Analysis of weight loss outcomes using VLCD in black and white overweight and obese women with and without metabolic syndrome

Calorie restriction modulates mitochondrial dynamics and autophagy in leukocytes of patients with obesity

BACKGROUND

Although it is established that caloric restriction offers metabolic and clinical benefits, the molecular mechanisms underlying these effects remain unclear. Thus, this study aimed to investigate whether caloric restriction can modulate mitochondrial function and remodeling and stimulate autophagic flux in the PBMCs of patients with obesity.

METHODS

This was an interventional study of 38 obese subjects (BMI >35 kg/m2) who underwent 6 months of dietary therapy, including a 6-week very-low-calorie diet (VLCD) followed by an 18-week low-calorie diet (LCD). We determined clinical variables, mitochondrial function parameters (by fluorescence imaging of mitochondrial ROS and membrane potential), and protein expression of markers of mitochondrial dynamics (MNF1, MFN2, OPA, DRP1 and FIS1) and autophagy (LC3, Beclin, BCL2 and NBR1) by Western blot.

RESULTS

Caloric restriction induced an improvement in metabolic outcomes that was accompanied by an increase in AMPK expression, a decrease of mitochondrial ROS and mitochondrial membrane potential, which was associated with increased markers of mitochondrial dynamics (MFN2, DRP1 and FIS1) and activation of autophagy as evidenced by augmented LC3 II/I, Beclin1 and NBR1, and a decrease in BCL2.

CONCLUSION

These findings shed light on the specific molecular mechanisms by which caloric restriction facilitates metabolic improvements, highlighting the relevance of pathways involving energy homeostasis and cell recovery, including mitochondrial function and dynamics and autophagy.

Caloric restriction improves glycaemic control without reducing plasma branched-chain amino acids or keto-acids in obese men

Higher plasma leucine, isoleucine and valine (BCAA) concentrations are associated with diabetes, obesity and insulin resistance (IR). Here, we evaluated the effects of 6-weeks very-low calorie diet (VLCD) upon fasting BCAA in overweight (OW) non-diabetic men, to explore associations between circulating BCAA and IR, before and after a weight loss intervention. Fasting plasma BCAAs were quantified in an OW (n = 26; BMI 32.4 ± 3 kg/m²; mean age 44 ± 9 y) and a normal-weight (NW) group (n = 26; BMI 24 ± 3.1 kg/m²; mean age 32 ± 12.3 y). Ten of the OW group (BMI 32.2 ± 4 kg/m²; 46 ± 8 y) then underwent 6-weeks of VLCD (600-800 kcal/day). Fasting plasma BCAA (gas chromatography-mass spectrometry), insulin sensitivity (HOMA-IR) and body-composition (DXA) were assessed before and after VLCD. Total BCAA were higher in OW individuals (sum leucine/isoleucine/valine: 457 ± 85 µM) compared to NW control individuals (365 ± 78 µM, p < 0.001). Despite significant weight loss (baseline 103.9 ± 12.3 to 93 ± 9.6 kg and BMI 32.2 ± 4 to 28.9 ± 3.6 kg/m²), no changes were observed in BCAAs after 6-weeks of VLCD. Moreover, although VLCD resulted in a significant reduction in HOMA-IR (baseline 1.19 ± 0.62 to 0.51 ± 0.21 post-VLCD; p < 0.001), Pearson's r revealed no relationships between BCAA and HOMA-IR, either before (leucine R²: 2.49e-005, p = 0.98; isoleucine R²: 1.211-e006, p = 0.9; valine R²: 0.004, p = 0.85) or after VLCD (leucine R²: 0.003, p = 0.86; isoleucine R²: 0.006, p = 0.82; valine R²: 0.002, p = 0.65). Plasma BCAA are higher in OW compared to NW individuals. However, while 6-weeks VLCD reduced body weight and IR in OW individuals, this was not associated with reductions in BCAA. This suggests that studies demonstrating links between BCAA and insulin resistance in OW individuals, are complex and are not normalised by simply losing weight.

A Systematic Review of Literature on the Representation of Racial and Ethnic Minority Groups in Clinical Nutrition Interventions

The racial and ethnic disparities in diet-related chronic diseases are major concerns. This systematic review examines the extent to which diet-induced changes in health outcomes, such as cardiometabolic, inflammation, cancer, bone health, and kidney function outcomes, etc., have been reported and discussed by race or ethnicity in randomized trials with 2 or more diet arms that recruited both minority and non-Hispanic White groups. Databases (i.e., PubMed, Cochrane Library, and Web of Science) were searched up to August 2021. Thirty-four studies that discussed effects of defined dietary interventions on health outcomes by racial or ethnic minority group compared with non-Hispanic Whites were included in the systematic review (PROSPERO registration number: CRD42021229256). Acute trials and those with 1 diet arm that accounted for race or ethnicity in their analyses and studies that focused on a single racial or ethnic group were discussed separately. Most studies were conducted in Black compared with White adults testing effects of energy restriction, macronutrient modification, sodium reduction, or variations of the Dietary Approaches to Stop Hypertension (DASH) diet on cardiometabolic outcomes. There was limited focus on other minority groups. Evidence suggests greater blood pressure reduction for Black adults compared with Whites particularly with DASH (or similar) diets. Overall, there was limited consideration for group-specific eating patterns and diet acceptability. Overall risk of bias was low. With emerging precision nutrition initiatives that aim to optimize metabolic responses in population subgroups through tailored approaches, it is imperative to ensure adequate representation of racial and ethnic subgroups for addressing health disparities. Factors that help explain variability in responses such as socioecological context should be included and adequately powered. Given the racial and ethnic disparities in chronic diseases, studying the adoption, maintenance, and effectiveness of dietary interventions on health outcomes among different groups is critical for developing approaches that can mitigate diet-related health disparities.

Systemic Effects of Cryolipolysis in Central Obese Women: A Randomized Controlled Trial

BACKGROUND AND OBJECTIVES

To investigate the adding effect of Cryolipolysis to a low-calorie diet program on lipid profile, liver enzymes, body mass index, waist-to-hip ratio, and volume reduction of subcutaneous fat tissue in central obese women.

STUDY DESIGN/MATERIALS AND METHODS

Sixty central obese women were randomly divided into two equal groups. Women in the control group received prescribed low-calorie diet regimen only, while women in the study group received three Cryolipolysis sessions plus the same dietary regimen for 3 months. Assessment of women in each group for weight, height to obtain the body mass index, waist-to-hip ratio, and abdominal subcutaneous fat thickness as well as evaluation of lipid profile and liver enzymes was done just before starting the treatment procedures and immediately after ending the study duration.

RESULTS

There were statistically significant improvements of waist-to-hip ratio, body mass index, total cholesterol, triglycerides, low- and high-density lipoprotein, as well as liver enzymes in favor of the study group (P < 0.001).

CONCLUSION

Women who underwent Cryolipolysis and diet program had better improvement in components of lipid profile and liver enzymes than women who were maintained over diet program alone. Measures to decrease waist circumference, associated with abdominal subcutaneous fat reduction, enhanced the systemic effects of Cryolipolysis. Lasers Surg. Med. © 2020 Wiley Periodicals, Inc.

Effects of a 6-month caloric restriction induced-weight loss program in obese postmenopausal women with and without the metabolic syndrome: a MONET study

OBJECTIVE

To compare the effects of a caloric restriction (CR) on body composition, lipid profile, and glucose homeostasis in obese postmenopausal women with and without metabolic syndrome (MetS).

METHODS

Secondary analyses were performed on 73 inactive obese postmenopausal women (age 57.7 ± 4.8 years; body mass index 32.4 ± 4.6 kg/m) who participated in the 6-month CR arm of a study of the Montreal-Ottawa New Emerging Team. The harmonized MetS definition was used to categorize participants with MetS (n = 20, 27.39%) and without MetS (n = 53, 72.61%). Variables of interest were: body composition (dual-energy X-ray absorptiometry), body fat distribution (computed tomography scan), glucose homeostasis at fasting state and during a euglycemic/hyperinsulinemic clamp, fasting lipids, and resting blood pressure.

RESULTS

By design, the MetS group had a worse cardiometabolic profile, whereas both groups were comparable for age. Fifty-five participants out of 73 displayed no change in MetS status after the intervention. Twelve participants out of 20 (or 60.0%) in the MetS group had no more MetS after weight loss (P = NS), whereas 6 participants out of 53 (or 11.3%) in the other group developed the MetS after the intervention (P = NS). Overall, indices of body composition and body fat distribution improved significantly and similarly in both groups (P between 0.03 and 0.0001). Furthermore, with the exception of triglyceride levels and triglycerides/high-density lipoprotein cholesterol ratio, which decrease significantly more in the MetS group (P ≤ 0.05), no difference was observed between groups for the other variables of the cardiometabolic profile.

CONCLUSIONS

Despite no overall significant effects on MetS, heteregeneous results were obtained in response to weight loss in the present study, with some improving the MetS, whereas other displaying deteriorations. Further studies are needed to identify factors and phenotypes associated with positive and negative cardiometabolic responses to CR intervention.

Caloric Restriction and Its Effect on Blood Pressure, Heart Rate Variability and Arterial Stiffness and Dilatation: A Review of the Evidence

Essential hypertension, fast heart rate, low heart rate variability, sympathetic nervous system dominance over parasympathetic, arterial stiffness, endothelial dysfunction and poor flow-mediated arterial dilatation are all associated with cardiovascular mortality and morbidity. This review of randomised controlled trials and other studies demonstrates that caloric restriction (CR) is capable of significantly improving all these parameters, normalising blood pressure (BP) and allowing patients to discontinue antihypertensive medication, while never becoming hypotensive. CR appears to be effective regardless of age, gender, ethnicity, weight, body mass index (BMI) or a diagnosis of metabolic syndrome or type 2 diabetes, but the greatest benefit is usually observed in the sickest subjects and BP may continue to improve during the refeeding period. Exercise enhances the effects of CR only in hypertensive subjects. There is as yet no consensus on the mechanism of effect of CR and it may be multifactorial. Several studies have suggested that improvement in BP is related to improvement in insulin sensitivity, as well as increased nitric oxide production through improved endothelial function. In addition, CR is known to induce SIRT1, a nutrient sensor, which is linked to a number of beneficial effects in the body.

Relationship between body weight and the increment in serum brain-derived neurotrophic factor after oral glucose challenge in men with obesity and metabolic syndrome: A prospective study

Brain-derived neurotrophic factor (BDNF) plays a role in energy homeostasis. However, the postprandial BDNF change has not been well investigated. We hypothesized that the BDNF increment after oral glucose challenge is associated with body weight.To address this possibility, man adults with obesity in conjunction with metabolic syndrome were compared with normal weight controls at baseline in the initial cross-sectional protocol. The obese subjects then underwent a 12-week program for body-weight reduction in the prospective protocol. The area under the curve (AUC) of serum BDNF was recorded during a 75 g oral glucose tolerant test and the BDNF AUC index was defined as [(AUC of BDNF) - (fasting BDNF2 hours)]/(fasting BDNF2 hours).A total of 25 controls and 36 obese subjects completed the study assessments. In the cross-sectional protocol, the BDNF AUC index was significantly higher in the obese subjects than in the controls (9.0 ± 16.5% vs. - 8.0 ± 22.5%, P = 0.001). After weight reduction (from 97.0 ± 12.5 kg to 88.6 ± 12.9 kg, P < 0.001), the percentage change of body weight was significantly associated with the BDNF AUC index after the study (95% CI between 0.21 and 1.82, P = 0.015). Using 6% weight reduction as a cut-off value, a larger weight reduction was able to reliably predict a negative BDNF AUC index.In conclusion, a high BDNF AUC index was observed for obese men in this study, whereas the index value significantly decreased after body-weight reduction. These findings suggest that postprandial BDNF increment may be associated with obesity.

Relation between plasma antioxidant vitamin levels, adiposity and cardio-metabolic profile in adolescents: Effects of a multidisciplinary obesity programme

BACKGROUND & AIMS

In vivo and in vitro evidence suggests that antioxidant vitamins and carotenoids may be key factors in the treatment and prevention of obesity and obesity-associated disorders. Hence, the objective of the present study was to determine the relationship between plasma lipid-soluble antioxidant vitamin and carotenoid levels and adiposity and cardio-metabolic risk markers in overweight and obese adolescents participating in a multidisciplinary weight loss programme.

METHODS

A therapeutic programme was conducted with 103 adolescents aged 12-17 years old and diagnosed with overweight or obesity. Plasma concentrations of α-tocopherol, retinol, β-carotene and lycopene, anthropometric indicators of general and central adiposity, blood pressure and biochemical parameters were analysed at baseline and at 2 and 6 months of treatment.

RESULTS

Lipid-corrected retinol (P < 0.05), β-carotene (P = 0.001) and α-tocopherol (P < 0.001) plasma levels increased significantly, whereas lipid-corrected lycopene levels remained unaltered during the treatment. Anthropometric indicators of adiposity (P < 0.001), blood pressure (P < 0.01) and biochemical parameters (P < 0.05) decreased significantly, whereas fat free mass increased significantly (P < 0.001). These clinical and biochemical improvements were related to changes in plasma lipid-corrected antioxidant vitamin and carotenoid levels. The adolescents who experienced the greatest weight loss also showed the largest decrease in anthropometric indicators of adiposity and biochemical parameters and the highest increase in fat free mass. Weight loss in these adolescents was related to an increase in plasma levels of lipid-corrected α-tocopherol (P = 0.001), β-carotene (P = 0.034) and lycopene (P = 0.019).

CONCLUSIONS

Plasma lipid-soluble antioxidant vitamin and carotenoid levels are associated with reduced adiposity, greater weight loss and an improved cardio-metabolic profile in overweight and obese adolescents.

Cultural relevance of physical activity intervention research with underrepresented populations

This article describes cultural relevance in physical activity intervention research with underrepresented populations. Seventy-one extant studies which tested interventions to increase physical activity among underrepresented adults were included. Verbatim descriptions of efforts to enhance cultural relevance of study designs and interventions were extracted and then content analyzed. We found strategies to enhance cultural relevance of interventions as soliciting input from population members, linking intervention content with values, addressing language and literacy challenges, incorporating population media figures, using culturally relevant forms of physical activity, and addressing specific population linked barriers to activity. Methodological approaches included specialized recruitment and study locations, culturally relevant measures, underrepresented personnel, and cost-awareness study procedures to prevent fiscal barriers to participation. Most reported activities were surface matching. Existing research neither compared the effectiveness of cultural relevance approaches to standardized interventions nor addressed economic, education, geographic, or cultural heterogeneity among groups.

Impact of weight loss and maintenance with ad libitum diets varying in protein and glycemic index content on metabolic syndrome

OBJECTIVES

We investigated the effects of weight loss and maintenance with diets that varied with regard to protein content and glycemic index (GI) on metabolic syndrome (MetSyn) status.

METHODS

Secondary analyses were performed within the Diet, Obesity and Genes (DiOGenes) study (2006-2008), a randomized controlled dietary intervention. Nine hundred and thirty-eight overweight and obese adults from eight European countries entered an 8-wk low-calorie-diet period. Seven hundred and seventy-three adults who lost at least 8% of their body weights were randomized to one of five ad libitum diets for 6 mo: 1) low-protein (LP)/low-GI (LGI); 2) LP/high-GI (HGI); 3) high-protein (HP)/LGI; 4) HP/HGI; and 5) control diet. MetSyn prevalence and a standardized MetSyn score were assessed at baseline, after the low-calorie diet, and after the intervention.

RESULTS

Weight loss among participants while on the low-calorie diet significantly reduced MetSyn prevalence (33.9% versus 15.9%; P < 0.001) and MetSyn score (-1.48 versus -4.45; P < 0.001). During weight maintenance, significant changes in MetSyn score were observed between the groups, with the highest increase detected in the LP/HGI group (P = 0.039, partial η(2) = 0.023). Protein, GI, and their interaction did not have isolated effects on study outcomes.

CONCLUSIONS

Neither protein nor GI affected MetSyn status in this sample of European overweight and obese adults. However, a diet with a combination of an increased protein-to-carbohydrate ratio with low-GI foods had beneficial effects on MetSyn factors.

Physical activity interventions with healthy minority adults: meta-analysis of behavior and health outcomes

This meta-analysis is a systematic compilation of research focusing on various exercise interventions and their impact on the health and behavior outcomes of healthy African American, Hispanic, Native American, and Native Hawaiian adults. Comprehensive searching located published and unpublished studies. Random-effects analyses synthesized data to calculate effect sizes (ES) as a standardized mean difference (d) and variability measures. Data were synthesized across 21,151 subjects in 100 eligible samples. Supervised exercise significantly improved fitness (ES=.571-.584). Interventions designed to motivate minority adults to increase physical activity changed subsequent physical activity behavior (ES=.172-.312) and anthropometric outcomes (ES=.070-.124). Some ES should be interpreted in the context of limited statistical power and heterogeneity. Attempts to match intervention content and delivery with minority populations were inconsistently reported. Healthy minority adults experienced health improvements following supervised exercise. Interventions designed to motivate subjects to increase physical activity have limited magnitude heterogeneous effects.

Dietary interventions for weight loss and cardiovascular risk reduction in people of African ancestry (blacks): a systematic review

Objective

To systematically review weight and cardiovascular risk reduction in blacks by diet and lifestyle changes.

Design

Randomised and non-randomised controlled trials of diet with/without lifestyle changes with duration of intervention ≥3 months, and published between January 1990 and December 2009, were searched in electronic databases including MEDLINE, EMBASE, CINAHL and CCTR (Cochrane Controlled Trials Register). Studies were included if they reported weight/BMI changes with changes in at least one of the following: systolic and diastolic blood pressure, fasting plasma lipids and glucose, and glycated haemoglobin.

Setting

Clinical, community and church-based interventions.

Subjects

Study participants were of African ancestry (blacks).

Results

Eighteen studies met the inclusion criteria. Average mean difference in weight loss was −2·66 kg, with improvements in all outcomes except total cholesterol. No significant difference was observed in outcome measures between all studies and studies that recruited only healthy participants or patients with type 2 diabetes.

Conclusions

Diet and lifestyle changes result in weight loss with improvements in cardiovascular risk factors in blacks. However, more culturally tailored programmes have been suggested to motivate and encourage blacks to participate in intervention trials.

Pharmacotherapy for overweight/obesity in ethnic minorities and White Caucasians: a systematic review and meta-analysis

Ethnic minorities in the West exhibit a higher prevalence of obesity and also under-achieve in weight management compared to White Caucasians. A systematic review of randomized controlled trials (RCTs) in adults (mean age ≥18 years, duration ≥6 months and published in the English language) was undertaken to evaluate the effectiveness of antiobesity drugs in ethnic minorities and White Caucasians. Data sources between 1990 and 2010 were searched including MEDLINE, EMBASE, Cochrane Controlled Trials Register, CINAHL and references cited in the included studies of other reviews. Eighteen RCTs that met the inclusion criteria were included in this review (6 sibutramine and 12 orlistat). A random effects model was used for meta-analysis. An indirect comparison of weight loss in sibutramine-treated patients in ethnic minorities was significantly lower than in White Caucasians: -2.7 kg (95% CI: -3.1 to -2.3) versus -4.4 kg (95% CI: -5.0 to -3.8), respectively. For orlistat, weight loss was similar in the two groups: -2.3 kg (95% CI: -2.6 to -2.0) in ethnic minorities and -2.8 kg (95% CI: -5.1 to -0.5) in White Caucasian participants. Overall, there were few studies of weight loss pharmacotherapy for comparison of this review and it was not possible to analyse data based on ethnic groupings. More ethnically tailored studies are needed to assess the most effective weight loss strategies in these most metabolically vulnerable groups.

The Effects of Very-Low-Calorie Diets on HDL: A Review

This paper investigates the effects of very-low-calorie diets (VLCDs) used in the treatment of obesity on high-density lipoprotein (HDL) levels. Although the studies varied widely in their intervention format, duration, and baseline HDL levels, it would appear that HDL levels usually decrease during active weight loss using a VLCD, but these either return to pre-VLCD levels or improve overall during the weight-maintenance phase. More research needs to be done to determine optimal weight-maintenance programmes and the effects of VLCDs in the short term as well as on HDL levels in groups at increased risk of coronary heart disease.

Efficacy and safety of very-low-calorie diet in Taiwanese: a multicenter randomized, controlled trial

OBJECTIVE

Very-low-calorie diets (VLCDs) are an effective method for weight reduction in Caucasians. This study investigated the efficacy and safety of two different VLCDs (450 or 800kcal/d) in obese Taiwanese.

METHODS

132 participants with BMI > or =30kg/m(2) were randomized to two VLCD groups for body weight reduction for 12 weeks. Each group had 66 participants. Anthropometric and metabolic parameters were measured.

RESULTS

The intention-to-treat analysis revealed that the percentage change in body weight over the 12-week treatment period was -9.14% in the VLCD-450 group and -8.98% in the VLCD-800 group. A total of 27 (40.9%) participants in the VLCD-450 group and 29 (43.9%) participants in the VLCD-800 group achieved 10% or more weight loss at the end of treatment. The body weight, waist circumference, hip circumference, fat mass, blood pressure, triglycerides, and blood glucose were statistically improved from baseline but not between the two groups. The improvement rate of nonalcoholic fatty liver disease (NAFLD) was 41.5% in the VLCD-450 group and 50.0% in the VLCD-800 group. The incidence of adverse events did not differ significantly between the groups and no serious adverse events were reported in either group.

CONCLUSION

Both the VLCD-450 and 800kcal/d can effectively and safely reduce body weight and improve NAFLD in 12 weeks in obese Taiwanese participants. However, there is no additional benefit in prescribing the more restrictive diet intervention in Taiwanese.

Preoperative weight loss is not a predictor of postoperative weight loss after laparoscopic Roux-en-Y gastric bypass

BACKGROUND

Identification of preoperative predictors of weight loss after laparoscopic Roux-en-Y gastric bypass (LRYGB) can lead to improved clinical outcomes. The purpose of this study was to determine whether preoperative weight loss was associated with improved percentage of excess weight loss (%EWL) 1 year after LRYGB.

METHODS

A retrospective analysis was performed on the data from 295 patients who had undergone LRYGB at our institution from July 2004 to November 2005. Routine preoperative weight loss goals were implemented to facilitate the laparoscopic approach and ensure compliance with an appropriate nutritional and exercise program. Patients with an initial consultation BMI of <50, 50-59, and > or =60 kg/m(2) were given weight loss goals of 5 lb and 5% and 10% of body weight, respectively.

RESULTS

The mean age was 45 +/- 10 years, and 89% were women and 70% were white. The mean BMI at the initial consultation was 51 +/- 7 kg/m(2). A significant inverse correlation was found between the preoperative BMI and %EWL at 1 year postoperative (P <.001). When controlling for BMI, no correlation was found between the %EWL and percentage of preoperative weight loss or attainment of the weight loss goals. The weight loss goals were met or surpassed by 79% of patients, and the mean %EWL at 1 year was 66%. Whites had greater %EWL at 1 year postoperatively compared with African Americans (67% versus 61%; P = .002). When controlling for age, gender, race, and consultation BMI, the preoperative weight loss did not predict for the %EWL at 1 year.

CONCLUSION

The results of this study have shown that preoperative weight loss does not predict postoperative weight loss 1 year after LRYGB. A lower BMI, younger age, and white race predicted better %EWL.