scholarly journals Does Regular Exercise without Weight Loss Reduce Insulin Resistance in Children and Adolescents?

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
YoonMyung Kim ◽  
HaNui Park
Keyword(s):  
Insulin Resistance ◽  
Weight Loss ◽  
Childhood Obesity ◽  
Insulin Sensitivity ◽  
Exercise Training ◽  
Calorie Restriction ◽  
Pediatric Population ◽  
Optimal Dose ◽  
Regular Exercise ◽  
Type Of Exercise

Despite considerable efforts to tackle childhood obesity, it is recognized as one of the biggest health problems globally. Childhood obesity is a leading cause of many comorbid conditions such as metabolic syndrome and insulin resistance as well as type 2 diabetes. A strong body of evidence suggests that regular exercise without calorie restriction or weight loss is associated with reduced insulin resistance as well as improved insulin sensitivity in overweight and obese adults. However, despite the well-known benefits associated with regular exercise alone, the independent role of exercise training without calorie restriction on insulin resistance is still uncertain in youth. Some studies observed that both the aerobic and resistance type of exercise training without calorie restriction resulted in meaningful changes in insulin sensitivity, suggesting that exercise alone is an effective therapeutic strategy for reducing insulin resistance in overweight and obese youth. However, only few studies are available on the optimal dose of exercise training without calorie restriction or preferred exercise modality for reducing insulin resistance, which warrants further investigations in the pediatric population.

scholarly journals Enhanced cortisol production rates, free cortisol, and 11β-HSD-1 expression correlate with visceral fat and insulin resistance in men: effect of weight loss

2009 ◽  
Vol 296 (2) ◽  
pp. E351-E357 ◽  
Author(s):  
Jonathan Q. Purnell ◽  
Steven E. Kahn ◽  
Mary H. Samuels ◽  
David Brandon ◽  
D. Lynn Loriaux ◽  
...  
Keyword(s):  
Gene Expression ◽  
Insulin Resistance ◽  
Weight Loss ◽  
Insulin Sensitivity ◽  
Visceral Fat ◽  
Abdominal Fat ◽  
Metabolic Clearance ◽  
Clearance Rates ◽  
Production Rates ◽  
Free Cortisol

Controversy exists as to whether endogenous cortisol production is associated with visceral obesity and insulin resistance in humans. We therefore quantified cortisol production and clearance rates, abdominal fat depots, insulin sensitivity, and adipocyte gene expression in a cohort of 24 men. To test whether the relationships found are a consequence rather than a cause of obesity, eight men from this larger group were studied before and after weight loss. Daily cortisol production rates (CPR), free cortisol levels (FC), and metabolic clearance rates (MCR) were measured by stable isotope methodology and 24-h sampling; intra-abdominal fat (IAF) and subcutaneous fat (SQF) by computed tomography; insulin sensitivity (SI) by frequently sampled intravenous glucose tolerance test; and adipocyte 11β-hydroxysteroid dehydrogenase-1 (11β-HSD-1) gene expression by quantitative RT-PCR from subcutaneous biopsies. Increased CPR and FC correlated with increased IAF, but not SQF, and with decreased SI. Increased 11β-HSD-1 gene expression correlated with both IAF and SQF and with decreased SI. With weight loss, CPR, FC, and MCR did not change compared with baseline; however, with greater loss in body fat than lean mass during weight loss, both CPR and FC increased proportionally to final fat mass and IAF and 11β-HSD-1 decreased compared with baseline. These data support a model in which increased hypothalamic-pituitary-adrenal activity in men promotes selective visceral fat accumulation and insulin resistance and may promote weight regain after diet-induced weight loss, whereas 11β-HSD-1 gene expression in SQF is a consequence rather than cause of adiposity.

scholarly journals 3068 Effects of exercise and a very low fat diet in metabolically abnormal obese adults

2019 ◽  
Vol 3 (s1) ◽  
pp. 40-40
Author(s):  
George Schweitzer ◽  
Monica Kearney ◽  
Gordon Smith ◽  
Samuel Klein
Keyword(s):  
Weight Loss ◽  
Insulin Sensitivity ◽  
Exercise Training ◽  
Comparative Trial ◽  
Left Ventricular Diastolic Function ◽  
Postprandial Glucose ◽  
Left Ventricular ◽  
Low Fat ◽  
Glucose Response ◽  
Skeletal Muscle Insulin Sensitivity

OBJECTIVES/SPECIFIC AIMS: People with metabolically abnormal obesity (MAO), defined as those with insulin resistance and high intrahepatic triglyceride, are at high risk for developing type 2 diabetes and cardiovascular disease. Weight loss through reduced energy intake and increased physical activity has profound impacts on improving cardiometabolic function. However, the specific additional effects of exercise training with diet-induced weight loss on metabolic function are equivocal. METHODS/STUDY POPULATION: A comparative trial is ongoing in MAO adults undergoing 8-10% weight loss induced by a very-low fat plant-based (PB) diet with structured exercise training (n=8) compared to the same weight loss induced by the PB diet alone (n=3). RESULTS/ANTICIPATED RESULTS: Preliminary results indicate that, PB diet with or without exercise training results in significant weight loss concomitant with enhanced insulin sensitivity, reduced intrahepatic triglyceride, reduced 24-hour postprandial glucose response, reduced fat mass, and reduced diastolic blood pressure. Those undergoing PB diet with exercise training had greater improvements in muscular strength and cardiorespiratory fitness than those undergoing PB diet alone. Differences between intervention groups for other cardiometabolic measures are not yet known. DISCUSSION/SIGNIFICANCE OF IMPACT: Each of the interventions resulted in improved cardiometabolic measures; however the extent of the differences between the interventions is not yet clear. It is hypothesized that compared with weight loss induced by a PB diet, the same weight loss induced by a PB diet and structured exercise training will i) cause greater improvement in skeletal muscle insulin sensitivity, ii) will attenuate the usual decline in muscle mass while increasing strength, and iii) result in greater increases in left ventricular diastolic function. The long-term objective of this proposal is to provide a foundation for future studies evaluating mechanisms for the effects of exercise in cardiometabolic disease prevention and therapy.

scholarly journals The Relationship between Circulating Acetate and Human Insulin Resistance before and after Weight Loss in the DiOGenes Study

Nutrients ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 339
Author(s):  
Manuel A. González Hernández ◽  
Emanuel E. Canfora ◽  
Kenneth Pasmans ◽  
A. Astrup ◽  
W. H. M. Saris ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Weight Loss ◽  
Insulin Sensitivity ◽  
Positive Association ◽  
Fat Free Mass ◽  
Model Assessment ◽  
Random Factor ◽  
Before And After ◽  
Homeostatic Model Assessment ◽  
Matsuda Index

Microbially-produced acetate has been reported to beneficially affect metabolic health through effects on satiety, energy expenditure, insulin sensitivity, and substrate utilization. Here, we investigate the association between sex-specific concentrations of acetate and insulin sensitivity/resistance indices (Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), circulating insulin and Matsuda Index) in the Diet, Obesity and Genes (DiOGenes) Dietary study at baseline and after a low-calorie diet (LCD, 800 kcal/d). In this analysis, 692 subjects (Body Mass Index >27 kg/m2) were included, who underwent an LCD for 8 weeks. Linear mixed models were performed, which were adjusted for mean acetate concentration, center (random factor), age, weight loss, and fat-free mass (FFM). At baseline, no associations between plasma acetate and insulin sensitivity/resistance indices were found. We found a slight positive association between changes in acetate and changes in HOMA-IR (stdβ 0.130, p = 0.033) in women, but not in men (stdβ −0.072, p = 0.310) independently of age, weight loss and FFM. We were not able to confirm previously reported associations between acetate and insulin sensitivity in this large European cohort. The mechanisms behind the sex-specific relationship between LCD-induced changes in acetate and insulin sensitivity require further study.

scholarly journals The effect of intermittent energy and carbohydrate restrictionv. daily energy restriction on weight loss and metabolic disease risk markers in overweight women

2013 ◽  
Vol 110 (8) ◽  
pp. 1534-1547 ◽  
Author(s):  
Michelle Harvie ◽  
Claire Wright ◽  
Mary Pegington ◽  
Debbie McMullan ◽  
Ellen Mitchell ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Weight Loss ◽  
Insulin Sensitivity ◽  
Body Fat ◽  
Disease Risk ◽  
Phase 1 ◽  
Weight Maintenance ◽  
Energy Restriction ◽  
Overweight Women ◽  
Daily Energy

Intermittent energy restriction may result in greater improvements in insulin sensitivity and weight control than daily energy restriction (DER). We tested two intermittent energy and carbohydrate restriction (IECR) regimens, including one which allowedad libitumprotein and fat (IECR+PF). Overweight women (n115) aged 20 and 69 years with a family history of breast cancer were randomised to an overall 25 % energy restriction, either as an IECR (2500–2717 kJ/d, < 40 g carbohydrate/d for 2 d/week) or a 25 % DER (approximately 6000 kJ/d for 7 d/week) or an IECR+PF for a 3-month weight-loss period and 1 month of weight maintenance (IECR or IECR+PF for 1 d/week). Insulin resistance reduced with the IECR diets (mean − 0·34 (95 % CI − 0·66, − 0·02) units) and the IECR+PF diet (mean − 0·38 (95 % CI − 0·75, − 0·01) units). Reductions with the IECR diets were significantly greater compared with the DER diet (mean 0·2 (95 % CI − 0·19, 0·66) μU/unit,P= 0·02). Both IECR groups had greater reductions in body fat compared with the DER group (IECR: mean − 3·7 (95 % CI − 2·5, − 4·9) kg,P= 0·007; IECR+PF: mean − 3·7 (95 % CI − 2·8, − 4·7) kg,P= 0·019; DER: mean − 2·0 (95 % CI − 1·0, 3·0) kg). During the weight maintenance phase, 1 d of IECR or IECR+PF per week maintained the reductions in insulin resistance and weight. In the short term, IECR is superior to DER with respect to improved insulin sensitivity and body fat reduction. Longer-term studies into the safety and effectiveness of IECR diets are warranted.

scholarly journals Changes Induced by Physical Activity and Weight Loss in the Morphology of Intermyofibrillar Mitochondria in Obese Men and Women

2006 ◽  
Vol 91 (8) ◽  
pp. 3224-3227 ◽  
Author(s):  
Frederico G. S. Toledo ◽  
Simon Watkins ◽  
David E. Kelley
Keyword(s):  
Physical Activity ◽  
Insulin Resistance ◽  
Skeletal Muscle ◽  
Weight Loss ◽  
Insulin Sensitivity ◽  
Lifestyle Modification ◽  
Vastus Lateralis ◽  
Vastus Lateralis Muscle ◽  
Mitochondrial Content ◽  
The Mean

Abstract Context: In obesity, skeletal muscle insulin resistance may be associated with smaller mitochondria. Objective: Our objective was to examine the effect of a lifestyle-modification intervention on the content and morphology of skeletal muscle mitochondria and its relationship to insulin sensitivity in obese, insulin-resistant subjects. Design: In this prospective interventional study, intermyofibrillar mitochondrial content and size were quantified by transmission electron microscopy with quantitative morphometric analysis of biopsy samples from vastus lateralis muscle. Systemic insulin sensitivity was measured with euglycemic hyperinsulinemic clamps. Setting: The study took place at a university-based clinical research center. Participants: Eleven sedentary, overweight/obese volunteers without diabetes participated in the study. Intervention: Intervention included 16 wk of aerobic training with dietary restriction of 500-1000 kcal/d. Main Outcome Measures: We assessed changes in mitochondrial content and size and changes in insulin sensitivity. Results: The percentage of myofiber volume occupied by mitochondria significantly increased from 3.70 ± 0.31 to 4.87 ± 0.33% after intervention (P = 0.01). The mean individual increase was 42.5 ± 18.1%. There was also a change in the mean cross-sectional mitochondrial area, increasing from a baseline of 0.078 ± 0.007 to 0.091 ± 0.007 μm2 (P &lt; 0.01), a mean increase of 19.2 ± 6.1% per subject. These changes in mitochondrial size and content highly correlated with improvements in insulin resistance (r = 0.68 and 0.72, respectively; P = 0.01). Conclusions: A combined intervention of weight loss and physical activity in previously sedentary obese adults is associated with enlargement of mitochondria and an increase in the mitochondrial content in skeletal muscle. These findings indicate that in obesity with insulin resistance, ultrastructural mitochondrial plasticity is substantially retained and, importantly, that changes in the morphology of mitochondria are associated with improvements in insulin resistance.

scholarly journals Effect of Exercise Training on Fat Loss—Energetic Perspectives and the Role of Improved Adipose Tissue Function and Body Fat Distribution

2021 ◽  
Vol 12 ◽  
Author(s):  
Kristoffer Jensen Kolnes ◽  
Maria Houborg Petersen ◽  
Teodor Lien-Iversen ◽  
Kurt Højlund ◽  
Jørgen Jensen
Keyword(s):  
Physical Activity ◽  
Weight Loss ◽  
Adipose Tissue ◽  
Insulin Sensitivity ◽  
Exercise Training ◽  
Cardiorespiratory Fitness ◽  
Body Fat ◽  
Interval Training ◽  
Fat Distribution ◽  
Abdominal Fat

In obesity, excessive abdominal fat, especially the accumulation of visceral adipose tissue (VAT), increases the risk of metabolic disorders, such as type 2 diabetes mellitus (T2DM), cardiovascular disease, and non-alcoholic fatty liver disease. Excessive abdominal fat is associated with adipose tissue dysfunction, leading to systemic low-grade inflammation, fat overflow, ectopic lipid deposition, and reduced insulin sensitivity. Physical activity is recommended for primary prevention and treatment of obesity, T2DM, and related disorders. Achieving a stable reduction in body weight with exercise training alone has not shown promising effects on a population level. Because fat has a high energy content, a large amount of exercise training is required to achieve weight loss. However, even when there is no weight loss, exercise training is an effective method of improving body composition (increased muscle mass and reduced fat) as well as increasing insulin sensitivity and cardiorespiratory fitness. Compared with traditional low-to-moderate-intensity continuous endurance training, high-intensity interval training (HIIT) and sprint interval training (SIT) are more time-efficient as exercise regimens and produce comparable results in reducing total fat mass, as well as improving cardiorespiratory fitness and insulin sensitivity. During high-intensity exercise, carbohydrates are the main source of energy, whereas, with low-intensity exercise, fat becomes the predominant energy source. These observations imply that HIIT and SIT can reduce fat mass during bouts of exercise despite being associated with lower levels of fat oxidation. In this review, we explore the effects of different types of exercise training on energy expenditure and substrate oxidation during physical activity, and discuss the potential effects of exercise training on adipose tissue function and body fat distribution.

Insulin sensitivity improvement with exercise training is mediated by body weight loss in subjects with metabolic syndrome

2020 ◽  
Vol 46 (3) ◽  
pp. 210-218 ◽  
Author(s):  
R. Mora-Rodriguez ◽  
J.F. Ortega ◽  
M. Ramirez-Jimenez ◽  
A. Moreno-Cabañas ◽  
F. Morales-Palomo
Keyword(s):  
Metabolic Syndrome ◽  
Weight Loss ◽  
Body Weight ◽  
Insulin Sensitivity ◽  
Exercise Training ◽  
Body Weight Loss ◽  
Sensitivity Improvement
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