American Journal of Clinical Nutrition最新文献

Background: Suboptimal diets may promote undesired weight gain in youths, with high ultraprocessed food (UPF) intake becoming a significant concern in the United States.

Objectives: We evaluated the association between UPF intake and body mass index [BMI (in kg/m²)] change in large United States youth cohorts.

Methods: Participants included children and adolescents (7-17 y) from the Growing Up Today Study (GUTS1 and GUTS2) who completed baseline and ≥1 follow-up diet and anthropometrics assessment (GUTS1 1996-2001: N = 15,797; GUTS2 2004-2011: N = 9720). Follow-up years were based on diet assessment availability. UPFs were categorized using the Nova system, with intakes evaluated as the cumulative mean percent energy from UPFs and subgroups. BMI was assessed using self-reported body weight/height. Changes in BMI annually and over 2, 4-5, and 7 y in association with UPF intake were examined using multivariable repeated-measure linear mixed models.

Results: At baseline, the mean percentage of energy from UPFs was 49.9% in GUTS1 and 49.5% in GUTS2 participants; mean BMI was 18.7 and 19.8, respectively. After multivariable adjustments for sociodemographic and lifestyle factors, each 10% increment in UPF intake was associated with a 0.01 (95% confidence interval: 0.003, 0.03) increase annually and a 0.07 (0.01, 0.13) increase over 5 y in GUTS1 participants. In GUTS2, increases were 0.02 (0.003, 0.04) annually and 0.09 (0.01, 0.18) over 4 y. Among GUTS1, statistically significant annual BMI increases of 0.02-0.07 were associated with elevated intake of ultraprocessed breakfast cereals, savory snacks, and ready-to-eat/heat foods, especially pizza, burgers, and sandwiches. No association was found between UPF intake and overweight/obesity risk.

Conclusions: A higher UPF intake was associated with a modest yet significant increase in BMI in large prospective cohorts of United States youths, calling for public health efforts to promote healthful food intake among youths to prevent excessive weight gain.

Recent litigation has led to a situation where preterm cow milk-based infant nutritional products (PCMBPs) may soon have limited or no availability in the United States. Given their limited availability, similar products based only on human milk are unlikely to meet the needs of most preterm infants requiring such products, especially those born >1500 g or very preterm infants born at <1500 g after they reach 34-35 wk postmenstrual age. Alternative nutritional strategies, used before the introduction of specialized preterm products, would require modular nutrient additions to a formula designed for full-term infants and donor or maternal milk. The addition of modular products would require careful calibration to provide needed macro and micronutrients which would expose infants to risks of contamination, poor growth, and limited bioavailability of some of these modulars. Substantial risks of metabolic derangements, and ultimately, poor outcomes would occur. In the long-term greater availability and support for the use of human milk-based products is needed. However, policymakers cannot assume that PCMBPs will not be critically needed and should identify strategies for their continued marketplace availability.

Universal growth standards for under-five children, given the worldwide variation in healthy growth and several determinants of anthropometry, are imprecise measures of nutritional status, particularly when used cross-sectionally. In constructing the global-use WHO growth standard, linear growth differences between contributing sites and pooled mean were >0.2 SD in 37% of observations. Systematic reviews confirm even greater variability, notably amplified for weight-for-age and head-circumference-for-age metrics. Unsurprisingly, developed nations had higher, and LMICs lower, growth dimensions. Contextual growth references predict neonatal morbidities, pathological short stature, macrocephaly, cardiometabolic risk factors, and adult noncommunicable diseases better than the WHO standards. Child body composition also varies contextually, with greater adiposity despite comparable weights in South Asian populations. Thus, contextual references, though not the perfect solution, are better suited for everyday practice and nutrition policy. Growth standards should only be used as a screening for clinical judgments aided by precise biomarkers.

Background: Human milk (HM) composition data are widely used in clinical, regulatory, and public health initiatives. The existing HM profiles in U.S. and Canadian nutrient databanks are outdated and now considered inappropriate to estimate current nutrient intakes. Recent reviews have underscored the limited North American data available to generate a new profile.

Objective: To describe concentrations and sources of variability of nutrients in HM from a large cohort collected in Canada.

Methods: The Maternal-Infant Research on Environmental Chemicals (MIREC) study recruited participants in the first trimester of pregnancy from 10 Canadian cities between 2008-2011. HM samples (n=559-835, depending on nutrient) were collected 3-10 weeks post-partum and analyzed for minerals (calcium, magnesium, phosphorus, potassium, sodium, manganese, molybdenum, zinc, copper, iodine, selenium), vitamin D (vitamin D₃, 25-(OH)D₃), folate vitamers (folic acid, 5-methyltetrahydrofolate, total folates), and fatty acids (panel). We examined associations between participant characteristics and log-transformed nutrient concentrations using linear regression.

Results: Concentrations of HM components in MIREC samples were within the range observed in literature except for manganese, which was >100 fold lower than the value in the existing Canadian nutrient databank profile (2.43 [SD 2.84] compared to 260 ng/g). In multivariable models, concentrations of folate vitamers, vitamin D and fatty acids demonstrated greater variability with maternal and sample characteristics than minerals. Factors such as relevant supplement use, body mass index (BMI), and for vitamin D, skin color and season, had a larger impact on nutrient concentrations than characteristics typically standardized in HM research, such as maternal or infant health, and method of collection.

Conclusion: HM mineral concentrations from this study meet the methodological inclusion criteria for updating nutrient databank values and dietary reference intakes. Consideration of factors such as diet, skin colour, and BMI will be important for selecting studies for developing representative reference values based on human milk.

Background: Serum low density lipoprotein (LDL) cholesterol shows marked interindividual variation in response to the replacement of saturated fatty acids (SFAs) with unsaturated fatty acids (UFAs).

Objectives: To demonstrate the efficacy of United Kingdom guidelines for exchanging dietary SFAs for UFAs, to reduce serum LDL cholesterol and other cardiovascular disease (CVD) risk factors, and to identify determinants of the variability in LDL cholesterol response.

Methods: Healthy males (n = 109, mean ± SD age 48 ± 11 y; BMI 25.1 ± 3.3 kg/m²), consumed a higher-SFA/lower-UFA diet for 4 wk, followed by an isoenergetic, lower-SFA/higher-UFA diet for 4 wk (achieved intakes SFA:UFA as % total energy 19.1:14.8 and 8.9:24.5, respectively). Serum LDL cholesterol, CVD risk markers, peripheral blood mononuclear cell (PBMC) gene expression, and dietary intakes were assessed at baseline and the end of each diet.

Results: Transition from a higher-SFA/lower-UFA to a lower-SFA/higher-UFA diet significantly reduced fasting blood lipids: LDL cholesterol (-0.50 mmol/L; 95% confidence interval [CI]: -0.58, -0.42), high-density lipoprotein (HDL) cholesterol (-0.11 mmol/L; 95% CI: -0.14, -0.08), and total cholesterol (TC) (-0.65 mmol/L; 95% CI:-0.75, -0.55). The dietary exchange also reduced apolipoprotein (apo)B, TC:HDL cholesterol ratio, non-HDL cholesterol, E-selectin (P < 0.0001), and LDL subfraction composition (cholesterol [LDL-I and LDL-II], apoB100 [LDL-I and LDL-II], and TAG [LDL-II]) (P < 0.01). There was also an increase in plasma biomarkers of cholesterol intestinal absorption (β-sitosterol, campesterol, cholestanol), and synthesis (desmosterol) (P < 0.0001) and fold change in PBMC LDL-receptor mRNA expression relative to the higher-SFA/lower-UFA diet (P = 0.035). Marked interindividual variation in the change in serum LDL cholesterol response (-1.39 to +0.77 mmol/L) to this dietary exchange was observed, with 33.7% of this variation explained by serum LDL cholesterol before the lower-SFA/higher-UFA diet and reduction in dietary SFA intake (adjusted R² 27% and 6.7%, respectively). APOE genotype was unrelated to serum LDL cholesterol response to SFA.

Conclusions: These findings support the efficacy of United Kingdom SFA dietary guidelines for the overall lowering of serum LDL cholesterol but showed marked variation in LDL cholesterol response. Further identification of the determinants of this variation will facilitate targeting and increasing the efficacy of these guidelines. The RISSCI-1 study was registered with ClinicalTrials.Gov (No. NCT03270527).

Background: Consumers are increasingly interested in environmentally sustainable dietary patterns. However, specific signals (e.g., language, labels, logos, or packaging) American consumers use to identify environmentally sustainable products are yet to be explored.

Objectives: To determine perception and preferences for environmentally sustainable food and associated health and demographic factors associated with consumers' use of signals for environmentally sustainable food products in a nationally representative survey of United States consumers.

Methods: Repeated cross-sectional data were collected for the 2019 and 2020 annual online Food and Health Survey by the International Food Information Council. Three questions were analyzed: 1) the stated importance of environmentally sustainable food products, 2) signals consumers use to identify environmentally sustainable food/beverage products, and 3) the impact of environmental sustainability on food/beverage purchase decisions. Questions 2 and 3 were asked only from participants who stated environmental sustainability is important in question 1. Options provided for signals for environmentally sustainable products were recyclable packaging, minimal packaging, labeled organic, labeled locally grown, labeled sustainably sourced, and labeled non-genetically modified organisms (GMOs)/not bioengineered. Poisson regression and logistic regressions were performed to assess associations.

Results: Of 1905 completers, 1059 (55.6%) answered that it was somewhat or very important that food products purchased/consumed were environmentally sustainable. Of those, 94% used ≥1 of the 6 signals to determine environmental sustainability when shopping. Some signals were selected despite little association with environmental sustainability (e.g., locally grown and non-GMO/not bioengineered). The number of signals consumers used was associated with education, race/ethnicity, health status, and the level of impact they reported that sustainability plays in their decisions. Associations between consumer characteristics and the use of different signals for environmental sustainability were heterogeneous.

Conclusions: Even among consumers who value environmental sustainability in food products, specific signals used by different respondents varied across demographics and health characteristics.

Background: Avocado intake improves dietary fat quality, but the subsequent impact on red blood cell (RBC) saturated (SFA), monounsaturated (MUFA), polyunsaturated (PUFA), and trans-fatty acid (TFA) composition and association with cardiometabolic health, has not been elucidated.

Objectives: To compare the effect of consuming 1 avocado/d relative to habitual diet (HAB) on RBC-FA profiles, and their association with visceral adiposity and cardiometabolic risk factors (CMRFs) in individuals with abdominal obesity.

Methods: RBC-FA profiling at baseline, 3- and 6 mo was conducted in participants (n = 994) from the Habitual Diet and Avocado Trial (HAT). HAT was a multisite, free-living, parallel-arm intervention study in which participants were randomly assigned to either the avocado-supplemented group (AVO, usual diet with 1 avocado/d) or the HAB group (usual diet with limited avocado intake) for 6 mo. Changes in RBC-FA profiles, a secondary outcome measure, were determined within and between groups using linear regression and mixed effect models, adjusting for age, sex, BMI, clinical site, smoking status, and percentage of energy intake from fat at baseline. The association between changes in RBC-FAs with visceral adiposity measures and CMRFs was assessed after covariate and False Discovery Rate (FDR <0.05) adjustment.

Results: No major differences in RBC-FA profiles were observed between groups, with the exception of MUFA cis-vaccenic [18:1n-7c], which was significantly higher in AVO (β: 0.11 [0.05, 0.17]) compared with the HAB (β: 0.03 [-0.03, 0.08]) participants. In the HAB but not AVO group, increases in MUFA cis (18:1n-7c, oleic [18;1n-9c], erucic [22:1n-9c]) and MUFA trans (palmitelaidic [16:1n-7t], vaccenic [18:1n-7t], elaidic [18:1n-9t], and petroselaidic [18;1n-10-12t), as well as PUFA γ-linolenic [18:3n-6], dihomo-γ-linolenic [20:3n-6], arachidonic [20:4n-6], and α-linolenic [18:3n-3] were associated with unfavorable changes in visceral adiposity measures, lipid profiles, glucose, insulin and high sensitivity C-reactive protein concentrations.

Conclusions: Daily avocado intake over 6-mo modified RBC-MUFA composition, notably 18:1n-7c, and potentially mitigated some of the unfavorable individual RBC-FA-CMRF associations observed over time in the HAB group. This trial was registered at https://clinicaltrials.gov/study as NCT03528031.

Background: Weight loss through lifestyle interventions, notably low-energy diets, offers glycemic benefits in populations with overweight-associated prediabetes. However, >50% of these individuals fail to achieve normoglycemia after weight loss. Circulating lipids hold potential for evaluating dietary impacts and predicting diabetes risk.

Objectives: This study sought to identify serum lipids that could serve as evaluative or predictive biomarkers for individual glycemic changes following diet-induced weight loss.

Methods: We studied 104 participants with overweight-associated prediabetes, who lost ≥8% weight via a low-energy diet over 8 wk. High-coverage lipidomics was conducted in serum samples before and after the dietary intervention. The lipidomic recalibration was assessed using differential lipid abundance comparisons and partial least squares discriminant analyses. Associations between lipid changes and clinical characteristics were determined by Spearman correlation and Bootstrap Forest of ensemble machine learning model. Baseline lipids, predictive of glycemic parameters changes postweight loss, were assessed using Bootstrap Forest analyses.

Results: We quantified 439 serum lipid species and 9 related organic acids. Dietary intervention significantly reduced diacylglycerols, ceramides, lysophospholipids, and ether-linked phosphatidylethanolamine. In contrast, acylcarnitines, short-chain fatty acids, organic acids, and ether-linked phosphatidylcholine increased significantly. Changes in certain lipid species (e.g., saturated and monounsaturated fatty acid-containing glycerolipids, sphingadienine-based very long-chain sphingolipids, and organic acids) were closely associated with clinical glycemic parameters. Six baseline bioactive sphingolipids primarily predicted changes in fasting plasma glucose. In addition, a number of baseline lipid species, mainly diacylglycerols and triglycerides, were predictive of clinical changes in hemoglobin A1c, insulin and homeostasis model assessment of insulin resistance.

Conclusions: Newly discovered serum lipidomic alterations and the associated changes in lipid-clinical variables suggest broad metabolic reprogramming related to diet-mediated glycemic control. Novel lipid predictors of glycemic outcomes could facilitate early stratification of individuals with prediabetes who are metabolically less responsive to weight loss, enabling more tailored intervention strategies beyond 1-size-fits-all lifestyle modification advice. The PREVIEW lifestyle intervention study was registered at clinicaltrials.gov as NCT01777893 (https://clinicaltrials.gov/study/NCT01777893).