American Journal of Clinical Nutrition最新文献

Background: Health-related quality of life (HRQoL) is a central aspect of overall health and a crucial factor in dietary interventions, as it may determine both dietary compliance and sustained adherence.

Objective: We assessed the effect on HRQoL between: 1) the Low-Carbohydrate High-Fat (LCHF) diet and 2) the High-Carbohydrate Low-Fat (HCLF) diet and evaluated the impact on dietary compliance and sustained adherence.

Methods: This is a prespecified secondary analysis from a randomized controlled trial in people with type 2 diabetes. Participants were randomized 2:1 to follow either LCHF or HCLF for six months with a post-intervention visit nine months after inclusion. Liver biopsies were performed at baseline and after six months, the Diabetes-39 HRQoL questionnaire, standard clinical and compliance assessments were conducted at baseline, three months, six months and nine months (post-intervention), sustained adherence was assessed at the post-intervention visit.

Results: We randomized 165 participants, 96 (58%) were female. At baseline, the median age was 56 (IQR, 50-63) years, mean BMI was 33+7 kg/m², total median HRQoL score was 88 (IQR, 70-111), mean hemoglobin A1c (HbA1c) was 56+10 mmol/mol and 141 (88%) had metabolic dysfunction-associated steatotic liver disease (MASLD). After six months intervention, HRQoL improved in both groups (LCHF: -14.5; (95% CI: -20.7,-8.36); p<0.001; HCLF; -13.7; (95%CI: -22.7,-4.6); p=0.003) with no mean difference in change between groups (Δ) p=0.855. Higher improvements in HRQoL were associated with a higher compliance with the diets (Spearman's rho; -0.183; p=0.0378) and increased the likelihood of sustained adherence to the LCHF diet.

Conclusion: HRQoL improved in both dietary intervention groups with no difference between groups. Dietary compliance was associated with improved HRQoL and may play a role in sustained adherence to the LCHF diet.

Clinical trial registry number: ClinicalTrials.gov (NCT03068078), https://clinicaltrials.gov/study/NCT03068078.

Background: Accurate methods for estimating resting energy expenditure (REE) are important to ensure adequate nutritional treatment in colorectal cancer (CRC) survivors.

Objectives: This study aims to determine the agreement between REE estimated by commonly used predictive equations and by whole-room indirect calorimetry (WRIC).

Methods: This cross-sectional study included 31 CRC survivors {age: 53-78 y; mean [standard deviation (SD)]; body mass index 28.7 [4.28] kg/m²}, who underwent curative surgery. Body composition was measured by dual-energy X-ray absorptiometry (DXA). Predicted REE from equations in clinical use and derived from DXA and bioelectrical impedance analysis (BIA) were compared against REE measured by 30-min WRIC. Equations included Harris-Benedict, Mifflin-St. Jeor, Food and Agriculture Organization (FAO)/World Health Organization (WHO)/United Nations University (UNU), Henry, Mifflin-St. Jeor_DXA, and FAO/WHO/UNU_BIA. Paired sample t-test, Lin's concordance correlation coefficient, and Bland-Altman analysis were used to determine the agreement between measured REE_WRIC and predicted REE. Accuracy was defined as the percentage of predicted REE values that fell within ± 10% of REE_WRIC.

Results: Mean (SD) REE_WRIC was 1710 kcal/d (353), and respiratory quotient was 0.79 (0.05). Most equations underestimated REE. On average, Harris-Benedict, Henry, and FAO/WHO/UNU_BIA showed the best overall agreement with REE_WRIC. However, these equations showed low accuracy with 65%, 68%, and 62% of predicted REE values within ± 10% of REE_WRIC, respectively.

Conclusions: Most predictive equations tended to underestimate REE in CRC survivors compared with REE_WRIC. The Harris-Benedict, Henry and FAO/WHO/UNU_BIA equations showed both best accuracy and agreement with WRIC. They were still inaccurate, with individual variability for a relevant part of the sample. Future studies need to develop improved predictive equations for CRC survivors. This study was registered at clinicaltrials.gov as NCT01570010 (https://clinicaltrials.gov/study/NCT01570010?locStr=Norway&country=Norway&cond=).

Background: Optimal evidence-based dietary recommendations for dietary fiber have not been established.

Objective: Conduct a systematic review of fiber and gut motility (laxation) in non-infants with normal bowel function.

Methods: We searched PubMed, Embase, and CINAHL from inception through 4 March, 2025, and existing systematic review reference lists. We included randomized controlled trials (RCTs) in the general population without bowel dysfunction that compared fiber amounts or types and assessed stool consistency, fecal weight, fecal frequency, or gut transit time. We categorized fibers according to their solubility, viscosity, and fermentability and performed hierarchical Bayesian regression models and spline analyses across reported total and added fiber intake doses, with sub-analyses by fiber type. We assessed study risk of bias and strength of evidence (SoE).

Results: We identified 113 eligible trials, with low or moderate risk of bias. Models provided moderate SoE that increasing fiber intake (per g/day total fiber) yields softening stool consistency (0.013 units, 95% credible interval [CrI] 0.009, 0.016 on the Bristol Stool Scale), increasing total fecal weight (1.76 g/day, 95% CrI 1.58, 1.94) and dry fecal weight (0.47 g/day, 95% CrI 0.42, 0.51), increasing fecal frequency (0.053 additional bowel movements/week, 95% CrI 0.042, 0.065), and shortening gut transit times (-0.24 hour, 95% CrI -0.36, -0.12). Associations between fiber intake and outcomes varied across fiber doses and type. Low solubility and low fermentability fibers had the strongest associations with laxation outcomes, with low to medium SoE. However, findings are indirect, based on models and there is insufficient evidence in specific sub-populations.

Conclusions: RCTs support small to modest effects of dietary fiber on laxation in generally healthy people with normal bowel function. Low solubility and low fermentability fibers yielded the strongest effects. Future studies should better characterize fiber properties, assess wider ranges of fiber doses, and comprehensively report participants' total and background fiber intake.

Registry number: Registered with PROSPERO (CRD42024522380).

Background: Muscle disuse leads to muscle atrophy that has been attributed to declines in basal and postprandial muscle protein synthesis (MPS) rates. Leucine regulates MPS and may attenuate disuse-induced declines in MPS rates and muscle mass.

Objectives: The purpose of this study was to evaluate the capacity of leucine supplementation to attenuate disuse-induced declines in MPS rates and muscle mass in young and older adults.

Methods: In a randomized, double-blind, parallel-group design, 24 young (23 ± 4 y) and 24 older (69 ± 4 y) recreationally active adults (equal sex distribution) underwent 3 d of unilateral knee immobilization (leg casting) and received a leucine [group of adult study participants who supplemented with 5 g of leucine 3 × daily with each main meal during 3 d of unilateral knee immobilization by means of a full leg cast (LEU)] or energy-matched carbohydrate [group of adult study participants who supplemented with 5 g of carbohydrate 3 × daily with each main meal during 3 d of unilateral knee immobilization by means of a full leg cast (PLA)] supplement (5 g, 3 × daily). Preimmobilization and postimmobilization, quadriceps muscle cross-sectional area (CSA) was assessed in the immobilized (IM) and nonimmobilized (NO-IM) leg by computed tomography. MPS rates were assessed in both legs during immobilization via ²H₂O coupled with saliva, blood, and muscle biopsy sampling.

Results: In young and older adults, MPS rates were ∼15% and ∼23% lower in the IM compared with NO-IM leg (1.28 ± 0.29 compared with 1.50 ± 0.26 and 1.10 ± 0.16 compared with 1.46 ± 0.28%/d, respectively; leg: both P < 0.001), with no differences between LEU compared with PLA treatments (treatment: P = 0.932 and P = 0.742, respectively). CSA decreased by ∼1.2% and ∼1.1% in the IM leg in young and older adults (from 7162 ± 1148 to 7076 ± 1129 mm² and from 5813 ± 1092 to 5750 ± 1096 mm², respectively; leg × time interaction: both P < 0.001), with no differences between LEU compared with PLA (treatment: P = 0.374 and P = 0.998). IM leg MPS rates were lower in older compared with young adults [difference: -0.18 (95% confidence interval: -0.31, -0.04) %/d; P = 0.013]. No differences were observed in the absolute (mm²) or relative (%) decline in CSA between young and older adults (both P > 0.05).

Conclusions: Leucine supplementation does not attenuate the decline in daily MPS rates or muscle mass during short-term limb immobilization in young or older adults. Clinical Trial Register No. (Netherlands Trial Register): NL-OMON45771.

Background: Light-to-moderate alcohol consumption has been linked to improved insulin resistance and lower type 2 diabetes (T2D) risk predominantly in females but not males. Potential mechanisms underlying this sex difference remain unclear.

Objectives: This study evaluated associations of sex-specific alcohol-associated metabolomic signatures (AMSs) with insulin resistance and T2D risk in United States Hispanic/Latino adults.

Methods: We analyzed serum metabolome data in the Hispanic Community Health Study/Study of Latinos, a prospective, multicenter, community-based study of Hispanics/Latinos, aged 18 to 74 y old, enrolled from 4 United States metropolitan areas between 2008 and 2011. Sex-specific AMSs were developed using an elastic net to identify serum metabolites uniquely associated with alcohol consumption in females (n = 2747) and males (n = 1737) without diabetes at baseline, respectively, excluding heavy drinkers. Poisson regression was used to examine the cross-sectional associations of AMSs with insulin resistance (homeostasis model assessment of insulin resistance ≥2.5) and the prospective associations of AMSs with T2D risk in females (n = 2265) and males (n = 1290) over ∼6 y, adjusting for demographic, socioeconomic, and behavioral factors.

Results: We identified 40 and 54 metabolites uniquely associated with light-to-moderate alcohol consumption in females and males, respectively. Cross-sectionally, female-specific AMS (FAMS) was inversely associated with insulin resistance and various T2D-related metabolic traits in females, whereas male-specific AMS was positively associated with insulin resistance and metabolic traits in males. Prospectively, females in the highest quartile of FAMS had ∼82% (95% confidence interval: 70%, 89%) lower T2D risk compared with those in the lowest quartile. The favorable association between alcohol consumption and risk of T2D was attenuated after adjusting for FAMS. In males, there was no statistically significant association between male-specific AMS and T2D risk.

Conclusions: Our results suggested distinct blood metabolomic signatures associated with alcohol consumption in females and males, which might contribute to sex differences in the relationship between alcohol consumption and T2D.

Background: Limited evidence exists for effect modification of genetic characteristics on the associations of food consumption and incident type 2 diabetes (T2D).

Objectives: We aimed to investigate whether the food-T2D association would vary by genetic susceptibility to metabolic traits.

Methods: We analyzed data from 9542 incident T2D cases and a subcohort of 12,477 participants nested within the 340,234-participant cohort recruited in 1991-1998 and followed up for 10.9 y on average in 8 European countries. Polygenic risk scores (PRSs) for higher body mass index, insulin resistance, and T2D were constructed. Fifteen dietary variables potentially associated with T2D, obtained with cohort-specific self-reported dietary assessment, were examined: fruits, green leafy vegetables, root vegetables, wholegrains, rice, legumes, nuts and seeds, fermented dairy, red meat, processed meat, fish, eggs and egg products, sugar-sweetened beverages, coffee, and tea. A cross-product term between each PRS and each food/beverage was evaluated by genotyping chip and country with Prentice-weighted Cox regression for incident T2D, and stratum-specific estimates were meta analyzed, followed by Benjamini-Yekutieli multiple-testing correction.

Results: Accounting for multiple tests of 3 PRSs × 15 dietary items, no evidence of statistical interaction was evident on either a multiplicative or additive scale, with exp(β for a multiplicative interaction) (95% confidence interval) ranging from 0.84 (0.64, 1.10) (root vegetables and PRS for T2D) to 1.45 (0.78-2.76) (fish and PRS for T2D).

Conclusions: Genetic susceptibility to high-risk metabolic traits did not modify the diet-T2D associations in European populations. Acknowledging the limitations of current PRS-based methods to detect gene-diet interactions, research should continue into the potential for precision nutrition and tailored food-based dietary guidance for T2D prevention.

Background: Although measures of blood and tissue fatty acid (FA) concentrations are available, objective measures of dietary FA densities (grams per kilocalories) are generally lacking.

Objectives: We aimed to explore the development of biomarkers for specific and composite dietary FA densities, not including contributions from dietary supplements, using metabolite profiles from serum and 24-h urine, along with separately measured serum phospholipid FA concentrations in the Women's Health Initiative.

Methods: Potential biomarker equations were based on linear regression of feeding study dietary FA densities on metabolite concentrations, each log-transformed, among participants in a habitual-diet human feeding study (n = 153) within the Women's Health Initiative. Corresponding biomarker equations were also considered for total SFA, MUFA, and PUFA densities and for total n-3 and n-6 PUFA densities. Dietary FA density estimates derived from these equations were evaluated by correlation with feeding study intake densities, and by other important biomarker criteria.

Results: Regression cross-validated R² values >30% for specific SFAs were 64.7 butyric, 60.9 caprioc, 48.7 caprylic, 53.0 capric, 39.9 lauric, 61.0 myristic, 42.2 palmitic, 34.2 stearic, 34.8 arachidic, 49.9 decosanoic; for specific MUFAs were 31.3 oleic; and for specific PUFAs were 51.7 linoleic, 50.1 α-linolenic, 39.7 arachidonic, 40.2 EPA, 53.5 decosapentaenoic acid, and 47.9 DHA. Corresponding values were 46.4, 52.8, 46.1, and 52.4 for total SFA, total PUFA, total n-3, and total n-6 densities. Many FA density equations had contributions from multiple metabolites, mostly serum metabolites, and from total energy expenditure. Sensitivity and specificity criteria are plausibly satisfied for proposed biomarkers, based on the feeding study design and on the sets of selected metabolites.

Conclusions: Combinations of log-transformed metabolite concentrations can lead to objective intake density estimates for multiple FAs in the diets of United States postmenopausal females, with relevance to the reliable study of dietary FA densities and chronic disease risk. This study was registered at clinicaltrials.gov as NCT00000611 https://clinicaltrials.gov/study/NCT00000611).

Background: Malnutrition is common in critically ill patients and is associated with poor clinical outcomes. It can be more accurately diagnosed using integrative tools.

Objectives: This study aimed to pool malnutrition prevalence in critically ill adults and estimate the accuracy of different tools and its association with clinical outcomes.

Methods: We conducted a systematic review and meta-analysis of observational studies reporting malnutrition prevalence in patients admitted to intensive unit care (ICUs). PubMed, Embase, Scopus, and Web of Science were searched until 18 September, 2024, without any restrictions. Studies using ≥1 integrative tool were eligible. Outcomes tested for predictive validity included ICU or hospital mortality and length of stay. Two reviewers independently screened studies and extracted data. Risk of bias and publication bias were assessed. Meta-analyses were performed using a random-effects model. Concurrent validity of global leadership international malnutrition (GLIM) and Academic Nutrition and Dietetics and American Society of Parenteral and Enteral Nutrition (AND-ASPEN) criteria were tested with subjective global assessment as reference. Certainty of evidence was rated by Grading of Recommendations Assessment, Development, and Evaluation.

Results: Sixty-six studies were included (66.7% prospective cohorts, 83.3% single-center, and 24.2% from Brazil). Malnutrition prevalence (n = 64 studies, 19,718 patients) was 45.0% [95% confidence interval (CI): 41.0%, 50.0%, I² = 97.4%], influenced by the ICU type, continent, and diagnostic tool. GLIM showed specificity of 81.2% (95% CI: 74.1%, 86.1%) and sensitivity of 86.7% (95% CI: 80.1%, 90.9%). AND-ASPEN specificity and sensitivity were 84.2% (95% CI: 78.5%, 87.6%) and 84.8% (95% CI: 79.4%, 88.2%), respectively. Malnutrition was associated with higher mortality risk (relative risk = 2.00, 95% CI: 1.68, 2.39, I² = 72.8%), longer ICU stay [mean difference (MD) = 1.60 d, 95% CI: 0.54, 2.67, I² = 96.6%], and longer hospital stay (MD = 4.04 d, 95% CI: 0.60, 7.47, I² = 97.2%). Most studies had a high risk of bias, and the certainty of evidence was very low for all outcomes.

Conclusions: The prevalence of malnutrition was 45%, associated with an increased risk of death and longer ICU and hospital stays, but the certainty of evidence was very low.