Dietary restriction in obese children and its relation with eating behavior, fibroblast growth factor 21 and leptin: a prospective clinical intervention study

Effect of abrupt and gradual calorie restriction regimens on biochemical and behavioral markers in obese mice model

Background: Although Calorie Restriction (CR) is primarily considered in obesity management, behavioral studies of CR and its methodology of implementation are not well-defined. Objective: The study aimed to determine the efficacy of the extensively researched method of CR-abrupt calorie restriction (ACR) and a newly proposed gradual calorie restriction (GCR) in terms of body weight, behavioral and biochemical parameters in the obese animal model-C57BL/6J mice. Design: Male obese mice were subjected to GCR regimen for 14 weeks which was compared and evaluated for anxiety-like behavior and stress levels with ACR. Plasma corticosterone was measured before initiation of CR and every three weeks following GCR and ACR, whereas plasma insulin was measured twice-after obesity induction and post 14 weeks of CR. The behavioral assessments were conducted before inducing CR and every three weeks following ACR and GCR. Results: A significant anxiety-like behavior and an increase in plasma corticosterone were observed in mice on GCR during the critical initial six weeks of CR (p < 0.05). Both groups showed a decrease in plasma glucose levels; however, the GCR group showed a significant reduction (p < 0.01). There was a significant decrease in social interaction in both groups with an increase in the latency period and a decrease in time spent with the stranger animal during the social interaction test (p < 0.05). Conclusion: The mice on GCR regimen demonstrated lesser anxiety-like behavior and low plasma corticosterone levels compared to those on ACR. This gives us a new avenue in CR research to evaluate the methodologies of implementing CR.

Effects of an interdisciplinary weight loss program on fibroblast growth factor 21 and inflammatory biomarkers in women with overweight and obesity

Objective

To investigate the effects of an interdisciplinary intervention on biomarkers of inflammation and their relationship with fibroblast growth factor 21 (FGF21) concentrations in women with overweight and obesity.

Methods

Thirty-one women were enrolled in a 12-week interdisciplinary weight loss program delivered by a team comprising an endocrinologist, nutritionist and exercise physiologist. Body composition; anthropometric measures; metabolic and inflammatory markers including adiponectin, leptin, and atrial natriuretic peptide (ANP) were assessed at baseline and post-therapy. The homeostasis model assessment of insulin resistance (HOMA-IR) and the homeostasis model assessment of adiponectin (HOMA-AD) were calculated. The participants were divided into two groups: those with increased FGF21, and those with decreased FGF21.

Results

The sample comprised women aged 32 ± 5 years with a body mass index of 33.64 ± 3.49 kg/m². Body weight, waist circumference and leptin concentration were decreased in the whole sample after therapy. However, only the group with an increase in FGF21 concentration presented significant improvements in adiponectin concentration and adiponectin/leptin ratio. Moreover, although there was a reduction of leptin in both groups, it was greater in the increased FGF21 groups. There was a reduction in ANP in the decreased FGF21 group.

Conclusion

Changes in FGF21 concentrations were different among the women participating in the weight loss program, with some having increased levels and some reduced levels. Furthermore, improvements in adiponectin and the adiponectin/leptin ratio were found only in the group with increased FGF21 concentration.

The Effect of a Life-Style Intervention Program of Diet and Exercise on Irisin and FGF-21 Concentrations in Children and Adolescents with Overweight and Obesity

Overweight and obesity in childhood and adolescence represent major public health problems of our century, and account for increased morbidity and mortality in adult life. Irisin and Fibroblast Growth Factor 21 (FGF-21) have been proposed as prognostic and/or diagnostic biomarkers in subjects with obesity and metabolic syndrome, because they increase earlier than other traditional biomarkers. We determined the concentrations of Irisin and FGF-21 in children and adolescents with overweight and obesity before and after one year of a life-style intervention program of diet and physical exercise and explored the impact of body mass index (BMI) reduction on the concentrations of Irisin, FGF-21 and other cardiometabolic risk factors. Three hundred and ten (n = 310) children and adolescents (mean age ± SD: 10.5 ± 2.9 years) were studied prospectively. Following one year of the life-style intervention program, there was a significant decrease in BMI (p = 0.001), waist-to-hip ratio (p = 0.024), waist-to-height ratio (p = 0.024), and Irisin concentrations (p = 0.001), and an improvement in cardiometabolic risk factors. There was no alteration in FGF-21 concentrations. These findings indicate that Irisin concentrations decreased significantly as a result of BMI reduction in children and adolescents with overweight and obesity. Further studies are required to investigate the potential role of Irisin as a biomarker for monitoring the response to lifestyle interventions and for predicting the development of cardiometabolic risk factors.

Effects of dietary restriction on metabolic and cognitive health

Life expectancy in most developed countries has been rising over the past century. In the UK alone, there are about 12 million people over 65 years old and centenarians have increased by 85% in the past 15 years. As a result of the ageing population, which is due mainly to improvements in medical treatments, public health, improved housing and lifestyle choices, there is an associated increase in the prevalence of pathological conditions, such as metabolic disorders, type 2 diabetes, cardiovascular and neurodegenerative diseases, many types of cancer and others. Statistics suggest that nearly 54% of elderly people in the UK live with at least two chronic conditions, revealing the urgency for identifying interventions that can prevent and/or treat such disorders. Non-pharmacological, dietary interventions such as energetic restriction (ER) and methionine restriction (MR) have revealed promising outcomes in increasing longevity and preventing and/or reversing the development of ageing-associated disorders. In this review, we discuss the evidence and mechanisms that are involved in these processes. Fibroblast growth factor 1 and hydrogen sulphide are important molecules involved in the effects of ER and MR in the extension of life span. Their role is also associated with the prevention of metabolic and cognitive disorders, highlighting these interventions as promising modulators for improvement of health span.

Leptin at birth and at age 7 in relation to appetitive behaviors at age 7 and age 10

Leptin contributes to the control of food intake and energy balance. However, its association with appetitive behaviors during childhood is not well understood. We aimed to investigate the association between leptin, assessed at birth and at 7 years of age (y), and appetitive behaviors assessed at 7 and 10 y. Children from a Portuguese cohort with assessment of leptin levels at birth from umbilical cord blood (n = 645) and at 7 y from venous blood samples (n = 587), were included. The Children's Eating Behavior Questionnaire assessed appetitive behaviors at 7 and 10 y. Weight and height were measured at 7 and 10 y to derive BMI z-scores (BMIz). A series of Generalized Linear Models tested relationships between leptin and appetitive behaviors, adjusting for potential confounders (maternal age, education, pre-pregnancy BMI, smoking during pregnancy, child physical activity and child BMIz), and interaction terms for child sex and child BMIz. At 7 y, 116 boys and 118 girls were classified as having overweight/obesity, and these children had higher leptin levels. Cross-sectional analyses using the 7 y data produced the strongest results. Higher leptin at 7 y was significantly associated with lower scores on Satiety Responsiveness, Food Fussiness and Slowness in Eating, and higher scores on Food Responsiveness, Enjoyment of Food and Emotional Overeating at 7 y. Only the association with Emotional Overeating remained when adjusting for child BMIz. Significant interaction effects between child sex and leptin were found for appetite at 7 y, such that higher leptin was associated with higher Food Responsiveness (p < 0.001) and lower Slowness in Eating (p < 0.001) to a greater extent among boys. Umbilical cord blood leptin was not associated with appetitive behaviors at 7 or 10 y. Our results show that leptin levels are positively associated with food approach and negatively with food avoidant behaviors. Associations were more consistent in cross-sectional analyses (at 7 y), were largely dependent on child weight, and tended to be stronger among boys. Our findings support a role for leptin in affecting appetite, with potential consequences for current weight status and future weight gain.

Fibroblast Growth Factor 21 and the Adaptive Response to Nutritional Challenges

The Fibroblast Growth Factor 21 (FGF21) is considered an attractive therapeutic target for obesity and obesity-related disorders due to its beneficial effects in lipid and carbohydrate metabolism. FGF21 response is essential under stressful conditions and its metabolic effects depend on the inducer factor or stress condition. FGF21 seems to be the key signal which communicates and coordinates the metabolic response to reverse different nutritional stresses and restores the metabolic homeostasis. This review is focused on describing individually the FGF21-dependent metabolic response activated by some of the most common nutritional challenges, the signal pathways triggering this response, and the impact of this response on global homeostasis. We consider that this is essential knowledge to identify the potential role of FGF21 in the onset and progression of some of the most prevalent metabolic pathologies and to understand the potential of FGF21 as a target for these diseases. After this review, we conclude that more research is needed to understand the mechanisms underlying the role of FGF21 in macronutrient preference and food intake behavior, but also in β-klotho regulation and the activity of the fibroblast activation protein (FAP) to uncover its therapeutic potential as a way to increase the FGF21 signaling.

Single-Arm 8-Week Ad Libitum Self-Prepared Paleo Diet Reduces Cardiometabolic Disease Risk Factors in Overweight Adults

The paleo diet is popular among the general population due to promoted weight loss and disease prevention benefits. We examined the effectiveness of a self-administered paleo diet in improving cardiometabolic disease risk factors. Overweight, physically inactive but otherwise healthy adults (males = 4, females = 3, age 32.7 ± 4.9 years, body mass index [BMI] 29.4 ± 2.4 kg/m²) habitually eating a traditional Western diet (1853.4 ± 441.2 kcal; 34.0% carbohydrate; 41.4% fat; 19.2% protein) completed an ad libitum self-administered paleo diet for 8 weeks. Height, weight, blood pressure, and a fasting blood sample were collected pre- and post-paleo dietary intervention. Blood samples were analyzed for fasting cardiometabolic disease biomarkers-including brain-derived neurotropic factor (BDNF), fibroblast growth factor (FGF) 21, and leptin. After 8 weeks, body mass (-5.3 kg, P = .008), BMI (-1.7 kg/m², P = .002), serum leptin (-56.2%, P = .012), serum FGF21 (-26.7%, P = .002), and serum BDNF (-25.8%, P = .045) significantly decreased. Systolic and diastolic blood pressure were unchanged following the paleo dietary intervention (P > .05). Average energy intake (-412.6 kcal, P = .016) significantly decreased with the paleo dietary intervention mostly due to a reduction in carbohydrate consumption (-69.2 g; P = .003). An 8-week self-administered paleo dietary intervention was effective in improving cardiometabolic disease risk factors in a healthy, physically inactive overweight adult population.

Changes in eating behavior and plasma leptin in children with obesity participating in a family-centered lifestyle intervention

The goal of childhood obesity lifestyle interventions are to positively change body composition, however it is unknown if interventions also modulate factors that are related to energy intake. This study aimed to examine changes in eating behaviors and plasma leptin concentrations in overweight and obese children participating in a 1-year family-centered lifestyle intervention. Interventions were based on Canadian diet and physical activity (PA) guidelines. Children were randomized to 1 of 3 groups: Control (Ctrl; no intervention), Standard treatment (StnTx: 2 servings milk and alternatives/day (d), 3x/wk weight-bearing PA), or Modified treatment (ModTx: 4 servings milk and alternatives/day; daily weight-bearing PA). Study visits occurred every 3-months for 1-y; interventions were held once a month for 6-months with one follow-up visit at 8-months. Ctrl received counselling after 1-y. Caregivers completed the Children's Eating Behavior Questionnaire (CEBQ) and reported on diet and activity. Plasma leptin were measured from morning fasted blood samples. Seventy-eight children (mean age 7.8 ± 0.8 y; mean BMI 24.4 ± 3.3 kg/m²) participated; 94% completed the study. Compared to baseline, at 6-months StnTx reduced Emotional Overeating and Desire to Drink scores (p < 0.05) while Food Responsiveness scores were reduced in both StnTx and ModTx (p < 0.05). At 1-year, scores for Desire to Drink in StnTx remained reduced compared to baseline (p < 0.05). Plasma leptin concentrations were significantly lower in ModTx at 6-months compared to baseline (p < 0.05). This study resulted in intervention groups favorably changing eating behaviors, supporting the use family-centered lifestyle interventions using Canadian diet and PA recommendations for children with obesity.

Searching for Evidence of an Anti-Inflammatory Diet in Children: A Systematic Review of Randomized Controlled Trials for Pediatric Obesity Interventions With a Focus on Leptin, Ghrelin, and Adiponectin

PROBLEM

To address the complex phenomenon of pediatric obesity, one must understand the physiological mechanisms regulating energy intake and inflammation. The peptide hormones leptin, ghrelin, and adiponectin are involved in both, but their functions are dysregulated in obesity. The purpose of this systematic review is (1) to characterize studies of nutrition interventions for weight management in children who measure these peptides as outcomes, (2) to assess risk of bias in the studies, and (3) to determine the relationships between these peptides and body mass index (BMI). Eligibility Criteria: Peer-reviewed articles written in English, published in 2001-2016, and describing randomized controlled trials of pediatric interventions involving a nutrition component with the outcome measures leptin, ghrelin, and/or adiponectin were included. Articles were excluded if the intervention involved pharmaceuticals, supplements, infant formula, breastfeeding, or surgery.

SAMPLE

The 25 international studies represented 2,153 obese children.

RESULTS

Ten diets were identified. Successful interventions included both structured exercise and hypocaloric dietary components, with or without counseling, resistance training, or medical components. Direct measures of adiposity were used in 69% of studies. Comparison group designs were disparate. Leptin levels decreased as BMI decreased. Evidence regarding the relationships of ghrelin and adiponectin with BMI was inconclusive.

CONCLUSIONS

Despite known effects of maturation on hormones, studies did not consistently differentiate findings by maturational stage. Common anti-inflammatory and disease risk modification diets were missing or underrepresented. Studies that include children with comorbidities are needed. BMI and leptin levels have a positive relationship, but evidence on ghrelin and adiponectin was inconclusive.

Hepatic, adipocyte, enteric and pancreatic hormones: response to dietary macronutrient composition and relationship with metabolism

Background

We sought to characterize the effects of dietary macronutrient composition on various hormones implicated in the regulation of insulin sensitivity (IS) and energy expenditure (EE).

Methods

Following 10–15% weight loss, 21 overweight subjects consumed 3 weight-loss maintenance diets [low fat (LF), low glycemic index (LGI) and very low carbohydrate (VLC)] in random order, each for 4 weeks. At baseline and at the end of each treatment period, fasting samples for fibroblast growth factor (FGF)-21, heme-oxygenase-1 (HO-1), chemerin, irisin, secreted frizzle-related protein (SFRP-4), total bile acids, ghrelin, gastrin inhibitory peptide (GIP), peptide-Y, and amylin; hepatic and peripheral IS; and EE were obtained. Analyses were controlled for age, gender, baseline body mass index, and diet sequence.

Results

FGF-21 decreased (P < 0.0001), with differential effect by macronutrient composition (mean change from baseline ± SEM: LF −49.4 ± 16.6, LGI -58.6 ± 16.3, VLC -76.7 ± 18.2 pg/mL, P = 0.0002). Change in FGF-21 was inversely associated with change in hepatic IS [Beta = −0.565 units/log(ng/mL), P = 0.02], but not with peripheral IS or EE. Heme-oxygenase-1 (HO-1) increased (P = 0.003), without differential effect by macronutrient composition (LF 0.40 ± 0.26, LGI 0.98 ± 0.63, VLC 0.49 ± 0.29 ng/mL, P = 0.07). Ghrelin increased (P = 0.0003), while chemerin decreased (P = 0.001) without macronutrient effect. Total bile acid, irisin, SFRP-4, GIP, peptide-Y and amylin levels did not change.

Conclusions

FGF-21 levels decreased with dietary intervention in proportion to carbohydrate content, and correlated with hepatic insulin sensitivity, suggesting a pattern of improving FGF-21 resistance. HO-1 increased in response to dietary intervention, a tendency to greater increase in response to the LGI diet. Dietary intervention affected ghrelin and chemerin, independent of macronutrient composition. These findings may elucidate relationships between dietary composition, insulin sensitivity and metabolism.

Trial registration

NCT00315354.

Diet, physical activity and behavioural interventions for the treatment of overweight or obese children from the age of 6 to 11 years

BACKGROUND

Child and adolescent overweight and obesity has increased globally, and can be associated with significant short- and long-term health consequences. This is an update of a Cochrane review published first in 2003, and updated previously in 2009. However, the update has now been split into six reviews addressing different childhood obesity treatments at different ages.

OBJECTIVES

To assess the effects of diet, physical activity and behavioural interventions (behaviour-changing interventions) for the treatment of overweight or obese children aged 6 to 11 years.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, LILACS as well as trial registers ClinicalTrials.gov and ICTRP Search Portal. We checked references of studies and systematic reviews. We did not apply any language restrictions. The date of the last search was July 2016 for all databases.

SELECTION CRITERIA

We selected randomised controlled trials (RCTs) of diet, physical activity, and behavioural interventions (behaviour-changing interventions) for treating overweight or obese children aged 6 to 11 years, with a minimum of six months' follow-up. We excluded interventions that specifically dealt with the treatment of eating disorders or type 2 diabetes, or included participants with a secondary or syndromic cause of obesity.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened references, extracted data, assessed risk of bias, and evaluated the quality of the evidence using the GRADE instrument. We contacted study authors for additional information. We carried out meta-analyses according to the statistical guidelines in the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

We included 70 RCTs with a total of 8461 participants randomised to either the intervention or control groups. The number of participants per trial ranged from 16 to 686. Fifty-five trials compared a behaviour-changing intervention with no treatment/usual care control and 15 evaluated the effectiveness of adding an additional component to a behaviour-changing intervention. Sixty-four trials were parallel RCTs, and four were cluster RCTs. Sixty-four trials were multicomponent, two were diet only and four were physical activity only interventions. Ten trials had more than two arms. The overall quality of the evidence was low or very low and 62 trials had a high risk of bias for at least one criterion. Total duration of trials ranged from six months to three years. The median age of participants was 10 years old and the median BMI z score was 2.2.Primary analyses demonstrated that behaviour-changing interventions compared to no treatment/usual care control at longest follow-up reduced BMI, BMI z score and weight. Mean difference (MD) in BMI was -0.53 kg/m2 (95% confidence interval (CI) -0.82 to -0.24); P < 0.00001; 24 trials; 2785 participants; low-quality evidence. MD in BMI z score was -0.06 units (95% CI -0.10 to -0.02); P = 0.001; 37 trials; 4019 participants; low-quality evidence and MD in weight was -1.45 kg (95% CI -1.88 to -1.02); P < 0.00001; 17 trials; 1774 participants; low-quality evidence.Thirty-one trials reported on serious adverse events, with 29 trials reporting zero occurrences RR 0.57 (95% CI 0.17 to 1.93); P = 0.37; 4/2105 participants in the behaviour-changing intervention groups compared with 7/1991 participants in the comparator groups). Few trials reported health-related quality of life or behaviour change outcomes, and none of the analyses demonstrated a substantial difference in these outcomes between intervention and control. In two trials reporting on minutes per day of TV viewing, a small reduction of 6.6 minutes per day (95% CI -12.88 to -0.31), P = 0.04; 2 trials; 55 participants) was found in favour of the intervention. No trials reported on all-cause mortality, morbidity or socioeconomic effects, and few trials reported on participant views; none of which could be meta-analysed.As the meta-analyses revealed substantial heterogeneity, we conducted subgroup analyses to examine the impact of type of comparator, type of intervention, risk of attrition bias, setting, duration of post-intervention follow-up period, parental involvement and baseline BMI z score. No subgroup effects were shown for any of the subgroups on any of the outcomes. Some data indicated that a reduction in BMI immediately post-intervention was no longer evident at follow-up at less than six months, which has to be investigated in further trials.

AUTHORS' CONCLUSIONS

Multi-component behaviour-changing interventions that incorporate diet, physical activity and behaviour change may be beneficial in achieving small, short-term reductions in BMI, BMI z score and weight in children aged 6 to 11 years. The evidence suggests a very low occurrence of adverse events. The quality of the evidence was low or very low. The heterogeneity observed across all outcomes was not explained by subgrouping. Further research is required of behaviour-changing interventions in lower income countries and in children from different ethnic groups; also on the impact of behaviour-changing interventions on health-related quality of life and comorbidities. The sustainability of reduction in BMI/BMI z score and weight is a key consideration and there is a need for longer-term follow-up and further research on the most appropriate forms of post-intervention maintenance in order to ensure intervention benefits are sustained over the longer term.