37 research outputs found

    Comparison of effects of diet versus exercise weight loss regimens on LDL and HDL particle size in obese adults

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    <p>Abstract</p> <p>Background</p> <p>Obesity is associated with an atherogenic lipid profile characterized by a predominance of small LDL and HDL particles. Weight loss, by dietary restriction or exercise, increases LDL particle size. Whether these interventions can augment HDL size <it>in conjunction </it>with LDL size remains unknown.</p> <p>Objective</p> <p>This study compared the effects of alternate day fasting (ADF), calorie restriction (CR), and endurance exercise on LDL and HDL particle size in overweight and obese subjects.</p> <p>Methods</p> <p>In a 12-week parallel-arm trial, adult subjects (n = 60) were randomized to 1 of 4 groups: 1) ADF (75% energy restriction for 24-h alternated with ad libitum feeding for 24-h), 2) CR (25% energy restriction every day), 3) exercise (moderate intensity training 3 x/week), or 4) control.</p> <p>Results</p> <p>Body weight was reduced (<it>P </it>< 0.001) by ADF, CR, and exercise (5.2 ± 1.1%, 5.0 ± 1.4%, 5.1 ± 0.9%, respectively). Plasma LDL cholesterol decreased (<it>P </it>< 0.05) with ADF (10 ± 4%) and CR (8 ± 4%), whereas HDL cholesterol increased (<it>P </it>< 0.05) with exercise (16 ± 5%). Integrated LDL particle size was augmented (<it>P </it>= 0.01) by ADF and CR. The proportion of small LDL particles decreased (<it>P </it>= 0.04) with ADF only, and the proportion of large HDL particles increased (<it>P </it>= 0.03) with exercise only.</p> <p>Conclusion</p> <p>These results indicate that dietary restriction increases LDL particle size, while endurance training augments HDL particle size, with minimal weight loss. None of these interventions concomitantly increased both LDL and HDL particle size, however.</p

    Dietary and physical activity adaptations to alternate day modified fasting: implications for optimal weight loss

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    <p>Abstract</p> <p>Background</p> <p>Alternate day modified fasting (ADMF) is an effective strategy for weight loss in obese adults.</p> <p>Objective</p> <p>The objective of this study was to examine the dietary and physical activity adaptations that occur during short-term ADMF, and to determine how these modulations affect rate of weight loss.</p> <p>Methods</p> <p>Sixteen obese subjects (12 women/4 men) completed a 10-week trial consisting of 3 phases: 1) 2-week control phase, 2) 4-week ADMF controlled feeding phase, and 3) 4-week ADMF self-selected feeding phase.</p> <p>Results</p> <p>Body weight decreased (<it>P </it>< 0.001) by 5.6 ± 1.0 kg post-treatment. Energy intake on the fast day was 26 ± 3% of baseline needs (501 ± 28 kcal/d). No hyperphagic response occurred on the feed day (95 ± 6% of baseline needs consumed, 1801 ± 226 kcal/d). Daily energy restriction (37 ± 7%) was correlated to rate of weight loss (<it>r </it>= 0.42, <it>P </it>= 0.01). Dietary fat intake decreased (36% to 33% of kcal, <it>P </it>< 0.05) with dietary counseling, and was related to rate of weight loss (<it>r </it>= 0.38, <it>P </it>= 0.03). Hunger on the fast day decreased (<it>P </it>< 0.05) by week 2, and remained low. Habitual physical activity was maintained throughout the study (fast day: 6416 ± 851 steps/d; feed day: 6569 ± 910 steps/d).</p> <p>Conclusion</p> <p>These findings indicate that obese subjects quickly adapt to ADMF, and that changes in energy/macronutrient intake, hunger, and maintenance of physical activity play a role in influencing rate of weight loss by ADMF.</p

    Effect of intermittent fasting on circulating inflammatory markers in obesity: A review of human trials

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    Obesity is associated with low-grade inflammation. Weight loss, by means of dietary restriction, has been shown to reduce systemic inflammation. Intermittent fasting has recently gained popularity as a weight loss diet, but its effects on inflammatory markers in individuals with obesity have yet to be summarized. Accordingly, this review examined how the two main forms of intermittent fasting, i.e., time restricted eating (TRE) and alternate day fasting (ADF), impact body weight and key circulating inflammatory markers (i.e., C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-alpha), and interleukin-6 (IL-6)), in adults with obesity. Results from this review reveal that TRE with various eating window durations (4–10 h per day) has no effect on circulating levels of CRP, TNF-alpha or IL-6, with 1–5% weight loss. As for ADF, reductions in CRP concentrations were noted when &gt;6% weight loss was achieved. However, ADF had no effect on TNF-alpha or IL-6 concentrations, with this degree of weight loss. Thus, intermittent fasting has little or no effect on key inflammatory markers, but more research is warranted to confirm these preliminary findings

    A meta-analysis comparing the effectiveness of alternate day fasting, the 5:2 diet, and time-restricted eating for weight loss.

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    OBJECTIVE The objective of this meta-analysis was to compare the effectiveness of different intermittent fasting (IF) regimens on weight loss, in the general population, and compare these to traditional caloric energy restriction (CER). METHODS Three databases were searched from 2011 to June 2021 for randomized controlled trials (RCTs) that assessed weight loss and IF, including alternate day fasting (ADF), the 5:2 diet, and time-restricted eating (TRE). A random effect network analysis was used to compare the effectiveness between the three regimens. Meta-regression analysis was presented as weighted mean differences of body weight loss. RESULTS The exploratory random effects network analysis of 24 RCTs (n = 1768) ranked ADF as the most effective, followed by CER and TRE. The meta-analysis showed that IF regimens resulted in similar weight loss to CER (mean difference 0.26 kg, 95% CI: -0.31 to 0.84; p = 0.37). Compliance was generally high (>80%) in trials shorter than 3 months. CONCLUSIONS The present meta-analysis concludes that IF is comparable to CER and a promising alternative for weight loss. Among the three regimens, ADF showed the highest effectiveness for weight loss, followed by CER and TRE. Further well-powered RCTs with longer durations of intervention are required to draw solid conclusions

    Effects of weight loss via high fat vs. low fat alternate day fasting diets on free fatty acid profiles

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    Cardiovascular disease risk is associated with excess body weight and elevated plasma free fatty acid (FFA) concentrations. This study examines how an alternate-day fasting (ADF) diet high (HF) or low (LF) in fat affects plasma FFA profiles in the context of weight loss, and changes in body composition and lipid profiles. After a 2-week weight maintenance period, 29 women (BMI 30–39.9 kg/m2) 25–65 years old were randomized to an 8-week ADF-HF (45% fat) diet or an ADF-LF (25% fat) diet with 25% energy intake on fast days and ad libitum intake on feed days. Body weight, BMI and waist circumference were assessed weekly and body composition was measured using dual x-ray absorptiometry (DXA). Total and individual FFA and plasma lipid concentrations were measured before and after weight loss. Body weight, BMI, fat mass, total cholesterol, LDL-C and triglyceride concentrations decreased (P < 0.05) in both groups. Total FFA concentrations also decreased (P < 0.001). In the ADF-LF group, decreases were found in several more FFAs than in the ADF-HF group. In the ADF-HF group, FFA concentrations were positively correlated with waist circumference. Depending on the macronutrient composition of a diet, weight loss with an ADF diet decreases FFA concentrations through potentially different mechanisms

    Improvements in vascular health by a low-fat diet, but not a high-fat diet, are mediated by changes in adipocyte biology

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    <p>Abstract</p> <p>Background</p> <p>Low-fat (LF) and high-fat (HF) weight loss diets improve brachial artery flow-mediated dilation (FMD) in obese individuals, although results are conflicting. Moreover, the role that adipose tissue plays in mediating these diet-related effects are unknown.</p> <p>Objective</p> <p>This study examined how modulations in FMD by HF and LF diets relate to changes in adipocyte parameters.</p> <p>Design</p> <p>Obese subjects (n = 17) were randomized to a HF diet (60% kcal as fat) or a LF diet (25% kcal as fat) for 6 weeks. Both groups were restricted by 25% of energy needs.</p> <p>Results</p> <p>Body weight decreased (<it>P <</it>0.05) in both groups (HF: -6.6 ± 0.5 kg, LF: -4.7 ± 0.6 kg). Fat mass and waist circumference were reduced (<it>P <</it>0.05) in the LF group only (-4.4 ± 0.3 kg; -3.6 ± 0.8 cm, respectively). FMD improved (<it>P <</it>0.05) in the LF group (7.4 ± 0.8% to 9.8 ± 0.8; 32% increase) and was impaired in the HF group (8.5 ± 0.6% to 6.9 ± 0.7; 19% reduction). Increases in plasma adiponectin (<it>P <</it>0.05, 16 ± 5%), and decreases in resistin (<it>P <</it>0.05, -26 ± 11%), were shown by the LF diet only. Greater decreases in leptin were observed with LF (-48 ± 9%) versus HF (-28 ± 12%) (<it>P <</it>0.05, diet × time). Increased FMD by the LF diet was associated with increased adiponectin, and decreased fat mass, waist circumference, leptin, and resistin.</p> <p>Conclusion</p> <p>Beneficial modulations in vascular health by LF diets may be mediated by improvements in adipocyte parameters.</p

    Eating disorders in weight-related therapy (EDIT): protocol for a systematic review with individual participant data meta-analysis of eating disorder risk in behavioural weight management

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    The Eating Disorders In weight-related Therapy (EDIT) Collaboration brings together data from randomised controlled trials of behavioural weight management interventions to identify individual participant risk factors and intervention strategies that contribute to eating disorder risk. We present a protocol for a systematic review and individual participant data (IPD) meta-analysis which aims to identify participants at risk of developing eating disorders, or related symptoms, during or after weight management interventions conducted in adolescents or adults with overweight or obesity. We systematically searched four databases up to March 2022 and clinical trials registries to May 2022 to identify randomised controlled trials of weight management interventions conducted in adolescents or adults with overweight or obesity that measured eating disorder risk at pre- and post-intervention or follow-up. Authors from eligible trials have been invited to share their deidentified IPD. Two IPD meta-analyses will be conducted. The first IPD meta-analysis aims to examine participant level factors associated with a change in eating disorder scores during and following a weight management intervention. To do this we will examine baseline variables that predict change in eating disorder risk within intervention arms. The second IPD meta-analysis aims to assess whether there are participant level factors that predict whether participation in an intervention is more or less likely than no intervention to lead to a change in eating disorder risk. To do this, we will examine if there are differences in predictors of eating disorder risk between intervention and no-treatment control arms. The primary outcome will be a standardised mean difference in global eating disorder score from baseline to immediately post-intervention and at 6- and 12- months follow-up. Identifying participant level risk factors predicting eating disorder risk will inform screening and monitoring protocols to allow early identification and intervention for those at risk
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