Purpose: Recent studies have reported a significant association between skeletal muscle, muscle strength and non-alcoholic fatty liver disease (NAFLD). The effect of nutrient intake on the prediction of skeletal muscle mass and strength or its suggested correlation with metabolic diseases has been primarily reported in healthy individuals. The current study explores the association between energy intake and handgrip strength (HGS) in individuals with NAFLD. Methods: Data were obtained from the Korea National Health and Nutrition Examination Surveys 2016-2018. Data from 12,469 participants were extracted and 1,293 men and 1,401 women aged 20 years and older were included in the analyses of patients with NAFLD. The presence of NAFLD was determined using the hepatic steatosis index. To estimate relative skeletal muscle strength, HGS was measured using a digital dynamometer and calculated by adjusting the body mass index of the dominant arm. Study subjects in the NAFLD and nonNAFLD groups were separately categorized according to quartiles of the calculated HGS. Results: We found that individuals with low (EQ1) energy intake had lower odds of HGS compared to subjects with high (EQ4) energy intake, irrespective of their NAFLD status (p < 0.0001). However, the HGS did not differ based on the level of protein or fat intake ratio.Additionally, the effect of energy intake on HGS was more pronounced in men than in women. Conclusion Energy intake was associated with the risk of weak HGS in men with NAFLD.The results indicate that energy intake may be a key factor in nutrition care for NAFLD patients with low muscle function.

Attention deficit hyperactivity disorder (ADHD) has been associated with an elevated risk for obesity but this seems to be paradoxical to the fact that many youths with ADHD have symptoms of hyperactivity. People diagnosed with ADHD tend to have a high risk of developing undesirable diet habits and consequently have health related problems. However, less attention has been paid to obesity in ADHD while many efforts have been devoted to the prevention of childhood obesity in mentally normal people. Hence the purpose of this study was to explore the nutritional status and life habits of children and adolescents with ADHD (n = 76) based on degree of obesity by utilizing the Korean National Health and Nutrition Examination Survey (KNHANES) data from 2005–2013. As results the levels of blood pressure, total triglycerides and the fat intake relative to total energy intake in overweight ADHD group were higher than those in normal weight group. Interestingly, overweight ADHD subjects consumed significantly less amount of iron compared to normal weight ADHD subjects and the level of serum ferritin was lower in the overweight ADHD group (59.0 ng/mL) than in the normal weight ADHD group (47.9 ng/mL). After adjusting total energy intake, total vegetable consumption was 14.3% lower in overweight group compared to the consumption in normal weight group. These results indicate a plausible relationship of iron status and obesity in ADHD subjects but this relationship may not be specific to ADHD. A future study with case-control design is necessary to investigate the association of obesity, nutrient intake, and cognitive/mental status of ADHD.
Adolescent* ; Attention Deficit Disorder with Hyperactivity* ; Blood Pressure ; Case-Control Studies ; Child* ; Energy Intake ; Ferritins ; Food Habits ; Humans ; Iron ; Nutrition Surveys ; Nutritional Status* ; Obesity ; Overweight ; Pediatric Obesity ; Triglycerides ; Vegetables

The purpose of this study was to investigate whether elective course work based nutrition education in university can change students' body composition and eating habits associated with obesity and its related health risk in first-year college students. A total of 38 students agreed and participated in the study. Participants received a series of lecture about obesity, weight management, and concepts of nutrition and food choices for 13 weeks. The students' BMI and body composition, including body fat and muscle contents, were measured. A 24-hour diet recall for two days was performed for food intake analysis, and the questionnaires for dietary behaviors were collected at the beginning and the end of the study. Paired t-test and chi2-test were used for statistical analysis. Data showed that most of the anthropometric parameters including body weight were not significantly changed at the end of the coursework. Interestingly, skeletal muscle contents in both obese (BMI > or = 23) and lean (18.5 < or = BMI < or = 22.9) subjects were significantly increased. Total energy intake was decreased in total subjects after the study. Also, general nutrition behavior of the subjects including enough hydration and utilization of nutrition knowledge were significantly improved during the study period. The total number of responses to doing aerobic exercise was slightly increased after the study, but the average frequency of exercise in each individual was not changed. These results suggest that class-work based nutrition education on a regular basis could be a time and cost effective method for improving body composition and nutritional behavior in general college students.
Adipose Tissue ; Body Composition ; Body Weight ; Diet ; Eating ; Education* ; Energy Intake* ; Exercise ; Humans ; Muscle, Skeletal* ; Muscles ; Obesity ; Surveys and Questionnaires

Manganese (Mn) is an essential micronutrient for human and plays an important role as a cofactor for several enzymes involving fatty acid synthesis, hepatic gluconeogenesis, and oxidative stresses. Also, Mn intake status has been reported to have beneficial effects in reversing metabolic dysfunction including obesity and nonalcoholic steatosis which is linked to mitochondrial dysfunction and oxidative stresses, however, information on dietary Mn intake in Koreans are limited. Hence we investigated the relationship between dietary Mn intake and antioxidant defense factors in healthy and obese subjects. Total of 333 healthy subjects were recruited in the study and were assigned to one of three study groups: a normal group (18.5-22.9), a overweight group (23-24.9), and a obesity group (>25) according to their body mass index (BMI). We assessed Mn intakes (24-hr recall method) and several indicators for antioxidative defenses such as glutathione (GSH), glutathione peroxidase (GPx) and urinary malonaldehyde (MDA). Results showed that body weight and blood pressure of study subjects were increased in dependent of their BMI (p < 0.01). However dietary Mn intakes and oxidative stress biomarkers (GSH, GPx, and MDA) were not significantly different by groups defined by BMI. In correlation analysis adjusting for age, sex and energy intake, dietary Mn intake of the subjects in different BMI categories were not significantly correlated with GSH, GPx, MDA and showed a weak or no association with these oxidative stress markers. In conclusion dietary Mn intake at least in this study has a little or no influence on markers of oxidative status in both healthy and obese subjects.
Adult* ; Biomarkers* ; Blood Pressure ; Body Mass Index* ; Body Weight ; Energy Intake ; Gluconeogenesis ; Glutathione ; Glutathione Peroxidase ; Humans ; Malondialdehyde ; Manganese* ; Micronutrients ; Obesity ; Overweight ; Oxidative Stress*

Purpose: Skeletal muscles display significant heterogeneity in metabolic responses, owing to the composition of metabolically distinct fiber types. Recently, numerous studies have reported that in skeletal muscles, suppression of genes related to fatty acid channeling alters the triacylglycerol (TAG) synthesis and switches the energy substrates. However, such responses may differ, depending on the type of muscle fiber. Hence, we conducted in vitro and animal studies to compare the metabolic responses of different types of skeletal muscle fibers to the deficiency of fatty acyl-CoA synthetase (Acsl)6, one of the main fatty acidactivating enzymes. Methods: Differentiated skeletal myotubes were transfected with selected Acsl6 short interfering RNA (siRNA), and C57BL/6J mice were subjected to siRNA to induce Acsl6 deficiency. TAG accumulation and expression levels of insulin signaling proteins in response to acute glucose supplementation were measured in immortalized cell-based skeletal myotubes, oxidative muscles (OM), and glycolytic muscles (GM) derived from the animals. Results: Under conditions of high glucose supplementation, suppression of the Acsl6 gene resulted in decreased TAG and glycogen synthesis in the C2C12 skeletal myotubes. The expression of Glut4, a glucose transporter, was similarly downregulated. In the animal study, the level of TAG accumulation in OM was higher than levels determined in GM. However, a similar decrease in TAG accumulation was obtained in the two muscle types in response to Acsl6suppression. Moreover, Acsl6 suppression enhanced the phosphorylation of insulin signaling proteins (Foxo-1, mTORc-1) only in GM, while no such changes were observed in OM. In addition, the induction ratio of phosphorylated proteins in response to glucose or Acsl6 suppression was significantly higher in GM than in OM. Conclusion The results of this study demonstrate that Acsl6 differentially regulates the energy metabolism of skeletal muscles in response to glucose supplementation, thereby indicating that the fiber type or fiber composition of mixed muscles may skew the results of metabolic studies.

Dysregulated lipid metabolism, characterized by higher levels of circulating triglycerides, higher levels of small, low density lipoprotein, and accumulation of intracellular lipids, is linked to insulin resistance and related complications such as type 2 diabetes mellitus (T2DM) and cardiovascular diseases (CVD). Considering that various metabolic, genetic, and environmental factors are involved in the development of T2DM and CVD, the causalities of these diseases are often confounded. In recent years, Mendelian randomization (MR) studies coupling genetic data in population studies have revealed new insights into the risk factors influencing the development of CVD and T2DM. This review briefly conceptualizes MR and summarizes the genetic traits related to lipid metabolism by evaluating their effects on the indicators of insulin resistance based on the results of recent MR studies. The data from the MR study cases referred to in this review indicate that the causal associations between lipid status and insulin resistance in MR studies are not conclusive. Furthermore, available data on Asian ethnicities, including Korean, are very limited. More genome-wide association studies and MR studies on Asian populations should be conducted to identify Asian- or Korean-specific lipid traits in the development of insulin resistance and T2DM. The present review discusses certain studies that investigated genetic variants related to nutrient intake that can modify lipid metabolism outcomes. Up-to-date inferences on the causal association between lipids and insulin resistance using MR should be interpreted with caution because of several limitations, including pleiotropic effects and lack of information on genotype and ethnicity.
Asian Continental Ancestry Group ; Cardiovascular Diseases ; Diabetes Mellitus, Type 2 ; Genome-Wide Association Study ; Genotype ; Humans ; Insulin Resistance ; Insulin ; Lipid Metabolism ; Lipoproteins ; Mendelian Randomization Analysis ; Random Allocation ; Risk Factors ; Triglycerides

After publication of the article (Jang & Bu, 2019), the authors recognized clerical errors on page 3 and 4.

Isolating the effects of a single nutrient or food in relation to health outcomes including increased skeletal muscle mass is a challenging task because dietary constituents are highly correlated and synergistic. Hence, diet pattern analysis may be used to investigate the role of certain diets in health outcomes. The present study investigated the dietary patterns and their relationship to skeletal muscle mass in Korean adults. Data were extracted from the 2008–2011 Korea National Health and Nutrition Examination Surveys. To explore the dietary patterns of the study subjects, factor analysis was performed using data obtained from a 24-hour recall. The skeletal muscle index according to dietary pattern scores was then investigated to estimate the changes in skeletal muscle mass. Three patterns were initially identified from the factor analysis. Of these vegetables and fish (VF) pattern was the primary factor with high reliability and was a common factor in sex-separated analyses. The VF pattern scores were positively associated with increased skeletal muscle mass in both men and women. Further analysis according to quartile levels of VF pattern scores showed a positive association between skeletal muscle mass and VF pattern in men but not in women. These results suggest that dietary patterns focused on vegetables and seafoods may contribute to increased skeletal muscle mass in Korean men but that sex difference should be considered in nutrition care for skeletal muscle health.
Adult ; Diet ; Factor Analysis, Statistical ; Female ; Fishes ; Food Habits ; Humans ; Korea ; Male ; Muscle, Skeletal* ; Seafood ; Sex Characteristics ; Vegetables*

The authors made a mistake in presenting an equation for SI calculation on page 223.