Hypocaloric Dietary Intervention Research Articles

Ability of Hypocaloric Diets to Change Nutrient–Phyla Associations after 8 Weeks of Intervention

Background: Previous studies have suggested that changes in the composition of intestinal microbiota may be influenced by dietary quality. Objective: This study aimed to assess the impact of a hypocaloric diet on the relationship between microbiota and clinical/dietary variables. Methods: This was a longitudinal study. Ten women with obesity (Obese Group, ObG) participated in an 8-week home-based hypocaloric diet intervention. Anthropometric, dietary intake, biochemical, and gut microbiota assessments were conducted before and after the intervention. Microbiota relative abundance was determined using real-time PCR in triplicate. Results: In the ObG, the hypocaloric diet intervention led to significant weight loss (before: 119.5 ± 10.3 kg; after: 114.9 ± 10.2 kg; p = 0.003). Following the intervention, positive correlations were observed between nutrient intake and phyla composition: Actinobacteria phylum with fibers (r = 0.787; p = 0.012), Firmicutes phylum with proteins (r = 0.736; p = 0.024), and Proteobacteria phylum with lipids (r = 0.669; p = 0.049). Conclusions: The hypocaloric diet intervention improved health parameters associated with obesity and its comorbidities, demonstrating associations between nutrient intake and specific phyla.

Impact of a hypocaloric dietary intervention on antral follicle dynamics in eumenorrheic women with obesity.

Do antral follicle dynamics change in women with obesity and regular ovulatory cycles after a 6-month hypocaloric dietary intervention? After a 6-month hypocaloric dietary intervention, women with obesity and regular ovulatory cycles displayed evidence of improved antral follicle dynamics defined by the emergence of more dominant follicles, larger ovulatory follicle diameter at selection, and increased luteal progesterone concentrations compared to pre-intervention. Precise events in antral folliculogenesis must occur in order for natural and regular monthly ovulation. In healthy women of reproductive age, antral follicles are recruited for growth in a wave-like fashion, wherein a subset of follicles are selected for preferential growth, and typically, one dominant follicle culminates in ovulation. Women with obesity and regular ovulatory cycles display evidence of suppressed antral follicle development, as evidenced by fewer recruitment events, fewer selectable and dominant follicles, smaller diameter of the ovulatory follicle at selection, and a higher prevalence of luteal phase defects. While improvements in gonadotropin and ovarian steroid hormone concentrations after weight loss have been documented in eumenorrheic women with obesity, the precise impact of weight loss on antral follicle dynamics has not been evaluated. A pre-post pilot study of 12 women who participated in a 6-month hypocaloric dietary intervention. Twelve women with obesity (total body fat ≥35%) underwent transvaginal ultrasonography and venipuncture every-other-day for one inter-ovulatory interval (IOI) both before (baseline) and during the final month (Month 7) of a six-month hypocaloric dietary intervention. Participants were aged 24-34 years and had a self-reported history of regular menstrual cycles (25-35 days). Follicle number and diameter (≥2 mm) were quantified at each study visit, and individual growth profiles for all follicles ≥7 mm were determined. Blood samples were assayed for reproductive hormones. Follicle dynamics and reproductive hormone concentrations were compared pre- and post-intervention. Further, post-intervention follicle and endocrine dynamics (Month 7 IOI) were compared to an age-matched reference cohort of lean women with regular ovulatory cycles (total body fat <35%, N = 21). Participants lost an average of 11% of their original body weight with the hypocaloric dietary intervention. More dominant follicles were detected (≥10 mm) at Month 7 compared to baseline (0. 3 ± 0.4 versus 0.4 ± 0.5 follicles, P = 0.001), and ovulatory follicles were selected at larger diameters post-intervention (7.3 ± 2.0 versus 10.9 ± 2.6 mm, P = 0.007). Luteal progesterone concentrations were increased at Month 7 compared to baseline (5.3 ± 3.65 versus 6.3 ± 4.74 ng/ml, P < 0.0001). However, risk for luteal phase dysfunction as judged by the prevalence of a luteal phase length <10 days, integrated luteal progesterone levels <80 ng/ml or peak progesterone <10 ng/ml did not differ pre- versus post-intervention (all, P > 0.05). In Month 7, follicle dynamics and endocrine profiles were similar to the reference cohort across all measures. This study does not inform on the earliest stages of ovarian follicle development and is limited to providing knowledge on the later stages of antral follicle development. This study cannot fully address causation between weight loss and sustained improvements in antral follicle dynamics. The data cannot be extrapolated to comment on potential improvements in fertility and fecundity with weight loss. The small group sizes limit statistical power. The increasing prevalence of obesity necessitates an understanding of the mechanisms that underlie potential improvements in reproductive health outcomes with weight loss. Women with obesity and regular ovulatory cycles who undertook a 6-month hypocaloric dietary intervention demonstrated improvements consistent with benefits of lifestyle intervention on reproductive health even in those without overt signs of reproductive dysfunction. Potential improvements in the cellular makeup of follicles, which may underlie the restoration of normal follicle development and amelioration of subfertility, require further investigation. Cornell University, President's Council of Cornell Women, United States Department of Agriculture (Grant No. 8106), and National Institutes of Health (R01-HD0937848). B.Y.J. and H.V.B. were supported by doctoral training awards from the National Institutes of Health (T32-DK007158) and Canadian Institutes of Health Research (Grant No. 146182), respectively. The authors have no competing interests. NCT01927432 and NCT01785719.

FRI427 Hypocaloric Dietary Intervention Reduces Excessive Follicle Recruitment In Women With PCOS

Abstract Disclosure: F. Carter: None. N. Lee: None. A. Reich: None. B.Y. Jarrett: None. H. Vanden Brink: None. A. Oldfield: None. M.E. Lujan: None. Introduction: Disordered antral follicle development in polycystic ovary syndrome (PCOS) is characterized by excessive recruitment, early or absence of follicle selection and decreased incidence of dominance and ovulation. Whether lifestyle interventions aimed at weight loss improve defects in antral folliculogenesis to promote ovulation in women with PCOS and comorbid obesity is unknown. Objective: To test the hypothesis that a hypocaloric dietary intervention improves antral follicle development in a subset of women with PCOS and obesity as evidenced by decreased recruitment, and increased selection, dominance, and ovulation. Methods: Preliminary analysis of women with PCOS and obesity (7 out of 20) who participated in a hypocaloric dietary intervention was conducted. The study protocol consisted of every-other-day visits to a clinical research center for ovarian ultrasonography and venipuncture over a 4-week baseline period (pre-intervention), followed by a 12-week commercial hypocaloric dietary meal plan intervention aimed at achieving 1-2 lbs of weight loss per week. Anthropometry, DEXA, hirsutism scoring, and oral glucose tolerance testing were conducted at baseline and during the final month of the intervention in the follicular phase. The number and diameter of all follicles ≥ 2 mm at each visit were recorded offline, and individual follicles ≥ 7 mm were tracked using the Identity Method throughout the 16-weeks. Clinical, morphologic, and endocrine markers were compared using paired t-tests pre- vs. post-intervention, and linear mixed models assessed changes in recruitment, selection, dominance, and ovulation. Results: The hypocaloric dietary intervention resulted in mean weight loss of 8.8 ± 2.9% and significant reductions in waist (-13 ± 9 cm) and hips (-10 ± 3 cm) circumference, body mass index (-3.4 ± 1.4 kg/m2), and percent total body fat (-1.5 ± 1.3%; all p&amp;lt;0.02). Glucoregulatory status, menstrual cycle lengths, reproductive hormone (LH, FSH, E2, P4, TT, AMH) concentrations, and hirsutism scores did not differ pre- vs. post-intervention. The number of follicle recruitment events decreased with percent weight loss during the intervention (p=0.01), as did the average number of follicles recruited per cohort (p=0.01). By contrast, the frequency of follicle selection, dominance, and ovulation did not change with weight loss (p&amp;gt;0.05). Higher pre-intervention LH was associated with fewer follicles recruited per cohort during the intervention (p=0.03). No other metabolic or endocrine marker was correlated with changes in follicular events. Conclusion: Clinically meaningful weight loss induced by a hypocaloric dietary intervention resulted in improvements in early stages of antral follicle development in women with PCOS, albeit these changes did not affect ovulatory follicle dynamics or the frequency of ovulation Presentation: Friday, June 16, 2023

THU638 Comparison Of Body Composition Changes In Response To A Hypocaloric Dietary Intervention In Women With And Without Polycystic Ovary Syndrome

Abstract Disclosure: J. Zhang: None. F. Carter: None. B.Y. Jarrett: None. B. Drewes: None. H. Vanden Brink: None. M.E. Lujan: None. Lifestyle intervention aimed at weight loss is recommended for women with polycystic ovary syndrome (PCOS) and concurrent obesity to improve reproductive, metabolic, and psychological health and well-being. However, we and others have shown that women with PCOS have perceptions of reduced success of weight loss interventions, and futility related to adoption of healthy lifestyle practices which can affect motivation and adherence to lifestyle change. Empirical data to support reduced success of weight loss interventions in PCOS is lacking. The objective of this study was to contrast the effectiveness of a hypocaloric dietary intervention on weight loss and body composition in women with and without PCOS. Thirty-eight reproductive age females (body mass index ≥25) with (N=22) or without (N=16) PCOS partook in a 4-week baseline assessment (pre-intervention), followed by a 12-week (3MO, N=17) or 24-week (6MO, N=21) commercial hypocaloric dietary intervention. Serial weight assessments were conducted at least twice per week and dual x-ray absorptiometry (DEXA) measured body composition pre- and post-intervention. Random coefficient models were used to compare changes in weight during the intervention. Differences in body composition pre- and post-intervention and across groups were compared using linear regression and analysis of variance. Participants lost an average of 7.8±3.2% and 9.0±5.0% total body weight with the 3MO and 6MO interventions, respectively. Waist circumference (107.1 ± 14.0 vs. 96.9 ± 12.6cm, P&amp;lt;0.001), total lean mass (55.2 ± 7.2 vs. 51.8 ± 6.4cm, P&amp;lt;0.05), total fat mass (43.2 ± 9.7 vs. 38.8 ± 8.9cm, P&amp;lt;0.01) and trunk lean (27.1 ± 3.7 vs. 25.5 ± 3.6kg, P&amp;lt;0.05) and fat mass ((21.7 ± 5.7 vs. 19.6 ± 5.6kg, P&amp;lt;0.05) were decreased post-3MO intervention in women with PCOS, whereas only total (46.3 ± 8.2 vs. 39.4 ± 9.7kg, P&amp;lt;0.05) and trunk fat mass (23.3 ± 5.2 vs. 20.1 ± 6.0kg, P&amp;lt;0.05) were decreased post-6MO intervention in women with PCOS compared to their pre-intervention values. Percent changes in the aforementioned parameters were similar across groups with either the 3MO or 6MO intervention (P&amp;gt;0.05), as was the rate of weight loss (P&amp;gt;0.05). Women with PCOS demonstrated clinically meaningful changes in body composition in response to hypocaloric dietary interventions aimed at weight loss. Similar changes in body compositions and rate of weight loss between women with and without PCOS support comparable effectiveness of short-term hypocaloric dietary interventions in women with and without PCOS. Knowledge of comparable effectiveness to lifestyle change may aid in adoption and adherence to lifestyle interventions in women with PCOS. Presentation: Thursday, June 15, 2023

LBMON235 Impact Of A Hypocaloric Dietary Weight-loss Intervention On Antral Follicle Dynamics In Women With Obesity And Regular Ovulatory Cycles

Abstract We recently showed that eumenorrheic, ovulatory women with obesity experience suppressed antral follicle dynamics, as evidenced by fewer recruitment events, selectable follicles and dominant follicles. Ovulatory follicles were selected for preferential growth at smaller diameters and lower luteal progesterone production was also observed. Weight loss is posited to improve reproductive function in women with obesity. However, the mechanisms underlying these improvements are unclear. The objective of this study was to contrast ovarian follicular growth and endocrine dynamics in eumenorrheic women with obesity, before and after a weight-loss intervention. | Twelve reproductive age females with obesity (total percent body fat ≥35%) and regular menstrual cycles (21-35 days) were evaluated by serial ovarian transvaginal ultrasonography and venipuncture every-other-day for one complete inter-ovulatory interval (IOI) (pre-intervention) and after a 6-month hypocaloric dietary intervention (post-intervention). The number and diameters of all follicles ≥2mm at each visit were documented offline using the Grid Method. Growth profiles of individual follicles which grew to &amp;gt;7mm were recorded using the Identity Method to document antral follicle recruitment events, selection, and ovulation. Clinical, morphologic, and endocrine features were compared pre- and post-intervention using paired t-tests and mixed models. | Participants lost an average of 9.5±3.8% total body weight (IQR: 7.7-12.6%). Antral follicle counts (AFC) across the IOI were lower post-intervention versus pre-intervention (PINTERVENTION=0. 002), driven by fewer 2-5mm follicles (PINTERVENTION=0. 001). Participants tended to exhibit more recruitment events (Pre: 1. 0±0.7 vs. Post: 2. 0±0.9, P=0. 09) and more selectable (6-9mm) follicles before and after weight loss (4±3 vs. 6±4 respectively, P=0. 07). A greater number of selectable follicles achieved a diameter of &amp;gt;10mm across the IOI post-intervention (PINTERVENTION=0. 001). Ovulatory follicles were also selected at larger diameters after the intervention (Pre: 7.3±2.9mm vs. Post: 10.9±2.6, P=0. 01). Dominant and ovulatory follicle growth kinetics were similar before and after the intervention (All, P&amp;gt;0. 05). Luteal progesterone concentrations were higher in women after the intervention (Pre: 5.3±3.7 vs. Post: 6.3±4.7ng/mL, P&amp;lt;0. 0001). | Eumenorrheic women with obesity demonstrate changes in follicle dynamics with weight loss following a hypocaloric dietary intervention. Development of more dominant follicles, a larger diameter at selection, and increased luteal progesterone production suggests increased responsiveness to gonadotropins with weight loss. Further studies are needed to elucidate the metabolic mechanisms driving any transient or sustained changes in ovarian physiology with hypocaloric dietary interventions aimed at weight loss. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.

Effects Of A Lifestyle Intervention On Trimethylamine N-oxide (tmao) Concentrations In Overweight And Obese Adults

PURPOSE: Trimethylamine N-Oxide (TMAO), a metabolite produced by gut microbiota and flavin-containing monooxygenase-3 (FMO3) of the liver, is found in foods high in carnitine, choline, and lecithin (e.g., egg yolks and full-fat dairy). The oxidation of choline that leads to betaine production also contributes to increased TMAO levels. Epidemiological studies have related TMAO concentrations to obesity and cardiovascular disease, yet few data exist on the effects of combined diet and exercise interventions on TMAO. METHODS: Twenty-six sedentary, overweight or obese adults (Age: 47.4 ± 10.7 yrs.; Weight: 95.1 ± 13.1 kg; BMI: 34.1 ± 3.2 kg/m2) completed a 10-week exercise and hypocaloric diet intervention to obtain clinically significant weight loss of ≥7%. Aerobic exercise volume began at 300 MET min per week and increased 50 MET min weekly until 700 MET min per week was reached. For 8 weeks, the OPTIFAST program included full meal replacement (~800 daily kcal). The last 2 weeks participants could replace 2 products with whole foods and increase intake (~1400 daily kcal). Weekly classes on behavior modification were also offered. Plasma blood samples were collected at baseline and follow-up and analyzed via nuclear magnetic resonance. RESULTS: At baseline, TMAO correlated with body weight (r = 0.40, p = 0.046), waist circumference (r = 0.40, p = 0.044), and RMR (r = 0.50, p = 0.009). Waist circumference (-7.6 cm), BMI (-3.1 kg/m2), body weight (-8.5 kg, -9.0%), total body fat (-1.7%), and triglycerides (-31.7 mg/dL) (all ps < 0.001) decreased following the intervention, however, there were no changes in TMAO (-0.3 μM, p = 0.292) or betaine (0.3 μM, p = 0.838) levels. Changes in TMAO were correlated with waist circumference (r = 0.50, p = 0.010), but not with change in body weight, body composition (lean mass, visceral mass, total fat mass), fitness, or cardiometabolic risk factors (all ps > 0.05), while changes in betaine were correlated with average RMR changes (r = -0.42, p = 0.037). CONCLUSIONS: Weight loss from a hypocaloric diet with aerobic exercise did not decrease TMAO, however, improvements in TMAO were associated with reductions in waist circumferenc in previously sedentary overweight and obese adults. Future studies should evaluate predictors of changes in TMAO during weight maintenance.

Unsupervised Exercise Training Was Not Found to Improve the Metabolic Health or Phenotype over a 6-Month Dietary Intervention: A Randomised Controlled Trial with an Embedded Economic Analysis.

Ectopic fat leads to metabolic health problems. This research aimed to assess the effectiveness of a hypocaloric diet intervention together with an unsupervised exercise training program in comparison with a hypocaloric diet alone to reduce ectopic fat deposition. Sixty-one premenopausal women with overweight or obesity participated in this controlled trial and were each randomised into either a usual care group (hypocaloric diet) or intervention group (hypocaloric diet + unsupervised exercise training). Ectopic fat deposition, metabolic parameters, incremental costs from a societal perspective and incremental quality-adjusted life years (QALYs) were assessed before, during and after the six-month intervention period. In the total sample, there was a significant decrease in visceral adipose tissue (VAT: −18.88 cm2, 95% CI −11.82 to −25.95), subcutaneous abdominal adipose tissue (SAT: −46.74 cm2, 95% CI −29.76 to −63.18), epicardial fat (ECF: −14.50 cm3, 95% CI −10.9 to −18.98) and intrahepatic lipid content (IHL: −3.53%, 95% CI −1.72 to −5.32). Consequently, an “adapted” economic analysis revealed a non-significant decrease in costs and an increase in QALYs after the intervention. No significant differences were found between groups. A multidisciplinary lifestyle approach seems successful in reducing ectopic fat deposition and improving the metabolic risk profile in women with overweight and obesity. The addition of unsupervised exercise training did not further improve the metabolic health or phenotype over the six months.

Understanding the effects of nutrition and post-exercise nutrition on skeletal muscle protein turnover: Insights from stable isotope studies

Understanding the effects of nutrition and post-exercise nutrition on skeletal muscle protein turnover: Insights from stable isotope studies

DNA methylation pattern changes following a short-term hypocaloric diet in women with obesity.

We aimed to investigate the effects of short-term hypocaloric diet-induced weight loss on DNA methylation profile in leukocytes from women with severe obesity. Eleven women with morbid obesity (age: 36.9 ± 10.3 years; BMI: 58.5 ± 10.5 kg/m2) were assessed before and after 6 weeks of a hypocaloric dietary intervention. The participants were compared with women of average weight and the same age (age: 36.9 ± 11.8 years; BMI: 22.5 ± 1.6 kg/m2). Genome-wide DNA methylation analysis was performed in DNA extracted from peripheral blood leukocytes using the Infinium Human Methylation 450 BeadChip assay. Changes (Δβ) in the methylation level of each CpGs were calculated. A threshold with a minimum value of 10%, p < 0.001, for the significant CpG sites based on Δβ and a false discovery rate of <0.05 was set. Dietary intervention changed the methylation levels at 16,064 CpG sites. These CpGs sites were related to cancer, cell cycle-related, MAPK, Rap1, and Ras signaling pathways. However, regardless of hypocaloric intervention, a group of 878 CpGs (related to 649 genes) remained significantly altered in obese women when compared with normal-weight women. Pathway enrichment analysis identified genes related to the cadherin and Wnt pathway, angiogenesis signaling, and p53 pathways by glucose deprivation. A short-term hypocaloric intervention in patients with severe obesity partially restored the obesity-related DNA methylation pattern. Thus, the full change of obesity-related DNA methylation patterns could be proportional to the weight-loss rate in these patients after dietary interventions.

Moderate Weight Loss Modifies Leptin and Ghrelin Synthesis Rhythms but Not the Subjective Sensations of Appetite in Obesity Patients.

Obesity is characterized by a resistance to appetite-regulating hormones, leading to a misalignment between the physiological signals and the perceived hunger/satiety signal. A disruption of the synthesis rhythm may explain this situation. The aim of this study was to evaluate the effect of dietary-induced weight loss on the daily rhythms of leptin and ghrelin and its influence on the daily variability of the appetite sensations of patients with obesity. Twenty subjects with obesity underwent a hypocaloric dietary intervention for 12 weeks. Plasma leptin and ghrelin were analyzed at baseline and at the end of the intervention and in 13 normal-weight controls. Appetite ratings were analyzed. Weight loss decreased leptin synthesis (pauc < 0.001) but not the rhythm characteristics, except the mean variability value (pmesor = 0.020). By contrast, the mean ghrelin level increased after weight loss. The rhythm characteristics were also modified until a rhythm similar to the normal-weight subjects was reached. The amount of variability of leptin and ghrelin was correlated with the effectiveness of the dietary intervention (p < 0.020 and p < 0.001, respectively). Losing weight partially restores the daily rhythms of leptin and modifies the ghrelin rhythms, but appetite sensations are barely modified, thus confirming that these hormones cannot exercise their physiological function properly.

SUN-LB666: Do Longitudinal Epigenetics Changes After a 6-Weeks of Hypocaloric Dietary Intervention can Modulate Cancer Pathways?

SUN-LB666: Do Longitudinal Epigenetics Changes After a 6-Weeks of Hypocaloric Dietary Intervention can Modulate Cancer Pathways?

FTO rs9939609 A allele influences anthropometric outcome in response to dietary intervention, but not in response to physical exercise program.

The fat mass and obesity-associated (FTO) gene is involved in energy homeostasis. The A allele of the rs9939609 (SNP; T>A) is associated with obesity and higher food intake, while its effect in energy expenditure remains unclear. The aim of this study is to examine whether FTOrs9939609 is associated with the anthropometric outcomes of a physical exercise program and a dietary intervention. We studied two independent samples. The first was composed by children and adolescents in which overweight and obese individuals were submitted to a physical exercise program (n = 136) and normal weight participants served as a control group (n = 172). The second sample was composed by obese women submitted to a hypocaloric dietary intervention (n = 126). Physical exercise and dietary intervention were effective, independently of genotype. We found no association of FTO rs9939609 with obesity in children and adolescents (p = 0.67). The rs9939609 affected the response to dietary intervention in obese women: A allele carriers reduced 2.7cm less of abdominal circumference (AC) than homozygous TT (p = 0.04), while no effect was observed in response to physical exercise in overweight and obese children and adolescents. The A allele is associated with a worse outcome in response to the hypocaloric dietary intervention regarding abdominal circumference reduction; the same allele did not show interaction with any anthropometric outcomes in response to the exercise program applied.

Effects of dietary modification with weight loss on central blood pressure during oral glucose tolerance test in overweight/obese men

BackgroundPostprandial regulation of central systolic blood pressure (cSBP) is impaired by obesity-related disorders. The present study aimed to examine the effect of hypocaloric diet intervention on cSBP when performing oral glucose tolerance test (OGTT) in overweight/obese men and explore its mechanism. MethodsFifteen overweight/obese men (mean ± SD; age, 52 ± 10 years; BMI, 29.1 ± 2.3 kg/m2) completed a 12-week dietary modification program (group lectures and individual counseling conducted 8 times in 12 weeks, 1680 kcal/day). Before and after the program, body mass, daily intakes of total energy and major macronutrients, serum lipid profiles, and homeostasis model assessment for insulin resistance (HOMA-IR) were measured, and plasma glucose, serum insulin, and cSBP (i.e., radial second systolic pressure) were assessed when fasting and at 60 min and 120 min after 75 g oral glucose loading. ResultsThe 12-week program led to successful weight loss (−10.1 kg or −12.1%) with significant reductions in the daily intakes of total energy and major macronutrients. Consequently, low-density lipoprotein cholesterol, triglycerides, HOMA-IR (2.1 ± 1.3 to 0.8 ± 0.3, p < 0.01), and glucose and insulin during OGTT were substantially decreased after 12 weeks. The diet program had also resulted in significantly reduced 2-h averaged cSBP during OGTT (111 ± 11 to 103 ± 10 mmHg, p < 0.01). There was a significant correlation between the changes from baseline in both HOMA-IR and 2-h averaged cSBP (rs = 0.69, p < 0.01). ConclusionsThe current results suggest that the dietary modification–induced improvement in insulin resistance has contributed to a significant reduction in cSBP during OGTT in overweight/obese men.

Meal timing effects on insulin sensitivity and intrahepatic triglycerides during weight loss.

Several human and rodent studies suggest that in addition to the amount of energy consumed, timing of food intake contributes to body weight regulation. Consuming most energy in the morning has favorable effects on weight loss and weight maintenance. Whether this also affects glucose metabolism and liver fat independently from weight loss is unknown. We hypothesized that during weight loss, consuming most energy in the morning improves insulin sensitivity and reduces hepatic fat content more than consuming most energy in the evening. Twenty-three obese insulin resistant men (age 59.9±7.9 years, body mass index 34.4±3.8 kg m-2) followed a 4-week hypocaloric diet intervention with either 50% of daily energy consumed in the morning (BF group) or evening (D group). Insulin sensitivity, measured with a two-step hyperinsulinemic euglycemic clamp using a glucose tracer, intrahepatic triglycerides (IHTG), measured using magnetic resonance spectroscopy, and resting energy expenditure (REE) were assessed before and after the diet intervention. Meal macronutrient composition and weight loss (6.5±1.5% vs 6.2±1.9%, respectively, P=0.70) did not differ between the BF and D groups. Endogenous glucose production (P⩽0.001), hepatic and peripheral insulin sensitivity (P=0.002; P=0.001, respectively) as well as IHTG content (P⩽0.001) all significantly improved with weight loss, but were not different between the BF and D groups. In addition, both groups decreased REE and respiratory quotient equally. During weight loss, consuming most energy in the morning instead of the evening does not have additional beneficial effects on insulin sensitivity and IHTG content. These results do not support weight independent effects of meal timing on glucose metabolism and IHTG in hypocaloric conditions in obese men.

Influence of expression of UCP3, PLIN1 and PPARG2 on the oxidation of substrates after hypocaloric dietary intervention

In addition to environmental and psychosocial factors, it is known that genetic factors can also influence the regulation of energy metabolism, body composition and determination of excess weight. The objective of this study was to evaluate the influence of UCP3, PLIN1 and PPARG2 genes on the substrates oxidation in women with grade III obesity after hypocaloric dietary intervention. This is a longitudinal study with 21 women, divided into two groups: Intervention Group (G1): 11 obese women (Body Mass Index (BMI) ≥40kg/m2), and Control Group (G2): 10 eutrophic women (BMI between 18.5kg/m2 and 24.9kg/m2). Weight (kg), height (m), BMI (kg/m2), substrate oxidation (by Indirect Calorimetry) and abdominal subcutaneous adipose tissue were collected before and after the intervention. For the dietary intervention, the patients were hospitalized for 6 weeks receiving 1200kcal/day. There was a significant weight loss (8.4±4.3kg - 5.2±1.8%) and reduction of UCP3 expression after hypocaloric dietary intervention. There was a positive correlation between carbohydrate oxidation and UCP3 (r=0.609; p=0.04), PLIN1 (r=0.882; p=0.00) and PPARG2 (r=0.791; p=0.00) expression before dietary intervention and with UCP3 (r=0.682; p=0.02) and PLIN1 (r=0.745; p=0.00) genes after 6 weeks of intervention. There was a negative correlation between lipid oxidation and PLIN1 (r=-0.755; p=0.00) and PPARG2 (r=0.664; p=0.02) expression before dietary intervention and negative correlation with PLIN1 (r=0.730; p=0.02) expression after 6 weeks of hypocaloric diet. Hypocaloric diet reduces UCP3 expression in individuals with obesity and the UCP3, PLIN1 and PPARG2 expression correlate positively with carbohydrate oxidation and negatively with lipid oxidation.

Impact of hypocaloric dietary intervention on ovulation in obese women with PCOS.

Polycystic ovary syndrome (PCOS) is a common cause of ovulatory dysfunction impacting women of reproductive age. Obesity and insulin resistance are thought to potentiate disruptions in antral follicle development that result in chronic anovulation, and as such, have become important therapeutic targets of dietary interventions aimed at weight loss. Caloric restriction has been shown to promote sporadic ovulation in obese women with PCOS, but improvements have occurred across a wide range of patients and little has been garnered about the factors that distinguish responders from non-responders. Further, few studies have evaluated the likelihood for modest weight loss to restore normal ovulatory cyclicity in PCOS. Consensus regarding the impact of dietary intervention on ovulation has been limited by variability in the measures used to characterize and report ovulatory status across studies. In response, this review provides an assessment of the evidence surrounding the effectiveness of hypocaloric dietary intervention to normalize ovulatory function in PCOS. The impact of physiological versus methodological factors on the evaluation of ovulatory status is discussed and recommendations to strengthen future studies in this area are provided. Ultimately, further research is needed to understand the optimal dietary or lifestyle approaches that promote ovulation and sustained improvements in reproductive function in PCOS.

UCP2 expression is associated with weight loss after hypocaloric diet intervention.

Although energy restriction contributes to weight loss, it may also reduce energy expenditure, limiting the success of weight loss in the long term. Studies have described how genetics contributes to the development of obesity, and uncoupling proteins 1 and 2 (UCP1 and UCP2) and beta-3-adrenoceptor (ADRB3) have been implicated in the metabolic pathways that culminate in this condition. This study aimed to evaluate how the UCP1, UCP2 and ADRB3 genes influence weight loss in severely obese women submitted to hypocaloric dietary intervention. This longitudinal study included 21 women divided into two groups: Group 1 (Dietary intervention (G1)) consisted of 11 individuals with severe obesity (body mass index (BMI) ⩾40 kg/m2), selected for dietary intervention and Group 2 (Control (G2)) consisted of 10 normal-weight women (BMI between 18.5 and 24.9 kg/m2). Evaluation included weight (kg), height (m), waist circumference (cm), body composition, resting metabolic rate (RMR, kcal) and abdominal subcutaneous adipose tissue collection. The dietary intervention required that G1 patients remained hospitalized in the university hospital for 6 weeks receiving a hypocaloric diet (1200 kcal per day). The statistical analyses included t-test for paired samples, Spearman correlation and multivariate linear regressions, with the level of significance set at P<0.05. Weight (155.0±31.4-146.5±27.8 kg), BMI (58.5±10.5-55.3±9.2 kg/m2), fat-free mass (65.4±8.6-63.1±7.1 kg), fat mass (89.5±23.0-83.4±21.0 kg) and RMR (2511.6±386.1-2324.0±416.4 kcal per day) decreased significantly after dietary intervention. Multiple regression analyses showed that UCP2 expression contributed to weight loss after dietary intervention (P=0.05). UCP2 expression is associated with weight loss after hypocaloric diet intervention.

Low Glycemic Index and Load, Hypo Caloric Diet as an Effective Treatment for Obesity and Hyperlipidemia in Girls with Metabolic Syndrome

Objective: Considering the multiple complications of childhood obesity and metabolic syndrome (MS) at an early age, successful interventions are desperately needed. The aim of the study is to assess the effectiveness of a hypocaloric, low Glycemic Load (GL) and low Glycemic Index (GI) diet on the improvement of obesity and MS-related parameters. Methods: Fifty obese girls, aged 7-16 years, were randomly recruited from the Obesity Clinic of the First Department of Pediatrics, of the University of Athens. Half of the girls were randomly prescribed a 3-month hypocaloric dietary intervention emphasizing on portion control and low GL foods, versus no intervention in the control group. The dietary advice was according to the principles of the Mediterranean diet. Physical activity was kept constant. Anthropometric measurements, fasting blood lipids, glucose and prevalence of MS were assessed before and after the 3-months. Results: The girls in the intervention group exhibited a significant decrease in BMI, BMI z-score, waist circumference, total cholesterol and LDL compared to the control group (all p 0.05). Conclusions: This study demonstrates the efficacy of a hypocaloric-low GI/GL diet, incorporating adequate protein and healthy fat, in improving parameters of MS in obese children and adolescents. It suggests a positive role of the reduction in total carbohydrate intake and GI to the decrease in BMI z-score and DBP respectively. Further research is needed to confirm these results in the long-term.

Increased subcutaneous adipose tissue expression of genes involved in glycerolipid-fatty acid cycling in obese insulin-resistant versus -sensitive individuals.

A subpopulation of obese individuals remains insulin sensitive (ISO). They represent a unique human model to investigate factors underlying insulin resistance (IR) without the confounding effect of major differences in weight/adiposity. Altered fatty-acid (FA) metabolism in sc adipose tissue (SAT) contributes to obesity-associated IR. To test the hypothesis that ISO and body mass index-matched insulin-resistant obese (IRO) patients demonstrate differential SAT expression profiles of genes involved in glycerolipid-FA metabolism and that weight loss-induced improvement of IR ameliorates these changes. A cross-sectional and longitudinal study. Thirty-eight nondiabetic obese women were stratified into ISO (n = 25) or IRO (n = 13) groups based on hyperinsulinemic-euglycemic clamp results. Subjects were studied before and after a 6-month hypocaloric diet intervention. mRNA (quantitative RT-PCR) and protein (mass spectrometry and immunoblots) levels were measured in SAT biopsies. Despite having age, body mass index, and fat mass similar to ISO individuals, IRO patients had lower insulin sensitivity and glucose tolerance (P < .05). Baseline SAT mRNA and protein levels of genes involved in both the synthesis and lipolysis of glycerolipid-FAs were higher in IRO individuals (P < .05), even when groups were matched for visceral adipose tissue content. The dietary intervention resulted in approximately 6% weight loss in both the IRO and ISO groups (P < .05) but only ameliorated insulin sensitivity in IRO individuals (P < .05). Likewise, the intervention reduced the expression of most glycerolipid-FA metabolism genes (P < .05), with expression levels in IRO individuals being restored to ISO levels. Increased SAT expression of genes involved in both the synthesis and hydrolysis of glycerolipid-FAs is closely associated with IR in obese women. The results suggest that enhanced glycerolipid-FA cycling in SAT contributes to obesity-associated IR.

16-Weeks of Combined Aerobic and Resistance Training and Hypo-Caloric Diet on Measures of Arterial Stiffness in Overweight Pre-Menopausal Women

Objective: While diet and exercise reduce the risk of cardiovascular morbidity in overweight populations, the effects of combined aerobic and resistance training on arterial health has not been comprehensively examined. Methods: We investigated changes in both central and peripheral arterial stiffness using carotid artery distensibility and carotid to radial pulse wave velocity (PWVc-r), respectively, in twenty-five overweight, young women who participated in 16-weeks of 5-7 d/wk aerobic exercise, 2 d/wk resistance training, and hypo-caloric diet intervention. Pro-Collagen Type I C-Peptide (PIP) was used as a marker of type I collagen synthesis and C-telopeptide of type I collagen (CTX), a marker of type I collagen degradation. Results: Carotid artery distensibility was unaltered (Pre: 5.1×10-3 ± 3.9×10-4 vs. Post: 5.5×10-3 ± 3.5×10-4, p=0.26); however, PWVc-r increased following the intervention (Pre: 8.1 ± 0.3 m/s vs. Post: 8.9 ± 0.3 m/s, p<0.05). There were no changes in PIP (Pre: 1188 ± 91 ng/mL vs. Post: 1222 ± 94 ng/mL, p = 0.69), however, CTX increased with the intervention (0.65 ± 0.01 ng/mL vs. Post: 0.80 ± 0.02 ng/mL, p<0.001). There were no relationships between markers of collagen turnover and arterial stiffness measures. Conclusion: The intervention did not alter carotid artery distensibility or circulating markers of type I collagen synthesis but was associated with increased PWVc-r and CTX. Therefore, 16-weeks of diet and combined aerobic and resistance training may lead to increased peripheral artery stiffness, as measured by PWVc-r, however, cardiovascular risk assessed by carotid artery distensibility remained unchanged.