1.
Isocaloric Substitution of Dietary Carbohydrate Intake with Fat Intake and MRI-Determined Total Volumes of Visceral, Subcutaneous and Hepatic Fat Content in Middle-Aged Adults.
Meisinger, C, Rospleszcz, S, Wintermeyer, E, Lorbeer, R, Thorand, B, Bamberg, F, Peters, A, Schlett, CL, Linseisen, J
Nutrients. 2019;11(5)
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Obesity, a worldwide epidemic due to the availability of many unhealthy food options and limited physical exercise, is a known risk factor for many metabolic disorders. The aim of this study was to investigate the association of carbohydrate intake and isocaloric substitution with different types of fat as determined by magnetic resonance imaging (MRI). The study’s analysis was based on the KORA-FF4 study, the second follow-up study of the KORA Survey S4. A total of 400 individuals participated in the FF4 study, from which 283 participants were included in this analysis. Results indicate an association between fat accumulation at specific anatomic locations and macronutrient composition among the participants. The isocaloric substitution of carbohydrates with fat was associated with higher hepatic (related to the liver) fat content and visceral fat accumulation. Authors conclude that the study’s findings can contribute towards the long-lasting discussion about a diet’s optimal fat content.
Abstract
The present study investigated the association of carbohydrate intake and isocaloric substitution with different types of fat with visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT) and hepatic fat content as determined by magnetic resonance imaging (MRI). Data from 283 participants (mean age 56.1 ± 9.0 years) from the MRI sub study of the KORA FF4 study were included. VAT, SAT and total body fat were quantified by a volume-interpolated VIBE-T1w-Dixon MR sequence. Hepatic fat content was determined as the proton density fat-fraction (PDFF) derived from multiecho-T1w MR sequence. Dietary intake was estimated using information provided by two different instruments, that is, repeated 24-h food lists and a food frequency questionnaire. Replacing total carbohydrates with an isoenergetic amount of total fat was significantly positively associated with VAT and hepatic fat, while there was no significant association with SAT. The multivariable adjusted β-coefficient for replacing 5% of total energy (5E%) carbohydrates with total fat was 0.42 L (95% CI: 0.04, 0.79) for VAT. A substitution in total fat intake by 5E% was associated with a significant increase in liver fat content by 23% (p-value 0.004). If reproduced in prospective studies, such findings would strongly argue for limiting dietary fat intake.
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Untargeted metabolomic on urine samples after α-lipoic acid and/or eicosapentaenoic acid supplementation in healthy overweight/obese women.
Romo-Hualde, A, Huerta, AE, González-Navarro, CJ, Ramos-López, O, Moreno-Aliaga, MJ, Martínez, JA
Lipids in health and disease. 2018;17(1):103
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Eicosapentaenoic acid (EPA - an omega-3 fatty acid) and alpha-lipoic acid (an antioxidant) have both been investigated for their beneficial impacts on weight loss and heart health. The aim of this double-blind randomised placebo-controlled intervention lasting 8 weeks was to assess the effect of dietary supplementation with EPA and alpha-lipoic acid, separately or in combination, and together with a calorie restricted diet, on breakdown products (metabolites) present in the urine. The study recruited a group of 70 healthy overweight/obese sedentary females. Results indicate a higher reduction in body mass index and fat mass in those groups supplemented with alpha-lipoic acid. EPA supplementation had no effect on urinary breakdown products. Authors conclude that alpha-lipoic acid administration has beneficial effects on body weight reduction, mainly through its antioxidant properties.
Abstract
BACKGROUND Eicosapentaenoic acid (EPA) and α-lipoic acid (α-LA) have been investigated for their beneficial effects on obesity and cardiovascular risk factors. In the current research, the goal was to evaluate metabolomic changes following the dietary supplementation of these two lipids, alone or combined in healthy overweight/obese sedentary women following an energy-restricted diet. For this purpose, an untargeted metabolomics approach was conducted on urine samples using liquid chromatography coupled with time of flight mass spectrometry (HPLC-TOF-MS). METHODS This is a short-term double blind placebo-controlled study with a parallel nutritional design that lasted 10 weeks. Participants were assigned to one of the 4 experimental groups [Control, EPA (1.3 g/d), α-LA (0.3 g/d) and EPA+α-LA (1.3 g/d + 0.3 g/d)]. All intervention groups followed an energy-restricted diet of 30% less than total energy expenditure. Clinically relevant biochemical measurements were analyzed. Urine samples (24 h) were collected at baseline and after 10 weeks. Untargeted metabolomic analysis on urine samples was carried out, and principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) were performed for the pattern recognition and characteristic metabolites identification. RESULTS Urine samples were scattered in the PCA scores plots in response to the supplementation with α-LA. Totally, 28 putative discriminant metabolites in positive ionization, and 6 in negative ionization were identified among groups clearly differentiated according to the α-LA administration. Remarkably is the presence of an ascorbate intermediate metabolite (one of the isomers of trihydroxy-dioxohexanoate, or dihydroxy-oxohexanedionate) in the groups supplemented with α-LA. This fact might be associated with antioxidant properties of both α-LA and ascorbic acid. Correlations between phenotypical parameters and putative metabolites of provided additional information on whether there is a direct or inverse relationship between them. Especially interesting are the negative correlation between ascorbate intermediate metabolite and asymmetric dimethylarginine (ADMA) and the positive one between superoxide dismutase (SOD) and α-LA supplementation. CONCLUSIONS This metabolomic approach supports that the beneficial effects of α-LA administration on body weight reduction may be partly explained by the antioxidant properties of this organosulfur carboxylic acid mediated by isomers of trihydroxy-dioxohexanoate, or dihydroxy-oxohexanedionate. TRIAL REGISTRATION Clinicaltrials.gov NCT01138774 .