NCT01237093.

Potential for Front of Pack Labeling Exposure to Impact US Dietary Choices: A Population-Based Cross-Sectional Study Using NHANES 2017-2018.

In recent years, front-of-pack nutrition labeling (FOPL) schemes have proliferated, but the components of the diet subject to FOPL have not been described. This study quantified the proportion and elements of the diet that would be subject to FOPL in the US. The 2017–2018 National Health and Nutrition Examination Survey (n = 7121; age ≥2 year) 24-h dietary recalls were used to identify foods/beverages subject to FOPL. The proportion of dietary energy and additional dietary constituents subject to FOPL was estimated. Overall, 57% of dietary energy would be subject to FOPL. Individuals consuming more away-from-home meals had lower exposure to FOPL. Adults with a healthy-weight and those consuming a more healthful diet had more exposure to FOPL. Protein, sodium, potassium, whole fruit, vegetables, and unprocessed meats were less subject to FOPL as compared to total sugars, added sugars, calcium, fruit juice, milk, yogurt, nuts/seeds and whole grains. Because less than 60% of the diet would be impacted by FOPL, implementation of such a policy may have limited reach for the US diet and demonstrates some inconsistencies with current dietary guidance regarding the under- and over-representation of key food groups and nutrients.

The impact of excessive protein consumption on human wastewater nitrogen loading of US waters

Total and per capita protein consumption rates in US diets, whether from plant or animal sources, rank among the highest in the world. When protein consumption outpaces physiologic protein demands, excess amino acids are degraded in the human body and nitrogen (N) is excreted and released to the environment, mainly in the form of urea. Such excess reactive N can enter downstream environments, thereby impairing human and ecosystem health as well as contributing to economic losses. We show that matching protein consumption with physiologic requirements would reduce US hydrologic N losses to aquatic ecosystems by 12% and overall (atmospheric and hydrologic) N losses to ecosystems by 4%. Were US citizens to consume protein at recommended rates, projected N excretion rates in 2055 would be 27% less than they are today, despite population growth. Optimizing US protein consumption to levels that meet human health standards has environmental benefits on par with improving wastewater treatment using existing technology, while also generating impactful economic benefits.

Ultra-Processed Foods Have a Lower Glycemic Index and Load Compared to Minimally Processed Foods

ObjectivesUltra-processed foods (UPFs) make up the majority of calories in the US diet. Glycemic index (GI) and load (GL) are measures of the quality and quantity of carbohydrates in food based on their effect on blood glucose post consumption. Diets high in UPFs and GI/GL are both associated with numerous chronic metabolic diseases. Therefore, this study sought to examine the GI and GL of foods assigned to different food processing groups. It was hypothesized that GI and GL would be lowest in minimally processed foods (MPF) compared to processed (PRF) and UPF (with no difference between PRF and UPF) for all food items and food groups.MethodsGI and GL values produced by healthy/normal individuals for 2,205 food items were collected from published sources. Food items were then coded by processing levels determined by the NOVA Classification. In addition, food items were coded into eight groups (i.e., Beverages; Beans, Nuts, & Seeds [BNS]; Dairy; Fats & Sweets; Fruits & Fruit Juices; Grains; Meat Poultry & Fish; and Vegetables). Hierarchical linear modeling was used to determine significance with an alpha of 0.05.ResultsThe effect of food processing on GI (p < 0.001) and GL (p < 0.001) was contrary to the hypothesis as the mean GI and GL were highest for MPF: GI (MPF: 56 ± 20, PRF: 53 ± 19, UPF: 50 ± 18), GL: (MPF: 18 ± 11, PRF: 16 ± 13, UPF; 12 ± 8). Among food groups, there was no interaction between food processing and GI (p = 0.084), but an interaction for GL was found (p < 0.001). Moreover, the direction of difference in GL was inconsistent among food groups: BNS (MPF: 6 ± 4, PRF: 9 ± 5, UPF: 10 ± 5), Dairy (MPF: 5 ± 5, PRF: 3 ± 0, UPF: 8 ± 6), and Grains (MPF: 23 ± 9, PRF: 21 ± 15, UPF: 13 ± 9).ConclusionsAcross all analyzed food items, UPF had a lower GI and GL compared to MPF and PRF (GL only), with mixed findings among food groups. Surprisingly, ultra-processing of grains suggests improvement of glycemic responses, perhaps by the addition of protein, fat, and sugars. These results suggest that the negative health outcomes associated with consumption of UPF may be due to other unhealthful aspects (e.g., energy density, food additives, and increased palatability), not higher GI and GL.Funding SourcesAJB has received the 2021–2022 Graduate Completion Fellowship from the School of Life Sciences, Arizona State University.

Diet-Induced Mouse Model of Nonalcoholic Steatohepatitis That Replicates the Human Disease

ObjectivesDeveloping a mouse model of nonalcoholic steatohepatitis (NASH) with obesity and fibrosis. MethodsWe fed agouti yellow male mice, which are hyperphagic, a western diet and water containing high fructose corn syrup for either 16 weeks or a year. We measured body weight and composition; we evaluated the development of NASH by histopathology and analyzed changes in gene expression by RNASeq. ResultsAfter 16 weeks, the mice had higher body weight and fat mass. The mice developed NASH with activity scores 5-6; this was confirmed by higher liver triacylglycerol content, elevated plasma ALT and AST activities, and greater hepatic infiltration by CD45-expressing leukocytes. The mice developed liver fibrosis, which was stage 1 after 16 weeks, and stage 3 after a year. Liver gene expression analysis showed increases in lipogenesis-, inflammation-, and fibrosis-related genes. Gene set enrichment analysis showed that 90% of the pathways were similarly upregulated or downregulated in the livers of mice and in human patients with NASH. ConclusionsIn this mouse model, NASH is induced with a diet similar to the average US diet, without nutritional deficiencies or hepatotoxins. NASH replicates the human disease, including the development of advanced fibrosis and very similar changes in gene expression. These similarities make this model useful for the study the pathophysiology of NASH and for preclinical studies of new drugs. Funding SourcesNIH, NSFC.

Self-Selected Diets in the US Show a Reduction in Carbon Footprints Over Ten Years

ObjectivesGrowing evidence indicates the need for demand-side changes to global food systems to meet nutritional needs while staying within planetary boundaries. Previous research documented the greenhouse gas emissions (GHGE, or carbon footprint) of self-selected diets in the US from the 2005–2010 National Health and Nutrition Examination Survey (NHANES), but more recent such data do not exist. To address this gap, we assessed the carbon footprint of diets reported in the 2015–2016 NHANES, and analyzed the 10-year trend from the 2005–2006 wave. MethodsFoods eaten by adults (N = 5,060), ages 18 years and older, reported in a one-day 24-hour recall in NHANES 2005–2006 were translated to commodity intakes using recipes from the US Environmental Protection Agency’s Food Commodity Intake Database (FCID). GHGE (kg carbon dioxide equivalents, or CO2-eq, per kg of edible portion) in the production of these commodities were calculated from the database of Food Impacts on the Environment for Linking to Diets (dataFIELD), then summed for each person to get a total one-day dietary carbon footprint. Newly reported foods consumed by adults (N = 4,982) in 2015–2016 required new recipes to be translated to commodity intakes. We developed these recipes by modifying similar existing FCID recipes. If no similar food existed, recipes were constructed using ingredients and proportions from the US Department of Agriculture’s FoodData Central. ResultsMean food-related GHGE decreased 7.9% across the ten-year period, from 4.9 to 4.5 kg CO2-eq/day. Controlling for energy intake, age, gender, race, and income-to-poverty ratio, one-day food-related GHGE were still lower in 2015–2016 than they were in 2005–2006, by 0.3 kg CO2-eq (p < 0.02). ConclusionsThe average carbon footprint of US adults’ self-selected diets has decreased over time. This is a positive development for efforts to slow climate change. However, evidence reported elsewhere shows that US diets do not meet current nutritional recommendations. Additional research is needed to find and encourage “win-win” diets that meet nutritional objectives, while reducing environmental impacts. Funding SourcesWellcome Trust, National Cancer Institute, Health Resources and Services Administration.

Declining greenhouse gas emissions in the US diet (2003–2018): Drivers and demographic trends

The food system is a major driver of climate change, and many have noted that a shift in consumption patterns is necessary to achieve greenhouse gas (GHG) emission reduction targets that can limit global mean temperature rise ≤2 °C. Beef is the largest GHG emitting commodity in the United States, and in recent years national consumption has been declining. Little is understood about how this change in consumption and other dietary trends have influenced the overall GHGs associated with the US diet. The objective of this study is to estimate the GHGs of changing dietary patterns from individual self-selected diets in the United States from 2003 to 2018 and evaluate trends and potential disparities among demographic subgroups. Life cycle emissions factors (representing food production impacts) for food commodities from dataFIELD were used to estimate GHGs associated with food items described by US adults (>20 years, n = 39,750) in the National Health and Nutrition Examination Survey (NHANES). From 2003 to 2018, the mean GHG emissions associated with the US diet fell by more than 35%, from 4.02 kg CO2e per day per capita, to 2.45 kg CO2e per day per capita, despite average caloric intake remaining relatively stable over the same period. Average beef consumption declined 40% per capita over the study period, which contributed to more than 50% of the observed GHG savings in the diet over the study period. All demographic variables included in this analysis (age, gender, race/ethnicity, and ratio of family income to the federal poverty level) exhibited a reduction in GHG emissions associated with their diets. However, GHGs and overall rate of change differed across demographic subgroups. Black women had the lowest GHG emissions associated with their diet, 1.92 kg CO2e per capita per day. Men aged 20–34 had the largest rate of reduction in GHGs associated with diet changes, with an average annual decline of 210g CO2e per day per capita over the study period. Despite GHGs associated with the US diet falling over the last 15 years, the US diet is still exceeding established GHG limits to meet global targets, such as the Paris Agreement. Additional research is needed to better understand motivations and drivers that have reduced emissions in the diet over this period, particularly in demographic subgroups that showed both low impact and a rapid decline in emissions.

How Americans eat red and processed meat: an analysis of the contribution of thirteen different food groups.

Dietary patterns characterised by high intake of red and processed meat are associated with detrimental health and environmental outcomes. To better understand how Americans consume red and processed meat, this study examined the food groups that are the greatest contributors to red and processed meat intake in US diets. Cross-sectional analysis of total red and processed meat, unprocessed red meat and processed meat using data from the National Health and Nutrition Examination Survey (2015-2016 and 2017-2018). Items containing red or processed meat were classified into thirteen mutually exclusive food groups. For highly consumed food groups (≥10 % of meat intake), contribution to meat intake was further assessed by source, sex, income and education. Nationally representative sample of the US population. Teens (aged 12-19 years) and adults (aged ≥20 years) who reported meat consumption (n 8178). Meat mixed dishes (18·6 % (95 % CI 16·2, 20·9)), burgers (17·3 % (95 % CI 15·3, 19·3)) and beef excluding ground (17·0 % (95 % CI 13·8, 20·1)) were the top contributors to unprocessed red meat intake. For processed meat, four food groups made up about four-fifths of total intake: cold cuts and cured meats (37·7 % (95 % CI 34·6, 40·8)), sausages and frankfurters (20·3 % (95 % CI 18·6, 22·0)), bacon (14·0 % (95 % CI 12·3, 15·6)) and pizza (10·1 % (95 % CI 8·7, 11·5)). Fast-food restaurants were the top source for burgers and pizza, whereas stores were the top source for all other highly consumed food groups. Few differences were seen in patterns of intake by sociodemographic characteristics. No single food group accounts for a majority of meat intake in the USA. Many behaviour change opportunities for healthier, more sustainable substitutions exist.