Journal of the American College of Nutrition最新文献

Objective: The present randomized, placebo-controlled study aimed to assess the long-term safety and perceivable mental acuity benefits of EnXtra^® in healthy individuals.Methods: Study participants were administered EnXtra^® with or without caffeine for a period of 12 weeks. The cardiovascular safety was evaluated by assessing change in QT interval, blood pressure and heart rate. Further, other efficacy variables evaluated were change in perceived alertness and calmness by Bond and Lader mood scales, Sleep disturbance by Pittsburgh sleep quality Index and daytime sleepiness by Epworth sleepiness scale.Results: None of the study group showed any significant change in the ECG or haemodynamic parameters as compared to baseline (p > 0.05). Post consumption, alertness and calmness scores were significantly increased in the EnXtra^®, and EnXtra^® plus caffeine group (p < 0.001) as compared to placebo. Daytime sleep scores decreased in the EnXtra^® group however change was not significant. Sleep quality remained undisturbed in all three arms.Conclusion: The findings demonstrated the psychostimulant efficacy of EnXtra^® with no safety concerns on long-term usage.

Background: The associations of coffee consumption with the circulating level of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) remains controversial. We conducted a meta-analysis of observational studies to sum up the existing evidence about this matter.Methods: A comprehensive literature-search up to January 2020, using PubMed, Embase and Web of Science databases, was conducted to identify the relevant observational studies that examined the associations of coffee consumption with the circulating level of ALT and AST. The standard mean difference (SMD) for the level of ALT and AST, odds ratio (OR) for the elevated ALT and AST and their corresponding 95% CIs for the highest versus lowest categories of coffee intake were determined.Results: A total of 19 observational studies, which involved 222,067 individuals, were included in this meta-analysis. The combined SMD suggested that coffee consumption was associated with a lower level of ALT (SMD = -0.14, 95% CI: -0.22 to -0.06; p = 0.001) and AST (SMD = -0.17, 95% CI: -0.20 to -0.13; p < 0.001), respectively. Meanwhile, the overall multivariable adjusted OR showed that coffee consumption was inversely associated with the elevated ALT (OR = 0.69, 95% CI: 0.60 to 0.79; p < 0.001) and AST (OR = 0.62, 95% CI: 0.48 to 0.81; p < 0.001), respectively.Conclusion: The results of this meta-analysis suggest that coffee consumption is inversely associated with the circulating level of ALT and AST, and elevated ALT and AST. More randomized controlled trials are needed to elaborate the concerned issues.

Objective: The purpose of this ecological study was to characterize the community food environment according to the socioeconomic condition of census tracts (CTs) in the urban area of a medium-sized city of southeastern Brazil in 2016.Method: Food establishments were identified on the streets covered by raters and information about type was collected through objective assessment. Geocoding was carried out from address observed by raters. Food establishments were categorized into establishments with predominant sale of natural or minimally processed foods, mixed establishments, and establishments with predominant sale of ultra-processed foods. The distribution of the number of establishments, by category, was evaluated according to tertiles of per capita income of the CT. The kernel estimation was used to analyze the density of establishments by category. The spatial pattern of the categories of establishments was investigated using the univariate Ripley's K-function.Results: A total of 656 establishments were evaluated. In all, 11.1% had predominant sale of natural or minimally processed foods, 44.5% were mixed, and 44.4% had predominant sale of ultra-processed foods. The average of establishments with predominant sale of natural or minimally processed foods, of ultra-processed foods, and all categories increased according to the income of the CT. There was a clustering of all categories of establishments in high-income CTs downtown. However, peripheral and low-income CTs were composed of a higher number of mixed establishments or those with predominant sale of ultra-processed foods than establishments with predominant sale of natural or minimally processed foods.Conclusions: On average, the number of all categories of establishments increased according to the per capita income of the CT and were clustered in central and higher-income regions of the city. These findings may have practical implications for the development of public policies to increase the availability of healthy foods and to reduce the sale of unhealthy foods.

Background: Increased soft-drink consumption has contributed to poor calcium intake with 90% of adolescent girls consuming less than the RDA for calcium.Purpose/objectives: The purpose of this investigation was to determine the independent and additive effects of two interventions (milk and resistance training) on nutrient adequacy, body composition, and bone health in adolescent girls.Methods: The experimental design consisted of four experimental groups of adolescent girls 14-17 years of age: (1) Milk + resistance training [MRT]; n = 15; (2) Resistance training only [RT]; n = 15; (3) Milk only [M] n = 20; (4) Control [C] n = 16. A few significant differences were observed at baseline between the groups for subject characteristics. Testing was performed pre and post-12 week training period for all groups. Milk was provided (3, 8 oz servings) for both the MRT and the M groups. The MRT group and the RT groups performed a supervised periodized resistance training program consisting of supervised one-hour exercise sessions 3 d/wk (M, W, F) for 12 wk. Baseline dietary data was collected utilizing the NUT-P-FFQ and/or a 120 item FFQ developed by the Fred Hutchinson Cancer Research Center (Seattle, Washington). Body composition was measured in the morning after an overnight fast using dual-energy X-ray absorptiometry (DXA) with a total body scanner (Prodigy^TM, Lunar Corporation, Madison, WI). A whole body scan for bone density and lumbar spine scans were performed on all subjects. Maximal strength of the upper and lower body was assessed via a one-repetition maximum (1-RM) squat and bench press exercise protocols. Significance was set at P ≤ 0.05.Results: Significant differences in nutrient intakes between groups generally reflected the nutrient composition of milk with greater intakes of protein and improved nutrient adequacy for several B vitamins, vitamin A, vitamin D, calcium, magnesium, phosphorus, potassium, and zinc. Mean calcium intake was 758 and 1581 mg/d, in the non-milk and milk groups, respectively, with 100% of girls in the milk groups consuming > RDA of 1300 mg/d. There were no effects of milk on body composition or muscle performance, but resistance training had a main effect and significantly increased body mass, lean body mass, muscle strength, and muscle endurance. There was a main effect of milk and resistance training on several measures of bone mineral density (BMD). Changes in whole body BMD in the M, RT, MRT, and CON were 0.45, 0.52, 1.32, and -0.19%, respectively (P < 0.01).Conclusions: Over the course of 12 weeks the effects of 1300 mg/d of calcium in the form of fluid milk combined with a heavy resistance training program resulted in the additive effects of greater nutrient adequacy and BMD in adolescent girls. While further studies are needed, combining increased milk consumption with resistance training appears to optimize bone hea

Objective: The aim of this research was to explore the complexity of college student food insecurity through eating patterns, food assistance, and health of food-insecure university students.

Methods: A mixed-methods approach utilizing qualitative focus groups and individual interview data and survey quantitative data was used. All data collection took place on campus at a large Midwestern university in the Spring semester of 2018. Participants were Midwestern university students (n = 30), freshman to graduate level classified, with very low food security (USDA-Six Item Short Form).

Results: Seven percent (n = 2) were currently enrolled in food assistance programming (SNAP), and 30% (n = 9) reported family enrollment growing up (WIC and SNAP). Seven major themes emerged highlighting nutritional habits, food adaptations, health and well-being impacts, and additional campus programming addressing food assistance. Data triangulation informed a complexity diagram with the major categories of student characteristics of food insecurity, campus resource barriers, additional student needs, health and well-being impacts, and student adaptations and coping influencing the complexity surrounding student food insecurity.

Conclusions: College student food insecurity is multifaceted and complex. Common themes emerged among both individual-level factors and university structures, providing a deeper understanding of both the complexity and contributors to the college student experience. Further research and intervention are needed to explore this phenomenon and address student needs.

Background: Potassium intake deficiency is a chronic issue in the US and many other countries. Possible causes of the deficiency are understudied.Objective: This study examined potassium deficiency in the US population and possible causes for the new trend.Methods: Serum potassium data of 28,379 men and 29,617 women between ages 12 and 80 years old who participated in the US National Health and Nutrition Examination Survey (NHANES) between 1999 and 2016 were examined. Blood samples were collected by NHANES and blood biochemistry data were measured in designed laboratories. The data were released bi-annually. Possible causes of low potassium intakes were explored.Results: There was an apparent decline of serum potassium in the US population between ages 12 and 80 years from 1999 to 2016. Annual average serum potassium concentrations changed from 4.14 ± 0.01 to 3.97 ± 0.01 mmol/l during this period. Hypokalemia prevalence in the US rose from 3.78%±0.68% to 11.06%±1.08% during this period with a higher hypokalemia prevalence in non-Hispanic black than in non-Hispanic white persons. It is possible that declining potassium concentration in food sources in the US contributed to lower potassium intake and increasing potassium deficiency.Conclusion: The rising trend of hypokalemia prevalence in the US population between 1999 and 2016 is alarming. Renewed efforts to reduce potassium intake deficiency in the US at population level are needed. The impact of possible decreasing crop available potassium levels and increasing consumption of processed food on the potassium deficit trend in the US are possible explanations for the rise in hypokalemia prevalence and require further study.

Introduction: Energy drink (ED) intake could initiate physiological changes owing to its stimulant characteristics and, it improves endurance and athletic performance. We evaluated the acute effects of ED on autonomic heart rate (HR) control during recovery after a session of submaximal aerobic exercise.Method: The study was completed by submitting 29 healthy males between 18 and 30 years old to three conventions: (A) Maximum exercise test by the adapted Bruce protocol; (B) Placebo protocol (PP) - water intake 15 minutes prior to exercise, rest in dorsal decubitus for 15 minutes followed by 5 minutes of treadmill running at 1% inclination, initial speed of 5 km/h for 5 minutes 25 minutes with 60% of the velocity consistent to the maximum oxygen consumption (VO2max), and finally 60 minutes of recovery at rest in the supine position; (C) Experimental protocol (PE) - similar to PP previously, but with ED intake 15 minutes before physical exercise. The time, frequency and geometric indexes of HR variability (HRV) were inspected before and after exercise.Results: There was a significant (p < 0.05, <5%) effect on the HRV index (HR-nu and ms², LF-nu and ms², LF/HF, SD1, SDNN and RMSSD), indicating a reduction in HRV in the first 5 minutes after exercise in both protocols (PP and PE). Yet, no protocol interaction was detected, suggesting no effect of ED on HRV throughout recovery after submaximal aerobic exercise.Conclusion: There was no significant effect of ED on the autonomic control of HR in the recovery phase after submaximal aerobic exercise.

Obesity is related to the amplified risk of developing hepatocellular cancer, but its outcome on hepatocellular cancer-related mortality remains uncertain. Hence, the present study aimed to perform a meta-analysis study to evaluate the relationship between weight and hepatocellular cancer-related deaths. Through a systematic literature search up to December 2019, 7 observational studies with 2,349,834 subjects, 4834 hepatocellular cancer-related deaths were identified reporting relationships between body mass index (BMI), and hepatocellular cancer-related mortality. Odd ratio (OR) with 95% confidence intervals (CIs) was calculated comparing obese, BML > 30kg/m², and overweight, BMI, 25-29.9 kg/m² to subjects with normal BMI using the dichotomous method with a random-effect model. In obese subjects, males (OR, 1.84; 95% CI, 1.25-2.70) and females (OR, 1.26; 95% CI, 1.11-1.44), had higher hepatocellular cancer-related mortality compared to normal BMI subjects. However, overweight males (OR, 1.12; 95% CI, 0.98-1.28) and overweight females (OR, 1.06; 95% CI, 0.95-1.18), did not have such risk with moderate heterogeneity. The extent of increased mortality was higher in obese males compared to obese females. The impact of obesity on hepatocellular cancer-related mortality was observed in all populations with less extant in the black population. Based on this meta-analysis, obesity may have an independent relationship with up to the 1.84-fold risk of hepatocellular cancer-related mortality. This relationship was more pronounced in males than in females. Key teaching pointsBeing overweight is related to the amplified risk of developing hepatocellular cancer.Obesity's affect on hepatocellular cancer-related mortality remains uncertain.Based on this meta-analysis, obesity may have an independent relationship with up to the 1.84-fold risk of hepatocellular cancer-related mortality.This relationship was more pronounced in males than in females.

Objective: The optimal dose of β-hydroxy-β-methylbutyrate (HMB) required for decreasing muscle damage remains unknown. Therefore, this study investigated the supplemental effect of low-dose HMB on muscle damage following eccentric contractions (ECCs) of human elbow flexors.Methods: Twenty untrained men (aged 20-26; height, 169.4 ± 5.7 cm; weight, 68.2 ± 11.3 kg; body mass index, 23.7 ± 3.3) completed the double-blind, placebo-controlled, parallel design study. The subjects were randomly assigned to the ingestion of HMB supplement (HMB, n = 10) or placebo group (PL, n = 10). After the subjects of 1.5 g HMB or placebo pills per day for 2 weeks, they performed six sets of 10 ECCs at 100% maximal voluntary contraction (MVC) using dumbbell. Changes in MVC torque, range of motion (ROM), upper arm circumference, muscle soreness, and muscle stiffness were assessed before, immediately after, 1, 2, 3, 5 days after exercise.Results: MVC torque was significantly higher in the HMB group than in the PL group immediately after (HMB, -56.8%; PL, -67.1%) as well as 3 (HMB: -25.5%, PL: -48.7%) and 5 (HMB: -22.5%, PL: -44.0%) days after performing ECCs (p < 0.05). Additionally, ROM was significantly higher in the HMB group than in the PL group immediately after (HMB, -29.8%; PL, -50.5%) and 5 (HMB: -26.1%, PL: -43.3%) days after performing ECCs (p < 0.05). No between-group differences were observed in other muscle damage markers.Conclusion: The low-dose HMB supplementation demonstrated a moderate overall impact and played a beneficial role in muscle dysfunction and joint flexibility following ECCs.