Intermittent Energy Restriction Is a Feasible, Effective, and Acceptable Intervention to Treat Adolescents with Obesity

Intermittent Energy Restriction for Adolescents With Obesity: The Fast Track to Health Randomized Clinical Trial

Importance

Adolescent obesity requires effective and accessible treatment. Intensive dietary interventions have the potential to be used as adjunctive therapy for behavioral weight management.

Objective

To examine the effectiveness of 2 diet therapies, delivered as part of an intensive behavioral weight management intervention, in adolescents with metabolic complications associated with obesity.

Design, Setting, and Participants

This multisite, 52-week randomized clinical trial was conducted from January 31, 2018, to March 31, 2023, at 2 tertiary pediatric centers in Australia. Adolescents (aged 13-17 years) with obesity and 1 or more associated complications were included.

Interventions

Intensive behavioral interventions, delivered by a multidisciplinary team, comparing intermittent energy restriction (IER) or continuous energy restriction (CER), with 3 phases: very low-energy diet (weeks 0-4), intensive intervention (weeks 5-16), and continued intervention and/or maintenance (weeks 17-52).

Main Outcomes and Measures

The primary outcome was body mass index (BMI) z score at 52 weeks in the IER vs CER group. Anthropometry, body composition, and cardiometabolic health were assessed at baseline and 52 weeks. The BMI z score and percentiles were determined using Centers for Disease Control and Prevention growth charts. Insulin resistance, dyslipidemia, and elevated hepatic function were assessed.

Results

A total of 141 adolescents (median [IQR] age, 14.8 [12.9-17.9] years; 71 male [50.4%]) were enrolled, 71 in the IER group and 70 in the CER group, and 97 (68.8%) completed the intervention, 43 in the IER group and 54 in the CER group. At week 52, both groups had reduced BMI z scores (estimated marginal mean change, -0.28 [95% CI, -0.37 to -0.20] for IER and -0.28 [95% CI, -0.36 to -0.20] for CER) and reduced BMI expressed as a percentage of the 95th percentile (estimated marginal mean change, -9.56 [95% CI, -12.36 to -6.83] for IER and -9.23 [95% CI, -11.82 to -6.64] for CER). No differences were found in body composition or cardiometabolic outcomes between the groups. Both groups had a reduction in the occurrence of insulin resistance (from 52 of 68 [76.5%] to 32 of 56 [57.1%] in the IER group and from 59 of 68 [86.8%] to 31 of 60 [57.1%] in the CER group) at week 16; however, at week 52, this effect was observed in the CER group only (from 59 of 68 [86.7%] to 30 of 49 [61.2%]). The occurrence of dyslipidemia was unchanged between baseline and week 52 (60 of 137 [42.6%] and 37 of 87 [42.5%], respectively), with a small improvement in occurrence of impaired hepatic function tests (37 of 139 [27.0%] and 15 of 87 [17.2%], respectively). No differences were found in dyslipidemia or hepatic function between groups.

Conclusions and Relevance

These findings suggest that for adolescents with obesity-associated complications, IER can be incorporated into a behavioral weight management program, providing an option in addition to CER and offering participants more choice.

Trial Registration

http://anzctr.org.au Identifier: ACTRN12617001630303.

Eating behaviour characteristics and dietary intake among Japanese junior high school students: A cross-sectional study

BACKGROUND

Psychological characteristics of eating behaviour may be related to dietary habits.

AIM

We investigated the association between eating behaviour characteristics and nutrition and food intake adequacy in Japanese adolescents.

METHODS

This cross-sectional survey was conducted among 136 junior high school students (boys: 90, girls: 46) at a junior high school in Tokyo, Japan. Eating behaviour was categorised into three types (emotional, external, and restrained) using scores on the Japanese version of the Dutch Eating Behaviour Questionnaire. Dietary intake was assessed using a validated, brief self-administered diet history questionnaire. Inadequate nutrient intake was determined by counting the number of nutrients not meeting the dietary reference intake (DRI) for the Japanese population. The statistical analyses included Wilcoxon signed-rank tests, Spearman's rank correlation coefficient, and multiple regression analysis using JMP ver.14 (SAS Institute Inc., Cary, NC, USA). All reported p values are two-tailed, and p < 0.05 was regarded as statistically significant.

RESULTS

Multiple regression analysis showed that restrained eating score was inversely associated with the number of nutrients not meeting the DRI (β =  - 0.28; p = 0.0027) and with total weight of snack intake (β =  - 0.30; p = 0.0010). Neither emotional nor external eating was significantly associated with the number of nutrients not meeting the DRI and with total weight of snack intake.

CONCLUSIONS

These results suggest that adolescents with low restrained eating scores may have less self-control over their eating behaviour and may therefore have inadequate dietary intake.

From fasting to fat reshaping: exploring the molecular pathways of intermittent fasting-induced adipose tissue remodeling

Obesity, characterised by excessive fat accumulation, is a complex chronic condition that results from dysfunctional adipose tissue expansion due to prolonged calorie surplus. This leads to rapid adipocyte enlargement that exceeds the support capacity of the surrounding neurovascular network, resulting in increased hypoxia, inflammation, and insulin resistance. Intermittent fasting (IF), a dietary regimen that cycles between periods of fasting and eating, has emerged as an effective strategy to combat obesity and improve metabolic homeostasis by promoting healthy adipose tissue remodeling. However, the precise molecular and cellular mechanisms behind the metabolic improvements and remodeling of white adipose tissue (WAT) driven by IF remain elusive. This review aims to summarise and discuss the relationship between IF and adipose tissue remodeling and explore the potential mechanisms through which IF induces alterations in WAT. This includes several key structural changes, including angiogenesis and sympathetic innervation of WAT. We will also discuss the involvement of key signalling pathways, such as PI3K, SIRT, mTOR, and AMPK, which potentially play a crucial role in IF-mediated metabolic adaptations.

Intermittent Fasting in Youth: A Scoping Review

Intermittent fasting (IF) focuses on the timing of eating rather than diet quality or energy intake, with evidence supporting its effects on weight loss and cardiometabolic outcomes in adults. However, there is limited evidence for its efficacy in adolescents and emerging adults. To address this, a scoping review examined IF regimens in individuals aged 10 to 25, focusing on methodology, intervention parameters, outcomes, adherence, feasibility, and efficacy. The review included 39 studies with 731 participants aged 15 to 25. Methodologies varied, with 18 studies on time-restricted eating and others requiring caloric restriction. Primary outcomes included cardiometabolic risk factors (11/29), body composition (9/29), anthropometric measurements (8/29), and feasibility (2/29). Most studies reported significant weight loss. This review underscores IF's potential in treating obesity in this age group but highlights the need for rigorous studies with standardized frameworks for feasibility to ensure comparability and determine IF's practicality in this age group.

Genetics, pharmacotherapy, and dietary interventions in childhood obesity

Childhood obesity has emerged as a major global health issue, contributing to the increased prevalence of chronic conditions and adversely affecting the quality of life and future prospects of affected individuals, thereby presenting a substantial societal challenge. This complex condition, influenced by the interplay of genetic predispositions and environmental factors, is characterized by excessive energy intake due to uncontrolled appetite regulation and a Westernized diet. Managing obesity in childhood requires specific considerations compared with adulthood, given the vulnerability of the critical juvenile-adolescent period to toxicity and developmental defects. Consequently, common treatment options for adult obesity may not directly apply to younger populations. Therefore, research on childhood obesity has focused on genetic defects in regulating energy intake, alongside pharmacotherapy and dietary interventions as management approaches, with an emphasis on safety concerns. This review aims to summarize canonical knowledge and recent findings on genetic factors contributing to childhood obesity. Additionally, it assesses the efficacy and safety of existing pharmacotherapies and dietary interventions and suggests future research directions. By providing a comprehensive understanding of the complex dynamics of childhood obesity, this review aims to offer insights into more targeted and effective strategies for addressing this condition, including personalized healthcare solutions.

Clinical potential of fasting in type 1 diabetes

Most adults with type 1 diabetes (T1DM) are either overweight or obese. As such, dietary management is recommended as an adjunct to insulin treatment to improve glycemic control and facilitate weight loss in these patients. Time-restricted eating (TRE) is a form of intermittent fasting that offers a simplified approach to treating obesity in T1DM. TRE typically involves restricting eating to 6 to 10 h per day, with water and medications allowed outside the eating window. This review examines the efficacy of TRE and other fasting protocols in improving weight and glycemic control in patients with obesity and T1DM. This review will also evaluate the safety of these regimens and provide advice to clinicians on implementing intermittent fasting in T1DM.

Participant recruitment for paediatric research using social media: A practical 'how-to' guide for researchers

AIM

Social media platforms are being increasingly used to support participant recruitment into paediatric health-related research. This study aimed to develop a multi-phase approach for using social media as a recruitment strategy for paediatric research studies.

METHODS

The process was informed by the authors' prior experiences recruiting for paediatric obesity-related research studies, expertise in social media marketing and digital participant/ patient recruitment. Reflection on these experiences resulted in the iterative creation of a draft process which was further refined. A narrative literature review using a structured search was conducted to refine and augment the content and finalise the process.

RESULTS

A six-phase recruitment approach was developed that includes: (i) plan for social media use as a recruitment strategy, (ii) explore relevant ethical considerations to protect the wellbeing of potentially vulnerable groups and create an ethical management plan, (iii) identify and understand the different target audiences and develop the advertising strategy, (iv) develop and design campaign content, (v) implement, monitor and iteratively refine the recruitment campaign, (vi) evaluate the campaign success. Potential activities and key considerations relevant for paediatric research are presented within each phase.

CONCLUSION

Due to the widespread use and diverse characteristics of social media users, social media has the potential to disseminate details of research opportunities to community members who may otherwise not hear about, engage with, and potentially benefit from research participation. Researchers should collaborate with communication experts and target audiences to generate relevant and effective recruitment campaigns. Researchers should implement processes to protect vulnerable audiences' wellbeing at each stage of the process. Recruitment via social media may support wider community participation in research studies designed to improve young people's health.

Intermittent dietary carbohydrate restriction versus calorie restriction and cardiometabolic profiles: A randomized trial

OBJECTIVE

The aim of this study was to investigate the effectiveness of an intermittent low-carbohydrate diet (ILCD) versus calorie restriction (ICR) in young populations and potential mechanisms.

METHODS

Thirty-four participants aged 9 to 30 years with cardiometabolic risk were randomized to receive a self-administered 2-week ILCD (carbohydrate intake ≤ 50 g/d on seven nonconsecutive days) or ICR (500-600 kcal/d for two consecutive days per week). Differences in changes in obesity measures, glycemic and lipid profiles, gut microbiota composition, and three serum biomarkers were compared.

RESULTS

The ILCD and ICR similarly reduced body weight, waist circumference, fasting glucose, insulin, postprandial glucose variation, monocyte chemoattractant protein-1, free fatty acid, and fibroblast growth factor 21, whereas ILCD produced significantly different alterations in the following outcomes compared with ICR: greater increases in low-density lipoprotein cholesterol and total cholesterol (-0.36 mmol/L, 95% CI: -0.68 to -0.04; -0.40 mmol/L, 95% CI: -0.73 to -0.06) and greater decrease in triglyceride (0.20 mmol/L, 95% CI: 0.04 to 0.37). Actinobacteria and Bifidobacterium reduced after ILCD but not ICR; and the reductions strongly correlated with changes in fasting glucose (both r = 0.84) and low-density lipoprotein cholesterol (r = -0.81 and -0.72).

CONCLUSIONS

This study found no evidence of differences in changes from baseline in obesity measures, glucose regulation, and inflammation between ILCD and ICR, despite trends in reduction in those parameters. However, there seemed to be some differences in responses in lipids and gut microbiota.

Intermittent energy restriction changes the regional homogeneity of the obese human brain

Background

Intermittent energy restriction (IER) is an effective weight loss strategy. However, the accompanying changes in spontaneous neural activity are unclear, and the relationship among anthropometric measurements, biochemical indicators, and adipokines remains ambiguous.

Methods

Thirty-five obese adults were recruited and received a 2-month IER intervention. Data were collected from anthropometric measurements, blood samples, and resting-state functional magnetic resonance imaging at four time points. The regional homogeneity (ReHo) method was used to explore the effects of the IER intervention. The relationships between the ReHo values of altered brain regions and changes in anthropometric measurements, biochemical indicators, and adipokines (leptin and adiponectin) were analyzed.

Results

Results showed that IER significantly improved anthropometric measurements, biochemical indicators, and adipokine levels in the successful weight loss group. The IER intervention for weight loss was associated with a significant increase in ReHo in the bilateral lingual gyrus, left calcarine, and left postcentral gyrus and a significant decrease in the right middle temporal gyrus and right cerebellum (VIII). Follow-up analyses showed that the increase in ReHo values in the right LG had a significant positive correlation with a reduction in Three-factor Eating Questionnaire (TFEQ)-disinhibition and a significant negative correlation with an increase in TFEQ-cognitive control. Furthermore, the increase in ReHo values in the left calcarine had a significant positive correlation with the reduction in TFEQ-disinhibition. However, no significant difference in ReHo was observed in the failed weight loss group.

Conclusion

Our study provides objective evidence that the IER intervention reshaped the ReHo of some brain regions in obese individuals, accompanied with improved anthropometric measurements, biochemical indicators, and adipokines. These results illustrated that the IER intervention for weight loss may act by decreasing the motivational drive to eat, reducing reward responses to food cues, and repairing damaged food-related self-control processes. These findings enhance our understanding of the neurobiological basis of IER for weight loss in obesity.

Preventative interventions that target cardiovascular dysfunction in children and young people: a systematic review of their effectiveness and an investigation of sexual dimorphism

Given that cardiovascular diseases remain a primary cause of mortality and morbidity, there is a need to consider preventative strategies to improve vascular function from early in life. The aims of this study were therefore to investigate which interventions may improve endothelial function, intima media thickness and arterial stiffness in children and young people and to assess whether these interventions differ in boys and girls. A systematic literature search of Science Direct, Pubmed, Google Scholar and the Cochrane Library by two independent reviewers was performed to source articles. Inclusion criteria were any studies including any child ≤18 years of age receiving an intervention, which measured vascular function other than blood pressure. Exclusion criteria were studies assessing children with chronic medical conditions. A total of 72 studies were identified, which met the inclusion criteria. A measurable change in outcome was more likely to be reported in studies investigating endothelial function (p = 0.03). Interventions which improved vascular function included physical activity and dietary programmes. Under 10% of studies considered sex differences. In conclusion, school-based physical activity interventions are most likely to result in improvements in vascular function. Endothelial function may be the first variable of vascular function to change secondary to an intervention. Standardisation of reporting of differences between the sexes is essential to be able to ensure interventions are equally effective for boys and girls.

Time-Restricted Feeding and Intermittent Fasting as Preventive Therapeutics: A Systematic Review of the Literature

Multiple studies have shown that intermittent fasting (IF) is associated with better health conditions and longer lifespans, as is time-restricted feeding (TRF). One crucial explanation is that IF and TRF permit a set length of time for caloric ingestion, during which our systems activate a variety of mechanisms that lead to the enhancement and renewal of different body systems. Accordingly, the benefits of IF and TRF are a lot greater than those of complete calorie restriction (CR). Accordingly, TRF and IF offered the underpinnings for human studies that revealed that when we eat and when we are fasting, we experience fluctuations in all body systems. For relevant medical literature, we investigated medical databases such as PubMed/Medline, PubMed Central, Cochrane Library, and Google Scholar. The chosen articles were evaluated based on eligibility criteria and vetted by quality evaluation methods; 15 finished research papers were included in the study. Of the 15 recognized studies, four were systematic reviews of literature, and 11 were review articles. The chosen publications all examined the efficacy and comparability with other restrictive diets. The study articles indicated that the advantages of IF and TRF represent complex interplay involving periodic digestion of food, gut flora, and the circadian clock. Accordingly, further research is necessary to get a comprehensive grasp of this very complex molecular blueprint. This could aid in producing an effectively planned food treatment that can regulate numerous chronic health ailments and disorders. Furthermore, it might lead to the development and investigation of new pharmacological medicines that mimic the nutritional and therapeutic benefits of IF for those who are unwilling or unable to follow this kind of feeding regimen.

Nutritional Approaches in Children with Overweight or Obesity and Hepatic Steatosis

Childhood obesity is a global public health problem. Worldwide, 41 million children under 5 years and 340 million children and adolescents between 5 and 19 years are overweight. In addition, the recent COVID-19 epidemic has further amplified this social phenomenon. Obesity is a condition associated with various comorbidities, such as nonalcoholic fatty liver disease (NAFLD). The pathophysiology of NAFLD in obesity is intricate and involves the interaction and dysregulation of several mechanisms, such as insulin resistance, cytokine signaling, and alteration of the gut microbiota. NAFLD is defined as the presence of hepatic steatosis in more than 5% of hepatocytes, evaluated by histological analysis. It can evolve from hepatic steatosis to steatohepatitis, fibrosis, cirrhosis, hepatocellular carcinoma, and end-stage liver failure. Body weight reduction through lifestyle modification remains the first-line intervention for the management of pediatric NAFLD. Indeed, studies suggest that diets low in fat and sugar and conversely rich in dietary fibers promote the improvement of metabolic parameters. This review aims to evaluate the existing relationship between obesity and NAFLD in the pediatric population and to assess the dietary patterns and nutritional supplementations that can be recommended to prevent and manage obesity and its comorbidities.

Adolescents with Type 2 Diabetes: Overcoming Barriers to Effective Weight Management

The prevalence of type 2 diabetes (T2DM) among children and adolescents has remarkably increased in the last two decades, particularly among ethnic minorities. Management of T2DM is challenging in the adolescent population due to a constellation of factors, including biological, socioeconomic, cultural, and psychological barriers. Weight reduction is an essential component in management of T2DM as weight loss is associated with improvement in insulin sensitivity and glycemic status. A family centered and culturally appropriate approach offered by a multidisciplinary team is crucial to address the biological, psychosocial, cultural, and financial barriers to weight management in youth with T2DM. Lifestyle interventions and pharmacotherapy have shown modest efficacy in achieving weight reduction in adolescents with T2DM. Bariatric surgery is associated with excellent weight reduction and remission of T2DM in youth. Emerging therapies for weight reduction in youth include digital technologies, newer GLP-1 agonists and endoscopic procedures.

A time-restricted feeding intervention in children and adolescents with obesity: The TRansForm study protocol

Obesity during childhood is of special concern as adiposity is typically tracked into adult life and it constitutes a major risk factor for future obesity and associated metabolic disorders. Recent studies indicate that time-restricted feeding (TRF) interventions may provide a promising strategy for obesity treatment. However, TRF interventions have only been tested in adult subjects. This study aims to determine both short- and long-term effects of a TRF intervention in children and adolescents with obesity. We will also investigate potential mechanisms mediating the response to the intervention, including the circadian rhythm and the gut microbiota composition. We have designed a randomized-controlled parallel-group clinical study in which children and adolescents (age range 8–18 year-old) with obesity will be subjected to time-restricted eating or no time restrictions for 2 months. Follow-up visits will allow for long-term effect assessments. We will measure anthropometric (BMI, body composition) and metabolic parameters (glucose and lipid metabolism), indicators of the circadian rhythm, and gut microbiota composition will be analyzed. This study will (1) determine safety and effectiveness of the TRF intervention in children and adolescents; (2) assess its long-term effects; and (3) evaluate potential mechanisms involved in the response to the intervention.

Clinical trial registration

[www.ClinicalTrials.gov], identifier [NCT05174871].

Obesity in children and adolescents: epidemiology, causes, assessment, and management

This Review describes current knowledge on the epidemiology and causes of child and adolescent obesity, considerations for assessment, and current management approaches. Before the COVID-19 pandemic, obesity prevalence in children and adolescents had plateaued in many high-income countries despite levels of severe obesity having increased. However, in low-income and middle-income countries, obesity prevalence had risen. During the pandemic, weight gain among children and adolescents has increased in several jurisdictions. Obesity is associated with cardiometabolic and psychosocial comorbidity as well as premature adult mortality. The development and perpetuation of obesity is largely explained by a bio-socioecological framework, whereby biological predisposition, socioeconomic, and environmental factors interact together to promote deposition and proliferation of adipose tissue. First-line treatment approaches include family-based behavioural obesity interventions addressing diet, physical activity, sedentary behaviours, and sleep quality, underpinned by behaviour change strategies. Evidence for intensive dietary approaches, pharmacotherapy, and metabolic and bariatric surgery as supplemental therapies are emerging; however, access to these therapies is scarce in most jurisdictions. Research is still needed to inform the personalisation of treatment approaches of obesity in children and adolescents and their translation to clinical practice.

Clinical application of intermittent fasting for weight loss: progress and future directions

Intermittent fasting diets have become very popular in the past few years, as they can produce clinically significant weight loss. These diets can be defined, in the simplest of terms, as periods of fasting alternating with periods of eating. The most studied forms of intermittent fasting include: alternate day fasting (0-500 kcal per 'fast day' alternating with ad libitum intake on 'feast days'); the 5:2 diet (two fast days and five feast days per week) and time-restricted eating (only eating within a prescribed window of time each day). Despite the recent surge in the popularity of fasting, only a few studies have examined the health benefits of these diets in humans. The goal of this Review is to summarize these preliminary findings and give insights into the effects of intermittent fasting on body weight and risk factors for cardiometabolic diseases in humans. This Review also assesses the safety of these regimens, and offers some practical advice for how to incorporate intermittent fasting diets into everyday life. Recommendations for future research are also presented.

Beneficial effects of intermittent fasting: a narrative review

Caloric restriction is a popular approach to treat obesity and its associated chronic illnesses but is difficult to maintain for a long time. Intermittent fasting is an alternative and easily applicable dietary intervention for caloric restriction. Moreover, intermittent fasting has beneficial effects equivalent to those of caloric restriction in terms of body weight control, improvements in glucose homeostasis and lipid profiles, and anti-inflammatory effects. In this review, the beneficial effects of intermittent fasting are discussed.

Intermittent Fasting: Potential Bridge of Obesity and Diabetes to Health?

Obesity has been an escalating worldwide health problem for decades, and it is likely a risk factor of prediabetes and diabetes. Correlated with obesity, the number of diabetic patients is also remarkable. A modest weight loss (5–10%) is critical to alleviate the risk of any other metabolic disease. Reduced energy intake has been an essential factor for weight loss reduction. As a new behavior intervention to lose weight, intermittent fasting (IF) attracts considerable attention and has become a popular strategy among young people. IF is a diet pattern that cycles between periods of fasting and eating on a regular schedule, involving various types, mainly Intermittent Energy Restriction and Time-Restricted Fasting. Accumulating evidence shows that short-term IF has a greatly positive effect in animal studies and contributes favorable benefits in human trials as well. Nevertheless, as an emerging, diverse, and relatively premature behavior intervention, there are still limited studies considering patients with obesity and type 2 diabetes mellitus. It is also a controversial intervention for the treatment of metabolic disease and cancer. The risks and challenges appear consequently. Additionally, whether intermittent fasting can be applied to long-term clinical treatment, and whether it has side effects during the long-term period or not, demands more large-scale and long-term experiments.

Effects of intermittent very-low calorie diet on glycemic control and cardiovascular risk factors in obese patients with type 2 diabetes mellitus: A randomized controlled trial

AIMS/INTRODUCTION

Very few studies assess the effectiveness of different protocols of intermittent very-low calorie diet (VLCD) in patients with diabetes. This study was designed to compare the effects of 2 days/week and 4 days/week of intermittent VLCD on glycemic control, diabetes remission, metabolic parameters and quality of life in patients with type 2 diabetes and obesity.

MATERIALS AND METHODS

Participants with obesity and type 2 diabetes were recruited and randomly assigned to three groups, consisting of control, 2 days/week and 4 days/week of intermittent VLCD. In the intermittent VLCD groups, participants received a 600-kcal diet per day on restricted days and ad libitum food consumption on non-restricted days. Glycemic control, rate of diabetes remission, metabolic parameters and quality of life were evaluated at baseline, weeks 2, 10 and 20.

RESULTS

A total of 40 participants were enrolled. The mean body mass index was 30.1 ± 5.9 kg/m2 , and the mean glycated hemoglobin was 7.4 ± 1.2%. At week 20, there was an improvement in glycemic control in both intermittent VLCD groups with significant decreases in glycated hemoglobin levels and insulin resistance index throughout the study periods. Diabetes remission without the need for medications was equally found in 29% of participants in both intermittent VLCD groups. Serum triglyceride, bodyweight, body mass index and fat mass were also significantly decreased in both VLCD groups. No serious adverse events were encountered.

CONCLUSION

Intermittent VLCD was highly effective in achieving optimal glycemic control. The effects of 2 days/week and 4 days/week of intermittent VLCD on diabetes remission were relatively similar.

Cardiometabolic Benefits of Intermittent Fasting

This review aims to summarize the effects of intermittent fasting on markers of cardiometabolic health in humans. All forms of fasting reviewed here-alternate-day fasting (ADF), the 5:2 diet, and time-restricted eating (TRE)-produced mild to moderate weight loss (1-8% from baseline) and consistent reductions in energy intake (10-30% from baseline). These regimens may benefit cardiometabolic health by decreasing blood pressure, insulin resistance, and oxidative stress. Low-density lipoprotein cholesterol and triglyceride levels are also lowered, but findings are variable. Other health benefits, such as improved appetite regulation and favorable changes in the diversity of the gut microbiome, have also been demonstrated, but evidence for these effects is limited. Intermittent fasting is generally safe and does not result in energy level disturbances or increased disordered eating behaviors. In summary, intermittent fasting is a safe diet therapy that can produce clinically significant weight loss (>5%) and improve several markers of metabolic health in individuals with obesity.

The role of structure in dietary approaches for the treatment of pediatric overweight and obesity: A critical review

A multicomponent approach for the treatment of pediatric overweight/obesity, which includes behavioral strategies to alter diet and physical activity/sedentary behavior, has graded recommendations for its use. Dietary interventions to be used within this approach do not. In adults, research indicates that strongly graded dietary interventions providing greater structure (or more control over the types/amount of food consumed) produce better weight outcomes. For this critical review, dietary interventions recommended by the Expert Committee for the treatment of pediatric overweight/obesity were categorized according to their potential degree of dietary structure, and their impact on weight outcomes was described. Four levels of dietary structure were reviewed, operationalized as alterations to the following: food groups, such as fruits and vegetables (low structure); daily eating occasions, such as meals (moderate structure); large nutrients, such as energy (high structure); and energy plus additional dietary alterations (very high structure). In total, 24 interventions (four low, three moderate, five high, and 12 very high structure structure) were identified and reviewed. Reductions in standardized body mass index increased with increasing structure, and interventions ≥6 months had better outcomes than interventions <6 months. Future research should empirically test dietary intervention structure to determine its impact on weight status during pediatric overweight/obesity treatment.

Novel dietary interventions for adolescents with obesity: A narrative review

Adolescent obesity is increasing and a range of treatment approaches are needed. Provision of tailored treatment options accounting for individual and family needs, preferences, and capacity may encourage adolescents with obesity to seek treatment, and/or improve treatment outcomes. Delivered by trained health care professionals, novel dietary interventions may have utility for adolescents not responding to conventional diets, adolescents with comorbidities or severe obesity, and/or when rapid or substantial weight loss is required. This review describes current evidence and clinical considerations relating to the use of very low energy diets, low carbohydrate diets, and intermittent energy restriction in the treatment of adolescent obesity. Emerging evidence on the use of these novel dietary interventions demonstrates short-term weight-related and cardiometabolic improvements. While the evidence is encouraging, and no serious adverse effects have been reported, monitoring of intervention safety is essential. Considerations for health care professionals providing care to adolescents include nutritional adequacy, psychosocial health and social relationships during the intervention. Furthermore, long-term weight-related, cardiometabolic and psychological health outcomes of these dietary interventions are not well understood. Large randomised controlled trials are warranted to inform clinical practice and future guidelines for the use of novel dietary interventions in adolescents with obesity.

Timing of food consumption in Hispanic adolescents with obesity

BACKGROUND

Little is known about the normal eating time periods in adolescents with obesity and how these patterns change throughout development. As the obesity epidemic continues to rise in adolescence, it becomes imperative to understand developmentally appropriate eating behaviours and to create weight management strategies that build on those innate patterns and preferences. The purpose of this study was to determine the most common habitual eating windows observed in adolescents with obesity.

METHODS

Participants were 101 Hispanic adolescents (mean age 14.8 ± 2.1 years; 48 male/53 female) with obesity (BMI ≥95th percentile) who were recruited as part of a larger clinical trial. Dietary intake and meal timing was determined using multiple pass 24-hours recalls. Histograms were utilized to determine the natural distribution of percent consumption of total kilocalories, carbohydrates and added sugar per hour.

RESULTS

The majority of total kilocalories (65.4%), carbohydrates (65.3%) and added sugar (59.1%) occurred between 11:00 and 19:00. Adolescents were 2.5 to 2.9 times more likely to consume kilocalories, carbohydrates, and added sugar during the 8-hour window between 11:00 am and 19:00 pm than other time windows examined (all P < .001). The consumption of these calories did not differ between weekdays and weekend (P > .05) or by sex.

CONCLUSIONS

In this cohort, more than 60% of calories, carbohydrates and added sugar were consumed between 11:00 am and 19:00 pm, which is concordant with an afternoon/evening chronotype that is common in adolescents. Our findings support this 8-hour period as a practical window for weight loss interventions that target pre-specified eating periods in this population.

Eating disorder risk in adolescents with obesity

The intersection between adolescent obesity and eating disorder risk is one that requires urgent attention. This review aimed to synthesize the literature on the risk of clinical eating disorders in adolescents with obesity, discuss challenges with assessing risk, and examine implications for clinical practice and future research. Obesity and eating disorders can coexist resulting in exacerbated physical and psychological health issues. Recognized eating disorder risk factors, including body dissatisfaction, poor self-esteem, depression, and engaging in dieting behaviors, are elevated and frequently reported in adolescents with obesity, highlighting a vulnerability to the development of eating disorders. Unsupervised dieting to manage weight may exacerbate eating disorder risk, while structured and supervised weight management is likely to reduce eating disorder risk for most adolescents. However, some adolescents may present to an obesity service with an undiagnosed eating disorder or may develop an eating disorder during or following treatment. We conclude that a risk management approach, with screening or monitoring for eating disorder-related risk factors and behaviors, should be utilized to identify those at risk. Future research to identify eating disorder risk factors specific to adolescents with obesity is required to inform screening and monitoring protocols, patient care, and address current knowledge gaps.

Alternative diets among adolescents: facts or fads?

PURPOSE OF REVIEW

With rising rates of chronic noninfectious diseases across the United States thought to be associated with the average American diet, many have adopted alternative diets. Most of these diets promise weight reduction via adherence to strict dietary guidelines, often removing certain types of food. With access to a plethora of information online, it is easy for adolescents to become confused when making dietary decisions. Although these diets promise benefits, it is important to understand common shortcomings and how to overcome them for safe implementation among adolescents.

RECENT FINDINGS

This review discusses the theory, implementation, and risks associated with intermittent fasting as well as vegetarian, vegan, ketogenic, Atkins, Paleolithic, and Mediterranean diets. These considerations are further modified for pediatric populations with a focus on the social influences on dieting.

SUMMARY

Although these diets may be promising, successful adherence to them requires addressing possible shortcomings associated with a certain diet. Pediatricians should be aware of how these dietary strategies may be properly implemented in order to prevent any harm to the patient. Empowering the patient and their families through informational resources is recommended. Pediatricians should also discuss motivations underlying their patient's dietary changes in order to determine whether these motivations are healthy.

Pediatric weight management, dietary restraint, dieting, and eating disorder risk: a systematic review

CONTEXT

Whether dietary restraint and dieting are risk factors associated with eating disorders has not been explored in the context of pediatric weight management.

OBJECTIVE

To review associations between dietary pediatric weight management, dietary restraint, dieting, and eating disorder risk.

DATA SOURCES, SELECTION, AND EXTRACTION

Four databases - MEDLINE, EMBASE, Cochrane Library, and PsycINFO - were searched to May 2020 to identify pediatric weight management interventions with a dietary component for children and adolescents with overweight or obesity. The review was limited to studies reporting dietary restraint and/or dieting at preintervention, postintervention, and/or follow-up. Screening and quality assessment were conducted in duplicate, and data extraction was completed by 1 reviewer and cross-checked for accuracy. Data extracted included study characteristics, dietary restraint/dieting, and eating disorder-related outcomes (including disordered eating, body image, self-esteem, depression, and anxiety).

RESULTS

A total of 26 papers, representing 23 studies, were included. Of these, 20 studies reported on dietary restraint, which increased (10 postintervention, 6 follow-up) or remained unchanged (7 postintervention, 5 follow-up), and 5 studies reported on dieting, which increased (1 study), remained unchanged (2 studies) or decreased (2 studies) postintervention. All studies that reported on other eating disorder risk factors (eg, binge eating, body dissatisfaction, and depression) and weight-related outcomes found improvement or no change postintervention or at follow-up.

CONCLUSION

The results of this review suggest that current measures of dietary restraint and dieting are not associated with eating disorder risk within the context of pediatric weight management; however, long-term data is limited. In addition, those current measures may not be suitable risk markers. Concerns about dietary restraint and dieting leading to eating disorders should not prevent access to quality care for young people with obesity.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. 2017 CRD42017069488.

Efficacy of Weight Reduction on Pediatric Nonalcoholic Fatty Liver Disease: Opportunities to Improve Treatment Outcomes Through Pharmacotherapy

Obesity is the single greatest risk factor for nonalcoholic fatty liver disease (NAFLD). Without intervention, most pediatric patients with NAFLD continue to gain excessive weight, making early, effective weight loss intervention key for disease treatment and prevention of NAFLD progression. Unfortunately, outside of a closely monitored research setting, which is not representative of the real world, lifestyle modification success for weight loss in children is low. Bariatric surgery, though effective, is invasive and can worsen NAFLD postoperatively. Thus, there is an evolving and underutilized role for pharmacotherapy in children, both for weight reduction and NAFLD management. In this perspective article, we provide an overview of the efficacy of weight reduction on pediatric NAFLD treatment, discuss the pros and cons of currently approved pharmacotherapy options, as well as drugs commonly used off-label for weight reduction in children and adolescents. We also highlight gaps in, and opportunities for, streamlining obesity trials to include NAFLD assessment as a valuable, secondary, therapeutic outcome measure, which may aid drug repurposing. Finally, we describe the already available, and emerging, minimally-invasive biomarkers of NAFLD that could offer a safe and convenient alternative to liver biopsy in pediatric obesity and NAFLD trials.

Time limited eating in adolescents with obesity (time LEAd): Study protocol

BACKGROUND

Time limited eating (TLE) has been shown to be effective for weight loss and improvement of glycemic control in adults with obesity and type 2 diabetes (T2D), but has not been well studied in adolescents. TLE may be a more feasible, flexible and effective dietary intervention for adolescents because it removes the need for intensive counting of calories or macronutrients, and emphasizes eating during a specified time period.

OBJECTIVES

The aim of this study is to assess the feasibility of a TLE approach in adolescents with obesity using a continuous glucose monitor (CGM) to promote adherence to the intervention.

METHODS

We propose a prospective, randomized controlled trial, in 60 adolescents (ages 14-18) with obesity (BMI% ≥ 95th percentile). Youth will be randomized to one of three treatment groups for a 12-week intervention: Group 1) Low sugar and carbohydrate education (LSC, 5% of total daily calories from sugar (<35 g)/day; <90 g carbohydrate (CHO)/day) + blinded CGM (used to monitor adherence and glycemic outcomes without real time feedback), Group 2) LSC + TLE (16-h fast/8-h feed for 5 days per week) + blinded CGM, and Group 3) LSC + TLE+ real time feedback via CGM (to evaluate effect of providing CGM data on intervention efficacy). Outcomes will include change in total body fat (TBF) percentage measured on DEXA scan, BMI status and fasting blood glucose at 12 weeks compared to baseline.

CONCLUSIONS

TLE is a potentially powerful lifestyle intervention that could be readily integrated into pediatric weight management programs to optimize their impact and accelerate healthy changes.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03954223.

Strategies in the Management of Adolescent Obesity

Purpose of Review

We review the current options to manage adolescent obesity which include nutrition, physical activity, behavior modification, sleep management, pharmacotherapy and surgery. Since lifestyle interventions alone are often not effective in adolescents, a multi-disciplinary treatment approach is necessary in management.

Recent Findings

Medications (often used off-label) and metabolic/bariatric surgery are effective treatment strategies to treat adolescents with severe obesity.

Summary

The use of pharmacotherapy and surgery is limited due to lack of pediatric obesity tertiary care centers. With more centers, the treatment of adolescent obesity will improve and aid to decrease the prevalence of adult obesity.

Fast track to health - Intermittent energy restriction in adolescents with obesity. A randomised controlled trial study protocol

BACKGROUND

Intermittent energy restriction (IER) has shown early success in adolescents with obesity, however efficacy trials are needed. This study aims to determine if IER results in lower body mass index (BMI) z-score after 52 weeks in metabolically unhealthy adolescents with obesity compared with continuous energy restriction (CER).

METHODS/DESIGN

This is a prospective, randomised, multi-centre trial conducted in tertiary care settings, with three phases: jumpstart (weeks 0-4); intensive intervention (weeks 5-16); continued intervention and/or maintenance (weeks 17-52). During the jumpstart phase, all participants follow a very low energy diet (∼800kcal/3350kJ/day), then transition to their allocated intervention: IER or CER. IER involves three energy-restricted days/week, consuming one-third of daily energy requirements (∼600-700kcal/2500-2950kJ/day), and four days/week of a healthy meal plan. The CER, which is current standard care, has individually tailored energy prescription based on age and sex (13-14years, 1430-1670kcal/6000-7000kJ/day; 15-17years, 1670-1900kcal/7000-8000kJ/day). The study will recruit 186 (93 per arm) treatment-seeking adolescents aged 13-17years with obesity and at least one metabolic co-morbidity. The primary outcome is change in BMI z-score at 52 weeks. Secondary outcomes are changes at 4, 16 and 52 weeks in: body composition; diet quality, food choices and food patterns; cardio-metabolic risk factors; physical activity and sedentary behaviour; sleep and psycho-behavioural measures.

DISCUSSION

This study challenges existing clinical paradigms that CER is the only method for weight management in metabolically unhealthy adolescents. If successful, IER may offer an alternate medical nutrition therapy approach for those seeking treatment in tertiary settings.

CLINICAL TRIAL REGISTRATION NUMBER

ACTRN12617001630303.

Time-Limited Eating in Pediatric Patients with Obesity: A Case Series

Background

Time Limited Eating (TLE) is an effective strategy for management of obesity in adults, but there is a paucity of data that have examined its use in the clinical management of children with obesity. A TLE approach involves interspersing normal daily caloric intake with periods of prolonged calorie restriction several times per week. TLE may actually be more feasible, non-stigmatizing, flexible and effective in children, especially for adolescents, compared to alternatives like daily caloric or macronutrient restriction. This is because TLE removes the need for intensive counting of daily calorie intake or macronutrient content and focuses on a straightforward task of consuming food during a pre-specified time period. Also it avoids periods of extended caloric restriction which may interfere with growth and/or risk evoking development of eating behaviors. This case series describes four patients who trialed a TLE approach in a clinical weight management clinic and describes BMI reduction at 4 months.

Case Presentation

To date, 4 patients, ages 5-15, with varying underlying pathologies (i.e. Bardet Biedl Syndrome (BBS), previously healthy, craniopharyngioma and epilepsy) have tried a TLE type approach (16-hour fast/8-hour feed for 3-5 days per week) for 4 months and have demonstrated an average decrease in their BMI z-score compared to baseline of -0.24 SD. Patients and their families reported high degrees of satisfaction with this dietary approach.

Conclusions

Families were very satisfied with the TLE intervention and reported it was feasible, flexible and sustainable to implement in a real life setting and associated with decreased zBMI. Further investigation is required to determine if this approach is effective in both the short and long term as a weight management technique.