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Macronutrient composition and its effect on body composition changes during weight loss therapy in patients with non-alcoholic fatty liver disease: Secondary analysis of a randomized controlled trial.
Lindqvist, C, Holmer, M, Hagström, H, Petersson, S, Tillander, V, Brismar, TB, Stål, P
Nutrition (Burbank, Los Angeles County, Calif.). 2023;110:111982
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Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide and it is closely linked to overweight and obesity. Weight loss leads to an amelioration of NAFLD, which preferably should lead to loss of fat mass while maintaining lean body mass. The aim of this study was to examine if different diet compositions during weight loss therapy were associated with different reductions in abdominal fat mass compared with standard weight loss advice given by a physician. This study was a secondary analysis of data collected in an open-label, randomised controlled trial. The trial examined the effect of two popular weight loss diets, calorie-restricted intermittent fasting (5:2) and a calorie-restricted low-carbohydrate high-fat (LCHF) diet, compared with standard of care (SOC) on reduction in liver fat in 74 persons with NAFLD. Results show that a dietitian-led nutrition counselling treatment with an LCHF or 5:2 diet reduced weight to a higher extent than physician-supported SOC during a 12-wk treatment. Improvements in most of the variables related to body composition parameters and metabolic function were found, independent of dietary composition. Furthermore, during weight loss, visceral fat was mobilized to a greater extent than subcutaneous fat. Authors conclude that further studies are needed with a focus on the effect of diet composition on body composition changes during weight loss.
Abstract
OBJECTIVES Dietary composition may affect body composition during weight loss therapy. We tested the hypothesis of whether dietary macronutrient composition influences the reduction of total abdominal adipose tissue, subcutaneous adipose tissue (SAT), or visceral adipose tissue (VAT) during weight loss. METHODS Dietary macronutrient composition and body composition were analyzed as a secondary outcome of a randomized controlled trial of 62 participants with non-alcoholic fatty liver disease. Patients were randomly assigned to a calorie-restricted intermittent fasting (5:2), calorie-restricted low-carbohydrate high-fat (LCHF), or healthy lifestyle advice (standard-of-care) diet in a 12-wk intervention phase. Dietary intake was assessed by self-reported 3-d food diaries and by characterization of total plasma fatty acid profile. Percentage of energy intake (E%) from different macronutrients was calculated. Body composition was assessed by magnetic resonance imaging and anthropometric measurements. RESULTS The macronutrient composition differed significantly between the 5:2 (fat 36 E% and carbohydrates 43 E%) and the LCHF (fat 69 E% and carbohydrates 9 E%) groups (P < 0.001). Weight loss was similar in the 5:2 and LCHF groups (-7.2 [SD = 3.4] kg versus 8.0 [SD = 4.8] kg; P = 0.44) and significantly larger than for standard of care (-2.5 kg [SD = 2.3]; P < 0.001). The volume of total abdominal fat, adjusted for height, decreased on average by 4.7% (standard of care), 14.3% (5:2), and 17.7% (LCHF), with no significant differences between the 5:2 and LHCF groups (P = 0.32). VAT and SAT, adjusted for height, decreased on average by 17.1% and 12.7% for 5:2, respectively, and by 21.2% and 17.9% for LCHF, with no significant group differences (VAT [P = 0.16] and SAT [P = 0.10]). VAT was mobilized to a greater extent than SAT in all diets. CONCLUSIONS The 5:2 and LCHF diets had similar effects on changes in intraabdominal fat mass and anthropometrics during weight loss. This might indicate that overall weight loss is more important than diet composition to achieve changes in total abdominal adipose tissue, VAT, or SAT. The results of the present study suggest that there is a need for further studies on the effect of diet composition on body composition changes during weight loss therapy.
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The effects of time-restricted eating and weight loss on bone metabolism and health: a 6-month randomized controlled trial.
Papageorgiou, M, Biver, E, Mareschal, J, Phillips, NE, Hemmer, A, Biolley, E, Schwab, N, Manoogian, ENC, Gonzalez Rodriguez, E, Aeberli, D, et al
Obesity (Silver Spring, Md.). 2023;31 Suppl 1:85-95
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Intermittent fasting (IF) involves an alternation of abstinence and consumption of food and caloric beverages over a cycle of hours to days. Time-restricted feeding (in animals) or eating (TRE in humans) is a form of IF that entails restricting eating within a window of 4 to 12 hours per 24-hour cycle and prolonging the time spent in the fasted state to realign eating-fasting patterns with circadian rhythms. The aim of this study was to explore the impact of a 6-month randomised controlled trial of TRE versus standard dietary advice (SDA, active control arm) on bone metabolism and health in a population with at least one component of the metabolic syndrome. This study is a secondary analysis of an open-label 6-month randomised controlled trial in which participants who ate within a time interval > 14 hours per 24-hour cycle (n=54) were randomised to TRE or SDA (active control) with a 1:1 allocation ratio. A total of 42 participants (76% women) with available bone turnover markers and/or bone mass measurements were included in this study. Results show that there weren’t any detrimental effects on bone health outcomes i.e. bone metabolism or bone loss after 6 months of TRE. Additionally, weight loss following a period of TRE might be associated with small bone-sparing effects compared with SDA. Authors conclude that future studies of longer duration (>6 months) assessing multiple bone phenotypes are required in order to confirm the study’s findings and explore the effects of various TRE regimens particularly among individuals at risk for bone fragility such as postmenopausal women and the elderly.
Abstract
OBJECTIVE This study explored the impact of time-restricted eating (TRE) versus standard dietary advice (SDA) on bone health. METHODS Adults with ≥1 component of metabolic syndrome were randomized to TRE (ad libitum eating within 12 hours) or SDA (food pyramid brochure). Bone turnover markers and bone mineral content/density by dual energy x-ray absorptiometry were assessed at baseline and 6-month follow-up. Statistical analyses were performed in the total population and by weight loss response. RESULTS In the total population (n = 42, 76% women, median age 47 years [IQR: 31-52]), there were no between-group differences (TRE vs. SDA) in any bone parameter. Among weight loss responders (≥0.6 kg weight loss), the bone resorption marker β-carboxyterminal telopeptide of type I collagen tended to decrease after TRE but increase after SDA (between-group differences p = 0.041), whereas changes in the bone formation marker procollagen type I N-propeptide did not differ between groups. Total body bone mineral content decreased after SDA (p = 0.028) but remained unchanged after TRE (p = 0.31) in weight loss responders (between-group differences p = 0.028). Among nonresponders (<0.6 kg weight loss), there were no between-group differences in bone outcomes. CONCLUSIONS TRE had no detrimental impact on bone health, whereas, when weight loss occurred, it was associated with some bone-sparing effects compared with SDA.
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Intramyocellular Lipids, Insulin Resistance, and Functional Performance in Patients with Severe Obstructive Sleep Apnea.
Chien, MY, Lee, PL, Yu, CW, Wei, SY, Shih, TT
Nature and science of sleep. 2020;12:69-78
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Obstructive sleep apnoea syndrome (OSA) is characterized by repeated occlusion of the upper airway during sleep, resulting in periods of intermittent hypoxemia [low level of oxygen in blood]. The aim of this study was to (a) investigate the intramyocellular lipids (IMCL) and extramyocellular lipids (EMCL), biochemical data, and functional performance in patients with severe OSA versus controls, and (b) examine the correlations between intra-muscular lipid contents and biochemical and performance variables. This study is a clinical trial that recruited 20 patients with OSA and body mass index(BMI)-matched controls. Results demonstrate that patients with OSA had significantly lower IMCL and EMCL values when compared with their age-, and BMI-matched controls without OSA. Furthermore, compared with controls, patients with OSA had significantly reduced functional performance and exhibited abnormal biochemical data, including glucose and insulin levels and lipid profiles. Authors conclude that additional large-scale clinical trials are required to further explore the complex mechanism between OSA, muscle metabolism, and insulin action.
Abstract
PURPOSE An increasing number of studies have linked the severity of obstructive sleep apnea (OSA) with metabolic dysfunction. However, little is known about the lipid compartments (intramyocellular [IMCL] and extramyocellular [EMCL] lipids) inside the musculature in these patients. The present study was designed to investigate the IMCL and EMCL, biochemical data, and functional performance in patients with severe OSA, and to examine the correlations between intramuscular lipid contents and test variables. PARTICIPANTS AND METHODS Twenty patients with severe OSA (apnea-hypopnea index [AHI]: ≥30/h; body mass index [BMI]: 26.05±2.92) and 20 age- and BMI-matched controls (AHI <5/h) were enrolled. Proton magnetic resonance spectroscopy was used to measure the IMCL and EMCL of the right vastus lateralis muscle. Biochemical data, including levels of fasting plasma glucose, insulin, lipid profiles, and high-sensitivity C-reactive protein (hsCRP), were measured. Insulin resistance index (IR) was calculated using the homeostasis model assessment method. Performance tests included a cardiopulmonary exercise test and knee extension strength and endurance measurements. RESULTS Patients with severe OSA had significantly (P<0.05) lower values of IMCL (14.1±5.4 AU) and EMCL (10.3±5.8 AU) compared to the control group (25.2±17.6 AU and 14.3±11.1 AU, respectively). Patients with severe OSA had significantly higher hsCRP, IR, and dyslipidemia compared with controls (all P<0.05). Furthermore, IMCL was negatively correlated with AHI, cumulative time with nocturnal pulse oximetric saturation lower than 90% (TSpO2<90%) (ρ=-0.35, P<0.05), IR (ρ=-0.40, P<0.05), glucose (ρ=-0.33, P<0.05), and insulin (ρ=-0.36, P<0.05), and positively correlated with lowest oximetric saturation (ρ=0.33, P<0.01). CONCLUSION Skeletal muscle dysfunction and metabolic abnormalities were observed in patients with OSA that did not have obesity. IMCL was positively correlated with aerobic capacity and muscular performance, but negatively correlated with AHI and IR. Large-scale clinical trials are required to explore the complicated mechanism among OSA, intramuscular metabolism, and insulin action. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT00813852.