Aerobic and strength training reduces adiposity in overweight Latina adolescents

School-based high-intensity interval exercise program in children with overweight induce a greater improvements in body composition and physical fitness than moderate-intensity continuous exercise

BACKGROUND

High-intensity interval running exercise (HIIE) is emerging as a time-efficient exercise modality for improving body composition and fitness in comparison with moderate-intensity continuous aerobic exercise (MICE); however, existing evidence is still unclear in children with overweight and thus we compared the effects of HIIE and MICE on body composition, muscular, and cardiorespiratory fitness in children with overweight.

METHODS

In this randomized study, 40 male children with overweight aged 7-10 years were divided into an 8-week exercise regime: (1) HIIE group [n = 20; 2 sets of 15 × 20s at 85-95% maximal aerobic speed (MAS) separated by 15 × 20s recovery at 50% MAS, 3 days per week] and (2) MICE group [n = 20; 30 min at 60-70% MAS, 3 days per week]. Body composition, muscular and cardiorespiratory fitness were assessed before and after the 8-week intervention at similar times and conditions of the day.

RESULTS

Following the 8-week HIIE protocol, weight, BMI, and fat mass decreased significantly (weight: - 1.4% vs. 0.2%, p < 0.05; BMI: - 3.1% vs. - 0.7%, p < 0.05; fat mass: - 7.7% vs. - 1.6%, p < 0.01) as compared with MICE; while the VO2peak and MAS increased significantly in both groups, the increase in HIIE group was significantly greater than that of MICE group (VO2peak: 10.3% vs. 3.5%, p < 0.01; MAS:7.7% vs. 4.5%, p < 0.05). Although significant improvements in muscular fitness were observed in HIIE and MICE groups [counter movement jump (CMJ): 7.8% vs. 5.4%; sprinting ability: - 3.7% vs. - 1.7%], no significant differences were seen between them (p > 0.05).

CONCLUSION

Our findings suggested that school-based HIIE intervention was highly in improving body composition and cardiorespiratory fitness of children with overweight than the MICE regime; however, MICE still provided improvements over time that were just not to the same magnitude of HIIE.

The effects of exercise training on insulin resistance in children and adolescents with overweight or obesity: a systematic review and meta-analysis

Aim

The aim of present meta-analysis was to determine the effects of exercise training (Exe) on insulin resistance (IR) and body weight in children and adolescents with overweight or obesity.

Methods

PubMed, Web of Science, and Scopus were searched for original articles, published through October 2022 that included exercise versus control interventions on fasting glucose, insulin, HOMA-IR, and body weight outcomes in children and adolescents with overweight or obesity. Standardized mean differences (SMD) for fasting insulin, and weighted mean differences (WMD) for fasting glucose, HOMA-IR, body weight (BW), and 95% confidence intervals were determined using random effects models.

Results

Thirty-five studies comprising 1,550 children and adolescents with overweight and obesity were included in the present meta-analysis. Exercise training reduced fasting glucose (WMD=-2.52 mg/dL, p=0.001), fasting insulin (SMD=-0.77, p=0.001), HOMA-IR (WMD=-0.82, p=0.001), and BW (WMD=-1.51 kg, p=0.001), as compared to a control. Subgroup analyses showed that biological sex, intervention duration, type of exercise training, BMI percentile, and health status (with or without diagnosed condition), were sources of heterogeneity.

Conclusion

Exercise training is effective for lowering fasting glucose, fasting insulin, HOMA-IR, and BW in children and adolescents with overweight or obesity and could provide an important strategy for controlling IR and related factors. With clear evidence for the effectiveness of exercise interventions in this vulnerable population, it is important to determine effective approaches for increasing exercise training in children and adolescents with overweight or obesity.

EASO and EFAD Position Statement on Medical Nutrition Therapy for the Management of Overweight and Obesity in Children and Adolescents

INTRODUCTION

This position statement on medical nutrition therapy in the management of overweight or obesity in children and adolescents was prepared by an expert committee convened by the European Association for the Study of Obesity (EASO) and developed in collaboration with the European Federation of the Associations of Dietitians (EFAD).

METHODS

It is based on the best evidence available from systematic reviews of randomized controlled trials on child and adolescent overweight and obesity treatment and other relevant peer-reviewed literature.

RESULTS

Multicomponent behavioural interventions are generally considered to be the gold standard treatment for children and adolescents living with obesity. The evidence presented in this position statement confirms that dietary interventions can effectively improve adiposity-related outcomes. Dietary strategies should focus on the reduction of total energy intake through promotion of food-based guidelines that target modification of usual eating patterns and behaviours. These should target increasing intakes of nutrient-rich foods with a lower energy density, specifically vegetables and fruits, and a reduction in intakes of energy-dense nutrient-poor foods and beverages. In addition, higher intensity, longer duration treatments, delivered by interventionists with specialized dietetic-related skills and co-designed with families, are associated with greater treatment effects.

DISCUSSION

Such interventions should be resourced adequately so that they can be implemented in a range of settings and in different formats, including digital or online delivery, to enhance accessibility.

Type 2 diabetes in children and adolescents: distinct characteristics and evidence-based management

PURPOSE

Since the dramatic rise of obesity prevalence in childhood and adolescence has contributed to increased rates of type 2 diabetes (T2D) in youth, we sought to explore current evidence-based management options for pediatric T2D patients.

METHODS

A comprehensive literature search was performed for studies of T2D in childhood and adolescence until September 2021.

RESULTS

Special pathophysiological and diagnostic characteristics of T2D in this age are presented, while the main focus of the article is on management. Lifestyle interventions with healthy diet and exercise are of great importance for the treatment of T2D in children and adolescents. Metformin and insulin remain the traditional therapeutical means, while liraglutide recently gained indication for children older than 10 years both in USA and Europe. Data on the use, efficacy, safety and therapeutic considerations of other pharmacological treatments in children and adolescents with T2D are critically discussed.

CONCLUSION

Although many new and promising therapeutic strategies have been introduced during recent years for the management of T2D in adults, available therapeutic options for the management of pediatric T2D remain limited.

The Benefits of Resistance Training in Obese Adolescents: A Systematic Review and Meta-analysis

BACKGROUND

Physical activity is essential in acquiring healthy lifestyle behaviors in the early years of maturational development and preventing various diseases. Resistance training (RT) is fundamental for improving body composition and is increasingly recommended for obese adolescents. A systematic review and meta-analysis were performed to synthesize and analyze data on the effects of RT programs in this population, seeking to develop useful recommendations for health and sports professionals.

METHODS

A search was performed using four databases (Web of Science, Scopus, PubMed, and ScienceDirect). According to specific inclusion criteria, twenty-one studies were selected to evaluate the impact of RT on body mass index (BMI), body fat, waist circumference, muscle strength, insulin sensitivity, lean mass and cardiorespiratory fitness.

RESULTS

After the RT programs, the adolescents improved their muscle strength (SMD, 1.44; 95% CI: 0.76-2.12), cardiorespiratory fitness (SMD, 1.09; 95% CI: 0.15-2.04), BMI (SMD, 0.21; 95% CI: 0.07-0.35), waist circumference (SMD, 0.27; 95% CI: 0.06-0.47) and body fat (SMD, 0.20; 95% CI: 0.05-0.34). However, insulin sensitivity (SMD, 0.32; 95% CI: - 0.47 to 1.10) and lean mass (SMD, 0.12; 95% CI: - 0.06 to 0.31) did not reveal any changes. Different RT programs were used but it seems that 2-3 times/week ∼60 min/session of RT for 12 weeks should be recommended for positive changes.

CONCLUSIONS

RT seems to be effective when the objective is to improve muscle strength, cardiorespiratory fitness and can be an efficient strategy to reduce obesity in adolescents by reducing body fat, waist circumference and body mass index. PROSPERO Registration number: CRD42022333411.

On the Relationship Between Well-Being and Exercise Adherence for Children and Adolescents: A Systematic Mini Review

Although the close positive relationship between well-being and exercise adherence has been confirmed by numerous studies, it is still unclear whether this relationship exists for children and adolescents, because previous research mainly focuses on adults. The present review systematically explored the relationship between well-being ranging from individual to social aspects and exercise adherence based on extant studies. Seven studies including both quantitative and qualitative studies were analyzed. The results showed that well-being was not related to exercise adherence as strongly as expected. In some cases, well-being was even negatively associated with exercise adherence. Limited sample size, insensitive measurement of exercise adherence, gender, and mental and physical condition of children and adolescents might partially influence the relationship between well-being and exercise studies. However, the studies at hand are still in their infancy. More studies on the relationship between well-being and exercise adherence are needed for children and adolescents, especially in non-western countries.

Resistance training effectiveness on body composition and body weight outcomes in individuals with overweight and obesity across the lifespan: A systematic review and meta-analysis

To systematically review and analyze the effects of resistance-based exercise programs on body composition, regional adiposity, and body weight in individuals with overweight/obesity across the lifespan. Using PRISMA guidelines, randomized controlled trials were searched in nine electronic databases up to December 2020. Meta-analyses were performed using random-effects model. One-hundred sixteen articles describing 114 trials (n = 4184 participants) were included. Interventions involving resistance training and caloric restriction were the most effective for reducing body fat percentage (ES = -3.8%, 95% CI: -4.7 to -2.9%, p < 0.001) and whole-body fat mass (ES = -5.3 kg, 95% CI: -7.2 to -3.5 kg, p < 0.001) compared with groups without intervention. Significant results were also observed following combined resistance and aerobic exercise (ES = -2.3% and -1.4 kg, p < 0.001) and resistance training alone (ES = -1.6% and -1.0 kg, p < 0.001) compared with no training controls. Resistance training alone was the most effective for increasing lean mass compared with no training controls (ES = 0.8 kg, 95% CI: 0.6 to 1.0 kg, p < 0.001), whereas lean mass was maintained following interventions involving resistance training and caloric restriction (ES = ~ - 0.3 kg, p = 0.550-0.727). Results were consistently observed across age and sex groups (p = 0.001-0.011). Reductions in regional adiposity and body weight measures were also observed following combined resistance and aerobic exercise and programs including caloric restriction (p < 0.001). In conclusion, this study provides evidence that resistance-based exercise programs are effective and should be considered within any multicomponent therapy program when caloric restriction is utilized in individuals with overweight or obesity.

Neutral Effect of Increased Dairy Product Intake, as Part of a Lifestyle Modification Program, on Cardiometabolic Health in Adolescent Girls With Overweight/Obesity: A Secondary Analysis From a Randomized Controlled Trial

Background: The presence of obesity and some cardiometabolic disease risk factors in childhood and adolescence track into adulthood. Intake of dairy products has been shown to be inversely related to adiposity and cardiometabolic variables in youth. However, limited research has examined cardiometabolic disease risk factors following increased dairy product consumption as part of a lifestyle modification intervention in youth with overweight/obesity. This secondary analysis aimed to determine whether 12 weeks of increased dairy consumption, as part of a lifestyle modification program, affects cardiometabolic variables in adolescent females (range: 10-18 years) with overweight/obesity (BMI > 85th centile). Methods: Participants were randomized into two groups: higher dairy intake (RDa; four servings/day [to reflect previous Canada's Food Guide recommendations]; n = 23) or low dairy intake (LDa; 0-2 servings/day; n = 23). Both RDa and LDa participated in a 12-week, eucaloric, lifestyle modification intervention consisting of exercise training, and nutritional counseling. Adiposity (percent body fat [%BF]), dietary intake, and measures of cardiometabolic health were measured pre- and post-intervention. Results: There were no significant changes over time within groups or differences over time between groups for triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL), TC/HDL ratio, low-density lipoprotein cholesterol (LDL), glucose, insulin, homeostatic model assessment of insulin resistance, adiponectin, and tumor necrosis factor alpha (TNF-α) (main effects of time and interactions, p > 0.05). Leptin decreased over the 12-week lifestyle intervention in both groups (main effect of time, p = 0.02). After combining the groups (n = 46), significant correlations were found between change in %BF and change in some cardiometabolic variables (HDL [r = -0.40], TC/HDL ratio [r = 0.42], LDL [r = 0.36], and TNF-α [r = 0.35], p < 0.05). After controlling for change in dairy product intake, the correlations were unchanged. Conclusion: Our findings demonstrate that increased dairy product consumption, as part of a lifestyle modification, weight management intervention, had a neutral effect on cardiometabolic disease risk factors in adolescent females with overweight/obesity. Change in dairy product intake did not influence the relationships between change in adiposity and change in cardiometabolic variables. Future research designed to primarily assess the effect of increased dairy product consumption on cardiometabolic disease risk factors in this population is warranted. Clinical Trial Registration: Clinicaltrials.gov; NCT#02581813.

Role of exercise on insulin sensitivity and beta-cell function: is exercise sufficient for the prevention of youth-onset type 2 diabetes?

Parallel with the current pediatric obesity epidemic, the escalating rates of youthonset type 2 diabetes mellitus (T2DM) have become a major public health burden. Although lifestyle modification can be the first-line prevention for T2DM in youths, there is a lack of evidence to establish optimal specific exercise strategies for obese youths at high risk for T2DM. The purpose of this narrative review is to summarize the potential impact of exercise on 2 key pathophysiological risk factors for T2DM, insulin sensitivity and β-cell function, among obese youths. The studies cited are grouped by use of metabolic tests, i.e., direct and indirect measures of insulin sensitivity and β-cell function. In general, there are an increasing number of studies that demonstrate positive effects of aerobic exercise, resistance exercise, and the 2 combined on insulin sensitivity. However, a lack of evidence exists for the effect of any exercise modality on β-cell functional improvement. We also suggest a future direction for research into exercise medical prevention of youth-onset T2DM. These suggestions focus on the effects of exercise modalities on emerging biomarkers of T2DM risk.

Childhood Obesity as a Predictor of Coronary Artery Disease in Adults: A Literature Review

Obesity in children is becoming a worldwide epidemic that requires immediate attention. Despite all the efforts directed towards controlling this issue, its prevalence is increasing overtime both in developed and developing countries. With an increasing prevalence in the younger age groups, it is emerging as a public health crisis. A rise in body mass index (BMI) results in an increased risk of developing a variety of metabolic and cardiovascular diseases, particularly coronary artery disease (CAD). The early onset of the disease affects the peak productivity years in young individuals leading to disability at a later age. It makes it essential that we understand the contributory factors towards the development of obesity as a risk factor for CAD and develop strategies that hinder the progression towards adverse outcomes. There is an urgent need to screen these children at a younger age and educate them to change their lifestyle to decrease the BMI within the normal range to promote cardiovascular health. It requires a multidisciplinary approach involving dietary, physical, and behavioral-centered strategies. Failure to control this epidemic timely may cause widespread consequences for the quality of life and longevity. 

Exercise Dose and Weight Loss in Adolescents with Overweight-Obesity: A Meta-Regression

BACKGROUND

A recent meta-analysis reported that exercise interventions are effective for promoting weight loss in adolescents with overweight-obesity. However, the meta-analysis did not investigate whether there is an optimal exercise dose for promoting weight loss in overweight and obese adolescents. A common method of expressing exercise dose is the calculation of metabolic equivalents (METs), expressed as MET-h/week.

OBJECTIVES

The objective of this study was to determine the association between exercise dose (MET-h/week) and weight loss [body weight, body mass index (BMI)] in adolescents with overweight-obesity.

DATA SOURCES

Trials included in the original meta-analysis were extracted, and a subsequent search to identify studies published between May 2015 and May 2018 was conducted. The search included electronic databases (PubMed, Web of Science SPORTDiscus, Google Scholar) and the reference lists of eligible articles and relevant reviews.

STUDY SELECTION

The inclusion criteria were as follows: (i) randomized controlled trial; (ii) structured exercise intervention, alone or combined with other intervention components; (iii) control group received no structured exercise or behavioral modification designed to increase physical activity; (iv) participants overweight or obese (BMI ≥ 85th percentile); and (v) participants aged between 10 and 19 years.

APPRAISAL AND SYNTHESIS METHODS

Fifteen trials were extracted from the original meta-analysis. The current search identified an additional five trials (three articles). Data from 20 trials (16 articles) involving 1091 participants (54% female, 17% not reported) were included in the analysis. Effect sizes were reported as mean difference, and random effects meta-regression quantified the association between exercise dose and weight loss. Study quality was assessed using a modified Jadad's scale.

RESULTS

Total body weight change (decrease) ranged from - 2.7 to 19.3 (median 2.5) kg, and BMI change (decrease) ranged from - 1.6 to 6.3 (median 0.9) kg/m². MET-h/week ranged from 5.4 to 36.0 (median 6.0). Each MET-h/week was associated with a 0.13 kg/m² (95% confidence interval [CI] 0.08-0.19) and 0.33 kg (95% CI 0.08-0.59) decrease in BMI and body weight, respectively.

LIMITATIONS

The prescribed exercise dose for the majority of trials was low. As such, we were unable to discern whether there was an optimal exercise dose for weight loss (i.e., if the association between dose and weight loss was non-linear). Additionally, most trials had small sample sizes (median n = 34) and 17 trials had methodological limitations.

CONCLUSIONS

Each MET-h/week was associated with a 0.13 kg/m² and 0.33 kg decrease in BMI and body weight, respectively. While this relationship appears to be linear, i.e., no optimal exercise dose, it should be emphasized that the exercise prescription dose for the majority of trials was low. Subsequent trials, with greater exercise dosage, are required to determine whether there is an 'optimal' dose for promoting weight loss in adolescents with overweight-obesity. However, the current findings lend support to the use of exercise prescription for promoting weight loss and improving health outcomes in this population.

Characterising a Weight Loss Intervention in Obese Asthmatic Children

The prevalence of obesity in asthmatic children is high and is associated with worse clinical outcomes. We have previously reported that weight loss leads to improvements in lung function and asthma control in obese asthmatic children. The objectives of this secondary analysis were to examine: (1) changes in diet quality and (2) associations between the baseline subject characteristics and the degree of weight loss following the intervention. Twenty-eight obese asthmatic children, aged 8–17 years, completed a 10-week diet-induced weight loss intervention. Dietary intake, nutritional biomarkers, anthropometry, lung function, asthma control, and clinical outcomes were analysed before and after the intervention. Following the intervention, the body mass index (BMI) z-score decreased (Δ = 0.18 ± 0.04; p < 0.001), %energy from protein increased (Δ = 4.3 ± 0.9%; p = 0.002), and sugar intake decreased (Δ = 23.2 ± 9.3 g; p= 0.025). Baseline lung function and physical activity level were inversely associated with Δ% fat mass. The ΔBMI z-score was negatively associated with physical activity duration at baseline. Dietary intervention is effective in achieving acute weight loss in obese asthmatic children, with significant improvements in diet quality and body composition. Lower lung function and physical engagement at baseline were associated with lesser weight loss, highlighting that subjects with these attributes may require greater support to achieve weight loss goals.

Effects of a 30-week combined training program in normoxia and in hypoxia on exercise performance and health-related parameters in obese adolescents: a pilot study

BACKGROUND

A light but regular combined training program is sufficient to improve health in obese adolescents. Hypoxia is known to potentiate the effects of a high intensity period of combined training on exercise performance and glucose metabolism in this population. Here, we tested the effects of a less intensive hypoxic combined training program on exercise performance and health-related markers in obese adolescents.

METHODS

Fourteen adolescents volunteered to participate to a 30-week combined training protocol whether in normoxia (FiO2 21%, NE, N.=7) or in hypoxia (FiO2 15%, HE, N.=7). Once a week, adolescents exercised for 50-60min including 12min on a cycloergometer and strength training of the abdominal, quadriceps and biceps muscles.

RESULTS

Combined training reduced body mass (NE: -12%; HE: -8%), mainly due to a loss in fat mass (NE: -26%; HE: -15%), similarly in both the hypoxic and normoxic groups. After training, maximal O2 consumption (VO2max) (NE: +30%; HE: +25%,), maximal aerobic power (MAP) (NE: +20%; HE: +36%), work capacity and one-repetition maximum (1RM) for the quadriceps (NE: +26%; HE: +12%), abdominal (NE: +48%; HE: +36%) and biceps muscles (NE: +26%; HE: +16%) were increased similarly in both groups but insulin sensitivity markers were not modified.

CONCLUSIONS

Except for insulin sensitivity, 1h a week of combined training for 30 weeks improved morphological and health-related markers as well as exercise performance in obese adolescents in both normoxic and hypoxic conditions. This is of particular importance for motivating those adolescents, who often are reluctant to exercise. Even a low dose of exercise per week can induce positive health outcomes.

Understanding low adherence to an exercise program for adolescents with obesity: the HEARTY trial

INTRODUCTION

Despite efforts to improve adherence to physical activity interventions in youth with obesity, low adherence and attrition remain areas of great concern.

OBJECTIVE

The study was designed to determine which physiological and/or psychological factors predicted low adherence in adolescents with obesity enrolled in a 6-month exercise intervention study aimed to improve body composition.

METHODS

Three hundred four adolescents with obesity aged 14-18 years who volunteered for the HEARTY (Healthy Eating Aerobic and Resistance Training in Youth) randomized controlled trial completed physiological (body mass index, waist circumference, per cent body fat, resting metabolic rate and aerobic fitness) and psychological (body image, mood, self-esteem and self-efficacy) measures.

RESULTS

One hundred forty-one out of 228 (62%) randomized to exercise groups had low adherence (completed <70% of the prescribed four exercise sessions per week) to the intervention protocol. Logistic regression revealed that there were no baseline demographic or physiological variables that predicted low adherence in the participants. Appearance concern (a subscale of body image) (odds ratio [OR] 1.46, 95% confidence interval [CI]: 1.01, 2.1, P = 0.04), depressive mood (OR 1.12, 95% CI: 1.01, 1.23, P = 0.03) and confused mood (OR 1.16, 95% CI: 1.05, 1.27, P = 0.003) (two subscales of mood) were significant predictors of low adherence.

CONCLUSIONS

Adolescents with obesity who had higher appearance concerns and depressive and confused moods were less likely to adhere to exercise. Body image and mood should be screened to identify adolescents who may be at high risk of poor adherence and who may need concurrent or treatment support to address these psychological issues to derive maximal health benefits from an exercise programme.

What Is the Role of Resistance Exercise in Improving the Cardiometabolic Health of Adolescents with Obesity?

Traditionally, individuals with obesity have been encouraged to participate in aerobic exercise for long-term weight management and improved obesity-related health outcomes. Recently, resistance exercise has become a popular mode of exercise among youth with obesity. However, to date, the literature is mixed as to whether resistance exercise training alone improves body weight, fat free mass, body composition, cardiovascular risk factors, or atherogenic lipoprotein profiles. The limited research in this area suggests potential sex differences in response to resistance training in youth. The literature is more consistent in demonstrating improvements in muscular fitness and insulin resistance independent of caloric restriction and weight loss. Although major health organizations recommend combining aerobic and resistance training, little research has examined the effects of their combination versus their individual effects, thus it is unclear whether their combination is associated with benefits that extend beyond those of either exercise modality alone. The purpose of this review is to examine the effects of resistance exercise on body composition and the health risk factors associated with cardiovascular disease and type 2 diabetes in youth with obesity.

The effects of six-week resistance, aerobic and combined exercises on the pro-inflammatory and anti-inflammatory markers in overweight patients with moderate haemophilia A: A randomized controlled trial

INTRODUCTION

Overweight increases the secretion of pro-inflammatory cytokines and serves as a major risk factor for arthropathy and cardiovascular diseases (CVD). This condition is becoming increasingly prevalent among patients with haemophilia (PWH). Different forms of exercise training could favourably modify weight-related complications, cardiovascular risk factors and the inflammation.

AIM

To investigate the effects of resistance, aerobic and combined exercises on the pro-inflammatory and anti-inflammatory markers in overweight patients with moderate haemophilia A.

METHODS

Forty-eight patients with moderate haemophilia A, aged 35-55 years, and body mass index (BMI) of 25-30 kg/m² were randomly assigned to resistance training (RT, n = 12), aerobic (AT, n = 12), combined training (CT, n = 12) and control (n = 12) groups. The patients participated in 45-minutes exercise sessions three times a week for 6 weeks. Waist circumference (WC), waist-to-hip ratio (WHR), fat mass, fat-free mass, interleukin-10 (IL-10), adiponectin, tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6) and high sensitive C-reactive protein (hs-CRP) were measured before and after the 6 weeks of training.

RESULTS

There was significant decrease in WC, WHR, BMI and weight in the AT, RT and CT groups as compared to the control group. Total HJHS scores decreased in the AT, RT, CT groups compared to the control groups (P ≤ 0.001). The decrease in hs-CRP, IL-6 and TNF-α in the CT group was significant compared to the control group (P ≤ 0.02). The increase in IL-10 and adiponectin was not significant in the RT, AT and CT groups compared to the control group.

CONCLUSION

CT was the most effective training mode for decreasing the pro-inflammatory cytokines and increasing anti-inflammatory markers in overweight patients with haemophilia A.

Type 2 Diabetes in Latino Youth: A Clinical Update and Current Challenges

Latino youth have the highest prevalence of overweight and obesity among all ethnic groups and are disproportionally affected by pre diabetes and type 2 diabetes (T2DM). Interventions that effectively reduce the risk of pre diabetes and T2DM in this population are urgently needed. Studies have shown that without any change, 50% of Latino children and adolescents will develop T2DM. This has important public health implications. Few pharmacologic options are approved for use in the pediatric population. The largest clinical trial to date did include a significant sample of Latinos, however the intervention used metformin or rosiglitazone in addition to lifestyle management and did not show meaningful weight loss, with around half of the participants meeting criteria for treatment failure. On the other hand, a smaller trial on surgical treatment of adolescents with severe obesity and T2DM resulted in superior glycemic control, reduced weight, and improvement of other co-morbidities of T2DM in youth. Lastly, culturally tailored programs that focus on building healthy communities appear to be a promising intervention to reduce diabetes risk in Latino youth. This review provides an update on the clinical aspects of T2DM in Latino youth and focuses on management and prevention strategies.

Hypoxic Training Improves Normoxic Glucose Tolerance in Adolescents with Obesity

PURPOSE

This study aimed to test whether environmental hypoxia could potentiate the effects of exercise training on glucose metabolism and insulin sensitivity.

METHODS

Fourteen adolescents with obesity were assigned to 6 wk of exercise training either in normoxic or in hypoxic conditions (FiO2 15%). Adolescents trained three times per week for 50-60 min, including endurance and resistance exercises. Oral glucose tolerance test, blood and morphological analyses, and physical performance tests were performed before and after the training period.

RESULTS

After training, hypoxia, but not normoxia, decreased the area under the curve of plasma insulin (-49%; P = 0.001) and glucose levels (-14%; P = 0.005) during oral glucose tolerance test. Decreased plasma triglycerides levels (P = 0.03) and increased maximal aerobic power (P = 0.002), work capacity at 160 bpm (P = 0.002), and carbohydrate consumption during exercise (P = 0.03) were measured only in the hypoxic group.

CONCLUSIONS

Hypoxic exercise training was particularly efficient at improving glucose tolerance and insulin response to a glucose challenge in adolescents with obesity. These results suggest that exercise training in hypoxia could be an interesting strategy against insulin resistance and type 2 diabetes development in adolescents with obesity.

Efficacy of Exercise Intervention for Weight Loss in Overweight and Obese Adolescents: Meta-Analysis and Implications

BACKGROUND

The global rise in obesity prevalence among children and adolescents has been linked to modifiable lifestyle factors, including lack of physical activity. However, no known meta-analysis has been conducted on the effects of exercise intervention on body composition and cardiometabolic risk factors in overweight and obese adolescents.

OBJECTIVES

The aim of this study was to (1) estimate whether exercise intervention meaningfully improves body composition and cardiometabolic risk factors in overweight and obese adolescents; and (2) discuss the implications of the findings in terms of primary healthcare provision and public health policy, using New Zealand as an exemplar context.

DATA SOURCES

Electronic databases (PubMed, Web of Science, SPORTDiscus, Google Scholar) from inception to May 2015. The reference lists of eligible articles and relevant reviews were also checked.

STUDY SELECTION

Inclusion criteria were (1) randomized controlled trial; (2) structured exercise intervention, alone or combined with any other kind of intervention; (3) control group received no structured exercise or behavioural modification designed to increase physical activity; (4) participants overweight or obese (body mass index [BMI] ≥85th percentile); and (5) participants aged between 10 and 19 years.

APPRAISAL AND SYNTHESIS METHODS

Initially, 1667 articles were identified. After evaluation of study characteristics, quality and validity, data from 13 articles (15 trials) involving 556 participants (176 male, 193 female, 187 unknown) were extracted for meta-analysis. Meta-analyses were completed on five body composition parameters and ten cardiometabolic parameters. Effect sizes (ESs) were calculated as mean differences, as well as standardized mean differences in order to determine effect magnitude.

RESULTS

Exercise intervention reduced BMI (mean 2.0 kg/m², 95 % CI 1.5-2.5; ES moderate), body weight (mean 3.7 kg, 95 % CI 1.7-5.8; ES small), body fat percentage (3.1 %, 95 % CI 2.2-4.1; ES small), waist circumference (3.0 cm, 95 % CI 1.3-4.8; ES small), but the increase (improvement) in lean mass was trivial (mean 1.6 kg, 95 % CI 0.5-2.6). The response to an oral glucose tolerance test following exercise intervention was for a decrease in the area under the curve for insulin (mean 162 μU/μl, 95 % CI 93-231; ES large) and blood glucose (mean 39 mg/dl, 95 % CI 9.4-69; ES moderate). Improvements in the homeostatic model assessment were also noted (mean 1.0, 95 % CI 0.7-1.4; ES moderate) and systolic blood pressure (mean 7.1 mmHg, 95 % CI 3.5-10.7; ES moderate). The effects of exercise on total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, fasting insulin and fasting blood glucose were inconclusive.

LIMITATIONS

Most of the included trials were short term (6-36 weeks) and 13 had methodological limitations. Additionally, the meta-analyses for some of the secondary outcomes had a small number of participants or substantial statistical heterogeneity.

CONCLUSIONS

The current evidence suggests that exercise intervention in overweight and obese adolescents improves body composition, particularly by lowering body fat. The limited available evidence further indicates that exercise intervention may improve some cardiometabolic risk factors.

A single exercise session increases insulin sensitivity in normal weight and overweight/obese adolescents

We measured the effect of an aerobic exercise session on postprandial glucose control in adolescents with habitually low-physical activity. The goal was to determine if the acute or residual response of exercise was altered in people who are overweight/obese (OW/Ob). Eleven normal weight, body mass index (NW, BMI = 48 ± 13 percentile) and 12 OW/Ob (BMI = 91 ± 5 percentile) participants completed 3 trials. In the no exercise (No Ex) trial, participants rested quietly before and after consuming a test meal. In the other 2 trials, a 45-minute aerobic exercise session was performed either 17-hour (Prior Day Ex) or 40 minutes (Same Day Ex) before the test meal. On all trials, the OW/Ob group had higher fasting glucose (~6%) and insulin (~66%), and lower insulin sensitivity (~9%) than the NW group. The Same Day Ex and Prior Day Ex trials resulted in reduced area under the curve for glucose (6% on both trials, P < .01) and insulin (15% and 13%, respectively, P < .03), and increased insulin sensitivity (8% and 6%, respectively, P < .01). The magnitudes of those effects did not differ between the NW and OW/Ob groups. Plasma fatty acids declined and carbohydrate oxidation increased after the meal, but did not differ among trials or groups. The results demonstrate that moderate intensity aerobic exercise increases insulin sensitivity in NW and OW/Ob adolescents and that the beneficial effects of exercise last up to 17 hours. The acute impact of exercise on metabolic health in adolescents is not impaired in overweight/obese participants.

A Twelve-Week Lifestyle Program to Improve Cardiometabolic, Behavioral, and Psychological Health in Hispanic Children and Adolescents

OBJECTIVES

To examine the effectiveness of a 12-week lifestyle program on cardiometabolic, behavioral, and psychological outcomes among overweight Hispanic children and adolescents.

DESIGN

A case series study with pre- and post-test analyses. Subjects/Settings/Location: A convenience sample of high-risk pediatric primary care patients (n = 22; 6 girls, 16 boys; M age = 11.73 ± 1.39 years) and their guardians in the Southeast United States.

INTERVENTION

Twice per week 60 min (total of 24 h) of moderate-to-vigorous intensity boxing exercise training, 12 h of nutrition education for guardians, and a 30-min pediatrician appointment.

OUTCOME MEASURES

Cardiometabolic (height [m], weight [kg], waist circumference [cm], body-mass index [BMI], BMI-z, BMI%, cholesterol [mg/dL], triglycerides [mg/dL], glucose [mg/dL], and low-density lipoprotein and high-density lipoprotein cholesterol [mg/dL]), behavioral (objective free time physical activity [PA] and sedentary time [min/day]), and psychological (self-determined exercise motivation) outcomes were measured/calculated, and paired-samples t-tests were conducted.

RESULTS

A significant reduction was observed in waist circumference t(17) = -2.57, p = 0.020, d = 0.64; BMI% t(15) = -2.53, p = 0.023, d = 0.20; fasting glucose t(15) = -6.43, p < 0.001, d = 1.67; and amotivation (-) t(17) = -2.29, p = 0.036, d = 0.64; whereas a significant increase was identified in moderate t(10) = 4.01, p = 0.002, d = 1.23 and vigorous t(10) = 3.41, p = 0.007, d = 1.07 intensity PA; intrinsic motivation t(17) = 2.71, p = 0.015, d = 0.38; and introjected regulation t(17) = 2.74, p = 0.014, d = 0.64.

CONCLUSIONS

A 12-week lifestyle program can be effective in improving selected health markers among overweight Hispanic children and adolescents. The positive changes in fasting glucose, BMI, and waist suggest that the participants are currently at lower risk for both type 2 diabetes and cardiovascular disease as a result of the Confidence, Ownership, Responsibility, and Exercise program.

Prevention of Type 2 Diabetes in U.S. Hispanic Youth: A Systematic Review of Lifestyle Interventions

CONTEXT

Prevalence of type 2 diabetes mellitus (T2DM) in youth has increased rapidly in recent decades along with rises in childhood obesity. Disparities in risk and prevalence of T2DM are evident in Hispanic youth when compared with non-Hispanic whites. Targeted diabetes prevention programs have been recommended to reduce risk prior to adulthood in this population. This systematic review explores the effectiveness of lifestyle-based diabetes prevention interventions for Hispanic youth.

EVIDENCE ACQUISITION

PubMed, PsycINFO, Web of Science, and CENTRAL were searched from database inception to March 1, 2017, for studies that evaluated lifestyle-focused prevention trials targeting U.S. Hispanic youth under age 18 years. Fifteen publications met criteria for inclusion.

EVIDENCE SYNTHESIS

Of the 15 studies, 11 were RCTs; four were uncontrolled. Interventions were heterogeneous in intensity, content, and setting. Duration of most trials was 12-16 weeks. Mean age of participants ranged from 9.8 to 15.8 years, sample sizes were generally small, and the majority of participants were overweight (BMI ≥85th percentile). Three studies reported statistically significant reductions in mean BMI, four in BMI z-score, and six in fasting glucose/insulin. Study quality was moderate to high. Effect sizes were generally small to medium.

CONCLUSIONS

Evidence for the impact of lifestyle-based diabetes prevention interventions targeting U.S. Hispanic youth remains limited. Few interventions demonstrated success in reducing BMI and glucose regulation and follow-up times were brief. More studies are needed that recruit larger samples sizes, extend follow-up times, explore innovative delivery modalities, and examine effectiveness across sex and age.

Resistance Training Effects on Metabolic Function Among Youth: A Systematic Review

PURPOSE

This systematic review evaluates the relationship between resistance training and metabolic function in youth.

METHODS

PubMed, Embase, Cochrane Library, Web of Science, CINAHL, and ClinicalTrials. gov were searched for articles that (1): studied children (2); included resistance training (3); were randomized interventions; and (4) reported markers of metabolic function. The selected studies were analyzed using the Cochrane Risk-of-Bias Tool.

RESULTS

Thirteen articles met inclusion criteria. Mean age ranged from 12.2 to 16.9 years, but most were limited to high school (n = 11) and overweight/obese (n = 12). Sample sizes (n = 22-304), session duration (40-60min), and intervention length (8-52 wks) varied. Exercise frequency was typically 2-3 d/wk. Resistance training was metabolically beneficial compared with control or resistance plus aerobic training in 5 studies overall and 3 out of the 4 studies with the fewest threats to bias (p ≤ .05); each was accompanied by beneficial changes in body composition, but only one study adjusted for change in body composition.

CONCLUSIONS

Limited evidence suggests that resistance training may positively affect metabolic parameters in youth. Well-controlled resistance training interventions of varying doses are needed to definitively determine whether resistance training can mitigate metabolic dysfunction in youth and whether training benefits on metabolic parameters are independent of body composition changes.

Effectiveness of interventions on physical activity in overweight or obese children: a systematic review and meta-analysis including studies with objectively measured outcomes

There is no consensus on interventions to be recommended in order to promote physical activity among overweight or obese children. The objective of this review was to assess the effects on objectively measured physical activity, of interventions promoting physical activity among overweight or obese children or adolescents, compared to no intervention or to interventions without a physical activity component. Publications up to December 2015 were located through electronic searches for randomized controlled trials resulting in inclusion of 33 studies. Standardized mean differences from baseline to post-intervention and to long-term follow-up were determined for intervention and control groups and meta-analysed using random effects models. The meta-analysis showed that interventions had no effect on total physical activity of overweight and obese children, neither directly post-intervention (-0.02 [-0.15, 0.11]) nor at long-term follow-up (0.07 [-0.27, 0.40]). Separate analyses by typology of intervention (with or without physical fitness, behavioural or environmental components) showed similar results (no effect). In conclusion, there is no evidence that currently available interventions are able to increase physical activity among overweight or obese children. This questions the contribution of physical activity to the treatment of overweight and obesity in children in the studied interventions and calls for other treatment strategies.

Concurrent aerobic plus resistance exercise versus aerobic exercise alone to improve health outcomes in paediatric obesity: a systematic review and meta-analysis

OBJECTIVE

To determine if the combination of aerobic and resistance exercise is superior to aerobic exercise alone for the health of obese children and adolescents.

DESIGN

Systematic review with meta-analysis.

DATA SOURCES

Computerised search of 3 databases (MEDLINE, EMBASE, and Cochrane Controlled Trials Registry).

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies that compared the effect of supervised concurrent exercise versus aerobic exercise interventions, with anthropometric and metabolic outcomes in paediatric obesity (6-18 years old). The mean differences (MD) of the parameters from preintervention to postintervention between groups were pooled using a random-effects model.

RESULTS

12 trials with 555 youths were included in the meta-analysis. Compared with aerobic exercise alone, concurrent exercise resulted in greater reductions in body mass (MD=-2.28 kg), fat mass (MD=-3.49%; and MD=-4.34 kg) and low-density lipoprotein cholesterol (MD=-10.20 mg/dL); as well as greater increases in lean body mass (MD=2.20 kg) and adiponectin level (MD=2.59 μg/mL). Differences were larger for longer term programmes (>24 weeks).

SUMMARY

Concurrent aerobic plus resistance exercise improves body composition, metabolic profiles, and inflammatory state in the obese paediatric population.

TRIAL REGISTRATION NUMBER

CRD42016039807.

Effects of aerobic, resistance, and combined exercise training on insulin resistance markers in overweight or obese children and adolescents: A systematic review and meta-analysis

OBJECTIVE

To assess the associations of aerobic, resistance, and combined exercise with changes in insulin resistance, fasting glucose, and fasting insulin in children and adolescents who are overweight or obese.

DATA SEARCHES

MEDLINE via Pubmed, Cochrane-CENTRAL, SPORTDiscus, and LILACS.

STUDY SELECTION

Randomized clinical trials of at least six weeks of duration that evaluated the ability of exercise training to lower at least one of the following outcomes: insulin resistance-HOMA, fasting glucose, and fasting insulin in children and/or adolescents classified as obese or overweight.

DATA EXTRACTION AND ANALYSIS

Two independent reviewers extracted data and assessed the quality of the included studies. Differences (exercise training group minus control group) in the outcomes evaluated were analyzed using a random effects model.

RESULTS

Of 1853 articles retrieved, 17 studies were included. The meta-analysis showed that physical training in general was not associated with a reduction in fasting glucose levels compared to the control, but it was associated with reductions in fasting insulin levels (-3.37μU/ml; CI 95%, -5.16μU/ml to -1.57μU/ml; I², 54%, p=0.003) and HOMA (-0.61; CI 95%, -1.19 to -0.02; I², 49%, p=0.040). In addition, each modality (aerobic, resistance, and combined) was compared to the control group. Aerobic exercise was associated with declines in fasting insulin levels (-4.52μU/ml; CI 95%, -7.40 to -1.65; I², 65%, p=0.002) and in HOMA (-1.33; 95% confidence interval, -2.47 to -0.18; I², 73%, p=0.005).

CONCLUSIONS

Exercise training, especially aerobic training, is associated with the reduction of fasting insulin levels and HOMA in children and adolescents with obesity and overweight, and may prevent metabolic syndrome and type 2 diabetes.

Effects of two diet techniques and delivery mode on weight loss, metabolic profile and food intake of obese adolescents: a fixed diet plan and a calorie-counting diet

The aim of this study is to compare the weight loss of obese adolescents on two different low-calorie diets: fixed diet plan and calorie-counting diet. This is a randomized clinical study with 66 obese adolescents (body mass index Z score (ZBMI)>+3, 13.7±0.7 years, 60.6% male) with anthropometric, food intake, physical activity, laboratory, body composition and stage of pubertal development data evaluated. There was a reduction in the ZBMI in both groups (P<0.0001), without significant difference between them (P=0.87). There was a significant reduction in insulin, and homeostasis model assessment insulin resistance (HOMA-IR), with no difference between groups. A reduction in total energy intake of the groups was found, with an increase in the proportion of protein and reduction in carbohydrates. In this cohort of severely obese adolescents, fixed diet plan and calorie-counting diet led to a similar reduction of ZBMI, metabolic markers and total energy intake.

An Integrative Analysis of the Effect of Lifestyle and Pharmacological Interventions on Glucose Metabolism in the Prevention and Treatment of Youth-Onset Type 2 Diabetes

Preventing and managing youth-onset type 2 diabetes are a major challenge. This paper reviews the evidence of lifestyle and drug therapies in improving glucose, insulin, and insulin sensitivity. Forty-four interventions were analyzed, of which 11 were drug (mainly metformin) interventions combined with lifestyle while the remainder used lifestyle strategies only. Fewer than a dozen out of 44 interventions reported significant improvements in glucose-related outcomes. Metformin in addition to lifestyle therapy did not necessarily enhance intervention effects. The overall lack of findings can be partially attributed to the heterogeneity of study populations, the lack of intervention intensity, under-powered study design, and the challenging lives of at-risk populations. New treatment options in both drugs and lifestyle strategies are direly needed.

Effects of aerobic training, resistance training, or both on cardiorespiratory and musculoskeletal fitness in adolescents with obesity: the HEARTY trial

The purpose of this study was to examine the effects of aerobic, resistance, and combined exercise training on cardiorespiratory and musculoskeletal fitness in postpubertal adolescents with obesity. After a 4-week supervised moderate-intensity exercise run-in, 304 adolescents aged 14-18 years with body mass index ≥85th percentile were randomized to 4 groups for 22 weeks of aerobic training, resistance training, combined training, or a nonexercising control. All participants received dietary counselling with a maximum daily energy deficit of 250 kcal. Cardiorespiratory fitness (peak oxygen consumption) was measured by indirect calorimetry using a graded treadmill exercise test. Musculoskeletal fitness was measured using the 2003 Canadian Physical Activity Fitness and Lifestyle Appraisal tests (hand grip, push-ups, partial curl-ups, sit and reach, and vertical jump). Muscular strength was assessed using an 8-repetition maximum test on the bench press, seated row, and leg press machines. A greater increase in peak oxygen consumption in the aerobic exercise group (30.6 ± 0.6 to 33.4 ± 0.7 mLO2/kg/min) was measured relative to the control group (30.6 ± 0.5 to 30.9 ± 0.7 mLO2/kg/min) (p = 0.002). Similarly, the number of partial curl-ups increased in the aerobic group (19 ± 1 to 23 ± 1) while no differences were measured in the control group (19 ± 1 to 20 ± 1) (p = 0.015). Increases in muscular strength and number of push-ups were greatest in the resistance group versus the control and combined groups versus the aerobic group (p < 0.05). In conclusion, aerobic training had the strongest effect on cardiorespiratory fitness, while resistance and combined training improved both muscular strength and endurance more than control and aerobic training alone, respectively, in adolescents with obesity.

Health benefits of endurance training alone or combined with diet for obese patients over 60: a review

BACKGROUND

The prevalence of obesity is rapidly increasing in older patients and it is ubiquitous in many developed countries. Obesity is related to various negative health outcomes, making it a major public health target for intervention.

PURPOSE

The aim of this study was to explore and summarise the literature that addresses endurance training alone or combined with nutrition interventions to combat obesity in obese patients over age 60.

METHODS

We searched online electronic databases up to September 2014 for original observational and intervention studies published between 1995 and 2014 on the relationship between endurance training alone or combined with a diet in obese patients over 60 regarding health outcomes.

RESULTS

Twenty-six studies examined interventions aimed specifically at promoting endurance training alone or combined with diet for older obese patients over 60. These studies demonstrated a positive effect of this intervention on the primary prevention of cardiovascular disease, and a significant beneficial effect on the lipid profile. Improvement of body composition and insulin sensitivity, and a reduction in blood pressure were also well established.

CONCLUSIONS

Overall, this review demonstrates a positive effect of endurance training alone or combined with diet on health outcomes and metabolic benefits in older adults. Clinicians can now use this evidence to formulate actions to encourage the older obese to profit from the health benefits of endurance training and diet. This will not only help reduce the dramatic increase in the number of older obese but also help prevent sarcopenic obesity, which is a complex challenge for healthcare professionals.

Do Overweight Adolescents Adhere to Dietary Intervention Messages? Twelve-Month Detailed Dietary Outcomes from Curtin University's Activity, Food and Attitudes Program

Dietary components of adolescent obesity interventions are rarely evaluated with comprehensive reporting of dietary change. The objective was to assess dietary change in overweight adolescents, including adherence to dietary intervention. The dietary intervention was part of a multi-component intervention (CAFAP) targeting the physical activity, sedentary and healthy eating behaviors of overweight adolescents (n = 69). CAFAP was a staggered entry, within-subject, waitlist controlled clinical trial with 12 months of follow up. Diet was assessed using three-day food records and a brief eating behavior questionnaire. Changes in dietary outcomes were assessed using linear mixed models, adjusted for underreporting. Food record data suggested reduced adherence to dietary intervention messages over time following the intervention, despite conflicting information from the brief eating behavior questionnaire. During the intervention, energy intake was stable but favorable nutrient changes occurred. During the 12 month maintenance period; self-reported eating behaviors improved, energy intake remained stable but dietary fat and saturated fat intake gradually returned to baseline levels. Discrepancies between outcomes from brief dietary assessment methods and three-day food records show differences between perceived and actual intake, highlighting the need for detailed dietary reporting. Further, adherence to dietary intervention principles reduces over time, indicating a need for better maintenance support.

The impact of Curtin University's activity, food and attitudes program on physical activity, sedentary time and fruit, vegetable and junk food consumption among overweight and obese adolescents: a waitlist controlled trial

Background

To determine the effects of participation in Curtin University's Activity, Food and Attitudes Program (CAFAP), a community-based, family-centered behavioural intervention, on the physical activity, sedentary time, and healthy eating behaviours of overweight and obese adolescents.

Methods

In this waitlist controlled clinical trial in Western Australia, adolescents (n = 69, 71% female, mean age 14.1 (SD 1.6) years) and parents completed an 8-week intervention followed by 12 months of telephone and text message support. Assessments were completed at baseline, before beginning the intervention, immediately following the intervention, and at 3-, 6-, and 12- months follow-up. The primary outcomes were physical activity and sedentary time assessed by accelerometers and servings of fruit, vegetables and junk food assessed by 3-day food records.

Results

During the intensive 8-week intervention sedentary time decreased by −5.1 min/day/month (95% CI: −11.0, 0.8) which was significantly greater than the rate of change during the waitlist period (p = .014). Moderate physical activity increased by 1.8 min/day/month (95% CI: −0.04, 3.6) during the intervention period, which was significantly greater than the rate of change during the waitlist period (p = .041). Fruit consumption increased during the intervention period (monthly incidence rate ratio (IRR) 1.3, 95% CI: 1.10, 1.56) and junk food consumption decreased (monthly IRR 0.8, 95% CI: 0.74, 0.94) and these changes were different to those seen during the waitlist period (p = .004 and p = .020 respectively).

Conclusions

Participating in CAFAP appeared to have a positive influence on the physical activity, sedentary and healthy eating behaviours of overweight and obese adolescents and many of these changes were maintained for one year following the intensive intervention.

Trial Registration

Australia and New Zealand Clinical Trials Registry ACTRN12611001187932

Controlling childhood obesity: A systematic review on strategies and challenges

BACKGROUND

Childhood obesity is a global health problem with short- and long-term health consequences. This systematic review presents a summary of the experiences on different family-, school-, and clinic-based interventions.

MATERIALS AND METHODS

Electronic search was conducted in MEDLINE, PubMed, ISI Web of Science, and Scopus scientific databases. We included those studies conducted among obese individuals aged up to 18 years. Our search yielded 105 relevant papers, 70 of them were conducted as high quality clinical trials.

RESULTS

Our findings propose that school-based programs can have long-term effects in a large target group. This can be related to this fact that children spend a considerable part of their time in school, and adopt some parts of lifestyle there. They have remarkable consequences on health behaviors, but as there are some common limitations, their effects on anthropometric measures are not clear. Due to the crucial role of parents in development of children's behaviors, family-based interventions are reported to have successful effects in some aspects; but selection bias and high dropout rate can confound their results. Clinic-based interventions revealed favorable effects. They include dietary or other lifestyle changes like increasing physical activity or behavior therapy. It seems that a comprehensive intervention including diet and exercise are more practical. When they have different designs, results are controversial.

CONCLUSION

We suggest that among different types of interventional programs, a multidisciplinary approach in schools in which children's family are involved, can be the best and most sustainable approach for management of childhood obesity.

Effects of in utero conditions on adult feeding preferences

The fetal or early origins of adult disease hypothesis states that environmental factors, particularly nutrition, act in early life to program the risks for chronic diseases in adult life. As eating habits can be linked to the development of several diseases including obesity, diabetes and cardiovascular disease, it could be proposed that persistent food preferences across the life-span in people who were exposed to an adverse fetal environment may partially explain their increased risk to develop metabolic disease later in life. In this paper, we grouped the clinical and experimental evidence demonstrating that the fetal environment may impact the individual's food preferences. In addition, we review the feeding preferences development and regulation (homeostatic and hedonic pathways, the role of taste/olfaction and the reward/pleasure), as well as propose mechanisms linking early life conditions to food preferences later in life. We review the evidence suggesting that in utero conditions are associated with the development of specific food preferences, which may be involved in the risk for later disease. This may have implications in terms of public health and primary prevention during early ages.

What is the effect of resistance training on the strength, body composition and psychosocial status of overweight and obese children and adolescents? A Systematic review and meta-analysis

BACKGROUND

Overweight and obese children and adolescents face many physical and psychosocial hardships. Resistance training is a modality of exercise which allows this at-risk group to excel and therefore has the potential to positively affect not only their physical but also psychosocial health.

OBJECTIVE

To systematically review and meta-analyse the peer-reviewed literature to determine the effect of resistance training on the strength, body composition and psychosocial status of overweight and/or obese children and/or adolescents.

DATA SOURCES

Relevant databases (MEDLINE, Embase, Scopus, Web of Science, SPORTDiscus, CINAHL, PsycINFO, Cochrane library, ProQuest) were searched up to and including 30 January 2013.

STUDY SELECTION

Included studies (n = 40, from the 2,247 identified) were randomised controlled trials (RCTs), non-randomised controlled trials (NRCTs) and uncontrolled trials (UCTs) which had run an exercise intervention, with a resistance training component, for overweight and/or obese children and/or adolescents, and which had examined the effect of resistance training on either strength, body composition or psychosocial outcomes.

STUDY APPRAISAL AND SYNTHESIS METHODS

Studies were initially critically appraised for risk of bias by the lead author, following which both co-authors critically appraised five randomly selected studies to assess reliability.

RESULTS

Randomised controlled trials and NRCTs were analysed separately from UCTs. To determine the overall intervention effect for each outcome variable for each study design group, standardised mean differences were calculated with each individual study/data set weighted by the inverse of the pooled variance. The overall intervention effect reported for RCTs and NRCTs was relative to the control group whereas the effect reported for UCTs shows an overall post-intervention effect. Subgroup analyses, which determined whether the overall intervention effect was influenced by intervention type, training volume, age, sex, risk of bias or study design (for RCT/NRCT group only), were run using the same summary measure. Typically, resistance training had very small to small effects on body composition and moderate to large effects on strength in favour of the intervention. However, the magnitude and direction of the effect of resistance training on psychological outcomes are still unclear given the limited number of studies which looked at psychosocial outcomes and the inconclusive results shown by this review. Uncontrolled trials typically showed larger intervention effects than RCTs and NRCTs; however, these results may be greatly influenced by maturational changes rather than the intervention itself.

LIMITATIONS

The included studies employed a number of different exercise intervention types (e.g. resistance training, resistance plus aerobic training etc.) that ranged from 6 to 52 weeks in duration. Studies also employed a number of different methodologies to assess similar outcome measures (e.g. dual energy X-ray absorptiometry versus skinfolds to assess body composition; one-repetition maximum testing versus hand grip strength to assess strength). However, by completing subgroup analyses and using a standardised summary measure these limitations have been accounted for.

CONCLUSION

While the effect of resistance training on the body composition and strength of overweight and obese children and adolescents is clear, given the paucity of conclusive data more studies are needed to fully understand the effect of resistance training on the psychosocial status of this population.

Barriers and enablers for participation in healthy lifestyle programs by adolescents who are overweight: a qualitative study of the opinions of adolescents, their parents and community stakeholders

BACKGROUND

Overweight or obesity during adolescence affects almost 25% of Australian youth, yet limited research exists regarding recruitment and engagement of adolescents in weight-management or healthy lifestyle interventions, or best-practice for encouraging long-term healthy behaviour change. A sound understanding of community perceptions, including views from adolescents, parents and community stakeholders, regarding barriers and enablers to entering and engaging meaningfully in an intervention is critical to improve the design of such programs.

METHODS

This paper reports findings from focus groups and semi-structured interviews conducted with adolescents (n?=?44), parents (n?=?12) and community stakeholders (n?=?39) in Western Australia. Three major topics were discussed to inform the design of more feasible and effective interventions: recruitment, retention in the program and maintenance of healthy change. Data were analysed using content and thematic analyses.

RESULTS

Data were categorised into barriers and enablers across the three main topics. For recruitment, identified barriers included: the stigma associated with overweight, difficulty defining overweight, a lack of current health services and broader social barriers. The enablers for recruitment included: strategic marketing, a positive approach and subsidising program costs. For retention, identified barriers included: location, timing, high level of commitment needed and social barriers. Enablers for retention included: making it fun and enjoyable for adolescents, involving the family, having an on-line component, recruiting good staff and making it easy for parents to attend. For maintenance, identified barriers included: the high degree of difficulty in sustaining change and limited services to support change. Enablers for maintenance included: on-going follow up, focusing on positive change, utilisation of electronic media and transition back to community services.

CONCLUSIONS

This study highlights significant barriers for adolescents and parents to overcome to engage meaningfully with weight-management or healthy lifestyle programs. A number of enablers were identified to promote ongoing involvement with an intervention. This insight into specific contextual opinions from the local community can be used to inform the delivery of healthy lifestyle programs for overweight adolescents, with a focus on maximising acceptability and feasibility.

Exercise and insulin resistance in youth: a meta-analysis

BACKGROUND AND OBJECTIVES

The prevalence of obesity and diabetes is increasing among children, adolescents, and adults. Although estimates of the efficacy of exercise training on fasting insulin and insulin resistance have been provided, for adults similar estimates have not been provided for youth. This systematic review and meta-analysis provides a quantitative estimate of the effectiveness of exercise training on fasting insulin and insulin resistance in children and adolescents.

METHODS

Potential sources were limited to peer-reviewed articles published before June 25, 2013, and gathered from the PubMed, SPORTDiscus, Physical Education Index, and Web of Science online databases. Analysis was limited to randomized controlled trials by using combinations of the terms adolescent, child, pediatric, youth, exercise training, physical activity, diabetes, insulin, randomized trial, and randomized controlled trial. The authors assessed 546 sources, of which 4.4% (24 studies) were eligible for inclusion. Thirty-two effects were used to estimate the effect of exercise training on fasting insulin, with 15 effects measuring the effect on insulin resistance. Estimated effects were independently calculated by multiple authors, and conflicts were resolved before calculating the overall effect.

RESULTS

Based on the cumulative results from these studies, a small to moderate effect was found for exercise training on fasting insulin and improving insulin resistance in youth (Hedges' d effect size = 0.48 [95% confidence interval: 0.22-0.74], P < .001 and 0.31 [95% confidence interval: 0.06-0.56], P < .05, respectively).

CONCLUSIONS

These results support the use of exercise training in the prevention and treatment of type 2 diabetes.

Is Physical Fitness Associated with Health in Overweight and Obese Youth? A Systematic Review

A systematic review of literature was conducted to examine the association between changes in health-related fitness (e.g. aerobic capacity and muscular strength /endurance) and chronic disease risk factors in overweight and/or obese youth. Studies published from 2000-2010 were included if the physical activity intervention was a randomized controlled trial and reported changes in fitness and health outcomes by direction and significance (p< 0.05) of the effect. Aerobic capacity improved in 91% and muscular fitness improved in 82% of measures reported. Nearly all studies (32 of 33) reported improvement in at least one fitness test. Changes in outcomes related to adiposity, cardiovascular, musculoskeletal, metabolic, and mental/emotional health improved in 60%, 32%, 53%, 41%, and 33% of comparisons studied, respectively. In conclusion, overweight and obese youth can improve physical fitness across a variety of test measures. When fitness improves, beneficial health effects are observed in some, but not all chronic disease risk factors.

Decreased cardiotrophin-1 levels are associated with a lower risk of developing the metabolic syndrome in overweight/obese children after a weight loss program

OBJECTIVE

Cardiotrophin-1 (CT-1) shares some similarities with other cytokines, and participates in the control of energy metabolism. Higher circulating levels are observed in obese humans, but little information is gathered in weight loss (WL) programs. Therefore, we aimed to investigate the association of serum CT-1 levels with metabolic variables and the risk of developing metabolic syndrome (MetS) after a WL program in overweight/obese children.

SUBJECTS AND METHODS

Forty-four overweight/obese children (mean age 11.5 y; 50% males) undergoing a 10-week WL program were enrolled. Subjects were dichotomized at the median of Body Mass Index-Standard Deviation Score (BMI-SDS) change, as high and low responders after intervention.

RESULTS

CT-1 levels were significantly reduced (-48 fmol/mL, p=0.043) in the high responder group after the WL program. They had significantly lower body weight (-3.7 kg, p<0.001), body fat mass (-8%, p<0.001), BMI-SDS (-0.78, p<0.001) and waist circumference (-5.4 cm, p<0.001), and a significant improvement in lipid and glucose profiles (p<0.05). Interestingly, decreased CT-1 levels significantly predicted changes in total cholesterol (41%) and LDL-cholesterol (28%). Moreover, in our participants the lower the CT-1 levels, the higher the reduction in MetS risk components, after the 10-week intervention, (p-ANCOVA=0.040, p-trend=0.024).

CONCLUSION

We showed, for the first time, a reduction in serum CT-1 levels after a WL program and this decrease in CT-1 was strongly associated with a reduction in cholesterol levels and in MetS risk factors in overweight/obese children. Our findings may suggest that CT-1 could be an indirect marker for the diagnosis of MetS in this population.

Effects of exercise alone on insulin sensitivity and glucose tolerance in obese youth

As with the dramatic increases in childhood obesity over the past decades, the incidence of type 2 diabetes has increased among children and adolescents in the United States. Insulin resistance is a common feature of childhood obesity and increases the risk of type 2 diabetes, metabolic syndrome, and atherogenic lipoprotein profile in obese youth. Although cross-sectional studies report beneficial effects of physical activity or cardiorespiratory fitness on insulin sensitivity, the role of regular exercise alone (e.g., no calorie restriction) as a strategy to reduce the risk of type 2 diabetes is unclear in obese children and adolescents. In this mini review, we examined the independent effects of various exercise on glucose tolerance and insulin sensitivity in obese youth.

Body fat and fitness improvements in Hispanic and African American girls

OBJECTIVE

The design of effective obesity interventions to reduce adiposity and increase fitness in minority children is a public health priority. This study assessed the effectiveness of a summer intervention in lowering adiposity and increasing aerobic endurance in minority girls.

METHODS

99 Hispanic and African American girls and their mothers participated. During the intervention, girls attended daily exercise, nutrition education, and counseling sessions from 9:00 AM to 5:00 PM. Mothers attended 2-h weekly exercise, nutrition, and counseling sessions. Percent body fat, abdominal fat, and aerobic endurance (1-mile run/walk minutes) data were collected at pre- and post-intervention.

RESULTS

A repeated-measures analysis of variance was used to test differences in adiposity indicators and aerobic endurance. Findings indicated statistically significant reductions in percent body fat (p < .001), abdominal fat (p < .001), and 1-mile run/walk minutes (p < .001).

CONCLUSIONS

This study demonstrated the effectiveness of a summer intervention in reducing adiposity indicators and increasing aerobic endurance.

The quality of dietary intake methodology and reporting in child and adolescent obesity intervention trials: a systematic review

Assessing dietary intake is important in evaluating childhood obesity intervention effectiveness. The purpose of this review was to evaluate the dietary intake methods and reporting in intervention studies that included a dietary component to treat overweight or obese children. A systematic review of studies published in the English language, between 1985 and August 2010 in health databases. The search identified 2,295 papers, of which 335 were retrieved and 31 met the inclusion criteria. Twenty-three studies reported energy intake as an outcome measure, 20 reported macronutrient intakes and 10 studies reported food intake outcomes. The most common dietary method employed was the food diary (n = 13), followed by 24-h recall (n = 5), food frequency questionnaire (FFQ) (n = 4) and dietary questionnaire (n = 4). The quality of the dietary intake methods reporting was rated as 'poor' in 15 studies (52%) and only 3 were rated as 'excellent'. The reporting quality of FFQs tended to be higher than food diaries/recalls. Deficiencies in the quality of dietary intake methods reporting in child obesity studies were identified. Use of a dietary intake methods reporting checklist is recommended. This will enable the quality of dietary intake results to be evaluated, and an increased ability to replicate study methodology by other researchers.

Effectiveness of lifestyle interventions in child obesity: systematic review with meta-analysis

BACKGROUND AND OBJECTIVES

The effects of lifestyle interventions on cardio-metabolic outcomes in overweight children have not been reviewed systematically. The objective of the study was to examine the impact of lifestyle interventions incorporating a dietary component on both weight change and cardio-metabolic risks in overweight/obese children.

METHODS

English-language articles from 1975 to 2010, available from 7 databases, were used as data sources. Two independent reviewers assessed articles against the following eligibility criteria: randomized controlled trial, participants overweight/obese and ≤18 years, comparing lifestyle interventions to no treatment/wait-list control, usual care, or written education materials. Study quality was critically appraised by 2 reviewers using established criteria; Review Manager 5.1 was used for meta-analyses.

RESULTS

Of 38 eligible studies, 33 had complete data for meta-analysis on weight change; 15 reported serum lipids, fasting insulin, or blood pressure. Lifestyle interventions produced significant weight loss compared with no-treatment control conditions: BMI (-1.25kg/m(2), 95% confidence interval [CI] -2.18 to -0.32) and BMI z score (-0.10, 95% CI -0.18 to -0.02). Studies comparing lifestyle interventions to usual care also resulted in significant immediate (-1.30kg/m(2), 95% CI -1.58 to -1.03) and posttreatment effects (-0.92 kg/m(2), 95% CI -1.31 to -0.54) on BMI up to 1 year from baseline. Lifestyle interventions led to significant improvements in low-density lipoprotein cholesterol (-0.30 mmol/L, 95% CI -0.45 to -0.15), triglycerides (-0.15 mmol/L, 95% CI -0.24 to -0.07), fasting insulin (-55.1 pmol/L, 95% CI -71.2 to -39.1) and blood pressure up to 1 year from baseline. No differences were found for high-density lipoprotein cholesterol.

CONCLUSIONS

Lifestyle interventions can lead to improvements in weight and cardio-metabolic outcomes. Further research is needed to determine the optimal length, intensity, and long-term effectiveness of lifestyle interventions.

Physical activity is related to insulin sensitivity in children and adolescents, independent of adiposity: a review of the literature

In adults, there is evidence that physical activity effectively improves insulin sensitivity regardless of adiposity. Whether this is also the case in children and adolescents is less clear. Clarifying this matter may help to identify the best outcomes to target in exercise programs for these age groups, where changes in adiposity may not always be desirable or realistic. A review of the literature was conducted on studies that examined the relationships of physical activity, cardiorespiratory fitness and strength with insulin sensitivity independent of adiposity in children and adolescents. Experimental (intervention) and correlational (longitudinal and cross-sectional) studies on participants ages 18 years and younger were identified. A total of 42 studies were included in this review. Sample sizes in the studies ranged from 14 to 4955 participants, with individual ages ranging from 5 to 19 years. A significant relationship with insulin sensitivity existed in 78% of studies on physical activity, 69% of studies on cardiorespiratory fitness and 66% of studies on strength. In studies that examined both physical activity and cardiorespiratory fitness concurrently, evidence suggests that they are both correlated with insulin sensitivity independent of adiposity, especially when physical activity is at higher intensities. However, the strength of this relationship might be influenced by study design, measurement techniques and participant characteristics. This is the first review of its type to take research design into account and to examine study outcomes according to participant ethnicity, gender, age, pubertal status and weight status.

Healthy Eating, Aerobic and Resistance Training in Youth (HEARTY): study rationale, design and methods

PURPOSE

The objective of the Healthy Eating Aerobic and Resistance Training in Youth (HEARTY) trial (ClinicalTrials.Gov # NCT00195858) was to examine the effects of resistance training, with and without aerobic training, on percent body fat in sedentary, post-pubertal overweight or obese adolescents aged 14-18 years. This paper describes the HEARTY study rationale, design and methods.

METHODS

After a 4-week supervised low-intensity exercise run-in period, 304 overweight or obese adolescents with a body mass index≥85th percentile for age and sex were randomized to 4 groups for 22 weeks (5 months): diet+aerobic exercise, diet+resistance exercise, diet+combined aerobic and resistance exercise, or a diet only waiting-list control. All participants received dietary counseling designed to promote healthy eating with a maximum daily energy deficit of -250 kcal.

OUTCOMES

The primary outcome is percent body fat measured by Magnetic Resonance Imaging. Secondary outcomes include changes in anthropometry, regional body composition, resting energy expenditure, cardiorespiratory fitness, musculoskeletal fitness, cardiometabolic risk markers, and psychological health.

SUMMARY

To our knowledge, HEARTY is the largest clinical trial examining effects of aerobic training, resistance training, and combined aerobic and resistance training on changes in adiposity and cardiometabolic risk markers in overweight and obese adolescents. The findings will have important clinical implications regarding the role that resistance training should play in the management of adolescent obesity and its co-morbidities.