ABSTRACT
Background: This is a systematic review and meta-analysis to compare the efficacy of intermittent energy restriction (IER) vs. continuous energy restriction (CER) on weight loss, body composition, blood pressure, and other cardiometabolic risk factors in patients with metabolic syndrome (MetS) risk factors. Methods: We searched and screened PubMed, Embase, Cochrane Library, and Web of Science from inception to May 8, 2022 for randomized controlled trials. Two review authors independently selected studies, extracted data, assessed quality and risk of bias and cross-checked extracts to resolve discrepancies when required. We expressed effect size as mean difference (MD) and 95% confidence interval (CI). The major outcome was the improvement of MetS risk factors, including changes in waist circumference (WC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-c), blood pressure (BP), and fasting plasma glucose (FPG) levels. The secondary outcomes were body weight (BW), body mass index (BMI), body fat (BF), fat free mass (FFM), hip circumference (HC), fasting insulin (FINs), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-c). Results: The meta-analysis included 16 articles (20 trials) with a total of 1,511 participants. All studies had a low risk of bias for random sequence generation. The IER and CER intervention equally improved MetS risk factors WC (MD = -0.47, 95% CI [-1.19, 0.25]), TG (MD = -0.02 mmol/L, 95% CI [-0.11, 0.07]), FPG (MD = -0.02 mmol/L, 95% CI [-0.10, 0.05]) and BP (systolic blood pressure: MD = 0.93 mmHg, 95% CI [-2.74, 4.61]; diastolic blood pressure: MD =1.15 mmHg, 95% CI [-0.24, 2.55]), but HDL-c (MD = 0.03 mmol/L, 95% CI [0.01, 0.05]) was significant improved in IER when compared with CER. For second outcomes, BW (MD = -0.8 kg, 95% CI [-1.26, -0.33]), BF (MD = -0.75 kg, 95% CI [-1.73, -0.13]) and FFM (MD = -0.49 kg, 95% CI [-0.92, -0.05]) were also significant improved in IER, and not for other outcomes. Conclusion: Both IER and CER could improve MetS biomarkers, but IER was more effective than CER in the improvement of HDL-c only. For secondary outcomes, IER was also more effective for BW, BF and FFM, but there were no differences in effects for other outcomes.
ABSTRACT
Objective: This study's purpose was to investigate the effects of different intensities of physical activity on cardiovascular metabolism in obese children and adolescents based on an isochronous replacement model. Methods: A total of 196 obese children and adolescents (mean age, 13.44 ± 1.71 years) who met the inclusion criteria and attended a summer camp from July 2019 to August 2021 were recruited for this study, and all subjects wore a GT3X + triaxial motion accelerometer uniformly around the waist to record physical activity levels. We collected the subjects' height, weight, and cardiovascular risk factors such as waist circumference, hip circumference, fasting lipids, blood pressure, fasting insulin, and fasting glucose before and after 4 weeks of camp and constructed cardiometabolic risk score (CMR-z). We analyzed the effects of different intensities of physical activity on cardiovascular metabolism in obese children using isotemporal substitution model (ISM). Results: After 4 weeks, cardiovascular risk factors such as body weight, waist circumference, triglyceride, and total cholesterol were reduced in adolescents with obesity (p <0.01), and CMR-z was also reduced (p <0.01). ISM analysis revealed that all sedentary behavior (SB) replacement with 10 min of light physical activity (LPA) reduced CMR-z [ß = -0.10, 95% CI (-0.20, -0.01)]; 10-min of moderate physical activity (MPA) replacement of SB reduced CMR-z [ß = -0.32, 95% CI (-0.63, -0.01)]; 10-min of vigorous physical activity (VPA) replacement of SB reduced CMR-z [ß = -0.39, 95% CI (-0.66, -0.12)]. Conclusion: Replacement of SB with 10 min of LPA, MPA, and VPA were all effective in improving cardiovascular risk health, respectively, but MPA or VPA was more effective.
ABSTRACT
Background: Intermittent energy restriction (IER) and continuous energy restriction (CER) are increasingly popular dietary approaches used for weight loss and overall health. These energy restriction protocols combined with exercise on weight loss and other health outcomes could achieve additional effects in a short-term intervention. Objectives: To evaluate the effects of a 4-week IER or CER program on weight, blood lipids, and CRF in overweight/obese adults when combined with high-intensity interval training (HIIT). Methods: Forty-eight overweight/obese adults [age: 21.3 ± 2.24 years, body mass index (BMI): 25.86 ± 2.64 kgâ m-2] were randomly assigned to iER, cER, and normal diet (ND) groups (n = 16 per group), each consisting of a 4-week intervention. All of the groups completed HIIT intervention (3 min at 80% of VÌO2max followed by 3 min at 50% of VÌO2max ), 30 min/training sessions, five sessions per week. iER subjects consumed 30% of energy needs on 2 non-consecutive days/week, and 100% of energy needs on another 5 days; cER subjects consumed 70% of energy needs; and ND subjects consumed 100% of energy needs. Body composition, waist circumference (WC) and hip circumference (HC), triglyceride (TG), total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-c), high-density lipoprotein-cholesterol (HDL-c), and cardiorespiratory fitness (CRF) were measured before and after the intervention. Results: Of the total 57 participants who underwent randomization, 48 (84.2%) completed the 4-week intervention. After intervention body composition and body circumference decreased in three groups, but no significant differences between groups. The iER tends to be superior to cER in the reduction of body composition and body circumference. The mean body weight loss was 4.57 kg (95% confidence interval [CI], 4.1-5.0, p < 0.001) in iER and 2.46 kg (95% CI, 4.1-5.0, p < 0.001) in iER. The analyses of BMI, BF%, WC, and HC were consistent with the primary outcome results. In addition, TG, TC, HDL-c, and CRF improved after intervention but without significant changes (p > 0.05). Conclusion: Both IER and CER could be effective in weight loss and increased CRF when combined with HIIT. However, iER showed greater benefits for body weight, BF%, WC, and HC compared with cER.
ABSTRACT
OBJECTIVES: Metabolic syndrome (MetS) is systemic metabolic disease that results from insulin resistance or obesity. Numerous meta-analyses have investigated the effect of exercise on different populations, but none were aimed at the effect of aerobic exercise alone on obese children. This review systematically assessed and performed a meta-analysis on the effect of aerobic exercise on obese children with MetS. CONTENT: MEDLINE via PubMed, Embase, SPORTDiscus, and the Cochrane library were searched and screened from inception to 20 October 2020 for randomized controlled trials. The inclusion criteria were obese children who met the criteria for MetS and aged 5-19 years old in an aerobic exercise group. The meta-analysis included eight trials with a total of 197 participants. Aerobic exercise significantly improved the waist circumference (mean difference [MD]=-3.97; 95% confidence interval [CI]=-6.12 to -1.83; p<0.01), body mass index (standardized MD [SMD]=-0.5; 95% CI=-0.70 to -0.29; p<0.01), triglyceride (SMD=-24.6; 95% CI=-33.85 to -15.35; p<0.01), high-density lipoprotein cholesterol (SMD=2.36; 95% CI=0.44 to 4.27; p<0.01), and systolic blood pressure (SMD=-6.90; 95% CI=-10.46 to -3.35; p<0.01). SUMMARY: Based on the results of this meta-analysis, during the intervention period of the included studies, aerobic exercise alone mainly affected the lipoprotein, blood pressure, and body dimensions but cannot completely cure the MetS of obese children. OUTLOOK: The effects of different types of aerobic exercise on obese children with MetS and exercise dose to cure the MetS of obese children needs to be further studied.
