Towards a qualitative theory of the interruption of eating behavior change

The poor maintenance of eating behavior change is one of the main obstacles to minimizing weight regain after weight loss during diets for non-surgical care of obese or overweight patients. We start with a known informal explanation of interruption in eating behavior change during severe restriction and formalize it as a causal network involving psychological variables, which we extend with energetic variables governed by principles of thermodynamics. The three core phenomena of dietary behavior change, i.e., non-initiation, initiation followed by discontinuation and initiation followed by non-discontinuation, are expressed in terms of the value of the key variable representing mood or psychological energy, the fluctuation of which is the result of three causal relationships. Based on our experimental knowledge of the time evolution profile of the three causal input variables, we then proceed to a qualitative analysis of the resulting theory, i.e., we consider an over-approximation of it which, after discretization, can be expressed in the form of a finite integer-based model. Using Answer Set Programming, we show that our formal model faithfully reproduces the three phenomena and, under a certain assumption, is minimal. We generalize this result by providing all the minimal models reproducing these phenomena when the possible causal relationships exerted on mood are extended to all the other variables (not just those assumed in the informal explanation), with arbitrary causality signs. Finally, by a direct analytical resolution of an under-approximation of our theory, obtained by assuming linear causalities, as a system of linear ODEs, we find exactly the same minimal models, proving that they are also equal to the actual minimal models of our theory since these are framed below and above by the models of the under-approximation and the over-approximation. We determine which parameters need to be person-specific and which can be considered invariant, i.e., we explain inter-individual variability. Our approach could pave the way for universally accepted theories in the field of behavior change and, more broadly, in other areas of psychology.

Efficacy and Safety of Intragastric Balloon Therapy Compared to a Multidisciplinary Weight Loss Program (OPTIFAST) in a Real-World Population: A Propensity Score Matching Analysis

INTRODUCTION

Obesity is a major global health problem associated with comorbidities such as diabetes, cardiovascular disease, and cancer. Bariatric surgery is recognized to be the most effective weight loss intervention, but it is highly invasive and costly and can have serious side effects. Intragastric balloon (IGB) placement by endoscopy and hypocaloric diets are among a number of techniques that have been used in patients unsuitable for, or unwilling to undergo, obesity surgery. In this study, we compared the efficacy, safety, and cost-effectiveness of the hypocaloric OPTIFAST program (OPT) with endoscopic IGB placement for weight loss.

METHODS

In this retrospective observational cohort propensity score-weighted comparison (performed May 2014 to December 2020), participants with a BMI of 30-55 kg/m2, aged 18-70 years, were randomized to OPT or IGB for 26 weeks, followed by a weight maintenance phase. Patients were matched according to age, gender, and BMI. The study outcomes were percentage excess body weight lost, total body weight lost (TBWL), and percentage TBWL (%TBWL).

RESULTS

A total of 148 participants (75% of those randomized; 74 OPT, 74 IGB) made up the ITT population. Mean age was 44.1 ± 10.4 years, and the patients were predominantly female (77%). Baseline BMI was 44.1 ± 10.4 kg/m2. At 26 weeks, %TBWL in the OPT group was 19.6 ± 6.8% versus 11.9 ± 6.7% for IGB (p < 0.001). At 52 weeks, %TBWL for OPT was 18.2 ± 9.0% versus 12.0 ± 6.6% for IGB (p < 0.001). The OPT cohort also experienced significantly fewer adverse events compared with the IGB group.

CONCLUSION

IGB placement and OPT induce clinically meaningful weight loss. However, OPT appears to induce clinically superior weight loss and has economic advantages through lower rates of complications and adverse events.

A Prospective Non-Randomized Open-Label Comparative Study of The Effects of Matcha Tea on Overweight and Obese Individuals: A Pilot Observational Study

Matcha tea has been used as an adjunct in weight loss programs. The weight loss effects of matcha tea were evaluated in a prospective non-randomized open-label comparative study of overweight and obese individuals who followed a specified low-calorie diet (LCD) plan. A total of 40 participants were enrolled and assigned to either matcha tea or control groups. The matcha tea group followed a LCD plan and received matcha tea once daily, whereas the control group followed only the LCD diet plan. The study lasted 12 weeks. The main outcome measures included anthropometric measurements, fasting blood glucose, hemoglobin A1c (HbA1c), lipid profile, obesity-related hormone peptides, pro-inflammatory and anti-inflammatory cytokines, and oxidative stress biomarkers. Thirty-four participants had completed the study. The matcha tea and control groups showed significant reductions in body weight, body mass index, waist circumference, water content, minerals, and fat mass at week 12. The post-treatment body composition and anthropometric measurements were not significantly different between the two groups. The matcha tea group showed a potential increase in HDL-C, a potential decrease in blood glucose, and a potential increase in HbA1c. Furthermore, the study indicated a potential decrease in insulin and leptin levels, a potential increase in the activity of superoxide dismutase, and a potential decreased activity of glutathione peroxidase. IL-10 was increased by matcha tea consumption. The data suggest that matcha tea may have some potential effect on weight loss, along with anti-inflammatory properties. The findings of this study will be used to design a multicenter randomized clinical trial to examine the potential weight loss benefits of matcha tea.

The risk variant of CDKAL1 (rs7756992) impairs fasting glucose levels and insulin resistance improvements after a partial meal-replacement hypocaloric diet

BACKGROUND

The CDKAL1 (CDK5 Regulatory Subunit Associated Protein 1 Like 1) gene encodes cyclin-dependent kinase 5 (CDK5) regulatory subunit-associated proten1 like 1. This protein has been shown to contribute to the glucose-dependent regulation of insulin secretion in pancreatic islets.

AIMS

The aim of our study was to analyze the effects of the rs7756992 genetic variant of CDKAL1 gene on fasting glucose and insulin resistance after weight loss secondary to partial meal replacement hypocaloric diet (pMRHD).

METHODS

This was a non-randomized, single-treatment study with a formula-diet in 44 obese subjects. The patients received nutritional education and a modified diet with two intakes of a normocaloric hyperproteic formula for 3-months. Anthropometric parameter and biochemical profile were measured at basal time and after 3 months. The variant of CDKAL1 gene rs7756992 was assessed.

RESULTS

The following genetic distribution was observed; [27AA (61.3%), 12 AG (27.3%) and 5 GG (11.4%)]. After the pMRHD, body weight, the body mass index (BMI), fat mass, waist circumference and blood pressure decreased in both genotypes. Non-G allele carriers showed a significant improvement in fasting glucose levels (AA vs. AG + GG) (-6.1 ± 1.4 md/dl vs. -1.2 ± 0.7 mg/dl; p = 0.01), fasting insulin levels (-3.6 ± 0.2 mU/l vs. -1.3 ± 0.6 mU/l; p = 0.02) and HOMA-IR (-1.2 ± 0.2 units vs. -0.3 ± 0.2 units; p = 0.01). Fasting plasma glucose levels were higher in G allele carriers than non G allele carriers.

CONCLUSIONS

Our data suggest that the genetic variant (rs7756992) of CDKAL1 gene is associated with glycaemic status after a pMRHD, with greater improvements in fasting glucose, insulin and HOMA-IR in subjects without the G allele.

The risk variant of CDKAL1 (rs7756992) impairs fasting glucose levels and insulin resistance improvements after a partial meal-replacement hypocaloric diet

BACKGROUND

The CDKAL1 (CDK5 Regulatory Subunit Associated Protein 1 Like 1) gene encodes cyclin-dependent kinase 5 (CDK5) regulatory subunit-associated proten1 like 1. This protein has been shown to contribute to the glucose-dependent regulation of insulin secretion in pancreatic islets.

AIMS

The aim of our study was to analyze the effects of the rs7756992 genetic variant of CDKAL1 gene on fasting glucose and insulin resistance after weight loss secondary to partial meal replacement hypocaloric diet (pMRHD).

METHODS

This was a non-randomized, single-treatment study with a formula-diet in 44 obese subjects. The patients received nutritional education and a modified diet with two intakes of a normocaloric hyperproteic formula for 3-months. Anthropometric parameter and biochemical profile were measured at basal time and after 3 months. The variant of CDKAL1 gene rs7756992 was assessed.

RESULTS

The following genetic distribution was observed; [27AA (61.3%), 12 AG (27.3%) and 5 GG (11.4%)]. After the pMRHD, body weight, the body mass index (BMI), fat mass, waist circumference and blood pressure decreased in both genotypes. Non-G allele carriers showed a significant improvement in fasting glucose levels (AA vs. AG + GG) (-6.1 ± 1.4 md/dL vs. -1.2 ± 0.7 mg/dl; p = 0.01), fasting insulin levels (-3.6 ± 0.2 mU/L vs. -1.3 ± 0.6 mU/L; p = 0.02) and HOMA-IR (-1.2 ± 0.2 units vs. -0.3 ± 0.2 units; p = 0.01). Fasting plasma glucose levels were higher in G allele carriers than non G allele carriers.

CONCLUSIONS

Our data suggest that the genetic variant (rs7756992) of CDKAL1 gene is associated with glycaemic status after a pMRHD, with greater improvements in fasting glucose, insulin and HOMA-IR in subjects without the G allele.

Does Dietary Intake Impact Omentin Gene Expression and Plasma Concentration? A Systematic Review

BACKGROUND

Omentin is an adipokine with anti-inflammatory and insulin-sensitizing effects that can play a protective role against cardiovascular disease and diabetes. The aim was to systematically review and summarize the existing evidence on the association between overall dietary intake and omentin gene expression and circulation.

SUMMARY

A literature search was conducted in PubMed, Scopus, and Web of Science up to September 2019. Of the 1,940 retrieved articles, 20 relevant studies were included, 6 of which were observational, 11 were clinical trials in humans, and 3 were animal studies. Four randomized controlled trials (RCTs) had a high risk of bias (RoB), 1 had "some concerns", and 2 had a low RoB. Among the nonrandomized studies with comparators, 4 had a serious RoB and 2 had a moderate RoB. In the experimental animal studies with a moderate RoB, conflicting results for omentin serum concentration were found for high-fat and low-fat diets. A high-fat diet (HFD) was shown to reduce omentin gene expression in one animal study. In the observational studies, omentin serum concentration was reduced by Ramadan fasting and saturated fatty acid (SFA) intake, and an increase in omentin gene expression was observed with monounsaturated fatty acid (MUFA) intake. There was no association of dietary inflammatory index (DII), macronutrient intake, or total calorie intake with omentin plasma concentrations. In the human interventional studies, omentin plasma concentration increased with a long-term low-calorie, low-fat diet (LFD), and no change was seen with a HFD or a short-term low-calorie diet (LCD). Key Messages: It seems that a long-term diet with a lower fat content and a balanced distribution of fatty acids, i.e., a higher MUFA and lower SFA intake, may effectively increase omentin plasma concentration, possibly via improved insulin resistance and reduced inflammation, but more research is needed to confirm or refute this.

Whey protein supplementation reducing fasting levels of anandamide and 2-AG without weight loss in pre-menopausal women with obesity on a weight-loss diet

Background

Despite the importance of dairy proteins in modifying of metabolic abnormalities, no attention has been given to their effects on endocannabinoids.

Methods

A total number of 60 obese women were recruited in a 2-month randomized clinical trial. Following random allocation, they were assigned to one of the two groups: control (n = 30) and intervention (n = 30). Then, all the subjects followed a hypocaloric diet of 800 kcal below estimated energy needs. The intervention group received isocaloric weight-loss diet and whey protein powders (30 g/day). Baseline and 2-month fasting anthropometric, blood glucose, serum insulin, insulin resistance, lipid profile, AEA, and 2-AG were measured.

Results

The study groups were homogenous in terms of baseline characteristics (p > 0.05) except for MUFA intake (p = 0.021). There were no significant differences in energy and macronutrient intakes in the intervention group compared to the control group at the end of the study (p > 0.05). The results of the ANCOVA did not show significant reductions in body weight and BMI of the intervention group compared to the control group (p > 0.05); however, WC, body fat, FBS, AEA, 2-AG, total cholesterol, and triglyceride decreased and HDL-c significantly increased in the intervention group compared to the control group (p < 0.05).

Conclusions

In this study, the effects of simultaneous weight-loss diet and whey protein supplementation on the reduction of endocannabinoids were determined.

Trial registration

Iranian Registry of Clinical Trials IRCT2017021410181N8. Registered on March 2017.

Diets with lower carbohydrate concentrations improve insulin sensitivity in women with polycystic ovary syndrome: A meta-analysis

OBJECTIVE

Women with polycystic ovary syndrome (PCOS) are associated with increased levels of insulin resistance (IR). Other than treatment with insulin-sensitizing drugs, specialized diets have also been implemented to reduce the patient's IR. However, the capacity of certain diets, concerning with the severity of the patient's IR, to improve insulin sensitivity has not fully been explored. Therefore, we conducted a meta-analysis to determine in PCOS subjects from low to severe IR, if hypocaloric diets improve insulin sensitivity.

STUDY DESIGN

PubMed, SCOPUS, EBSCO, and LILACS databases and retrieved studies' bibliographies were searched for prospective studies that investigated the association between diets and IR in PCOS women until October 2018. Diet was defined as a modification of the patients' nutrition intake according to caloric restriction, change in protein intake, or by using a specialized diet. IR measures (HOMA1-IR), pre- and post-intervention were extracted. Using Comprehensive Meta-Analysis software, depending on the level heterogeneity, determined by the ψ²-based Q-test and the I²-test, fixed-effects or random-effects models were used to calculate the pooled standard paired differences (SPD) and 95 %CI.

RESULTS

20 publications (25 studies) fulfilled the inclusion criteria. Due to the heterogeneity of the diets, the random-effects model was used. In 48 % of the studies, the diets led to a decrease of IR, where 44 % had no effect. In 2 studies, the diets increased IR. Overall, the diets decreased IR (SPD=-0.58; 95 %CI: -0.81 to -0.36). Subjects with severe IR (HOMA1-IR>4.2) had a marked improvement (SPD=-1.22; 95 %CI: -1.61 to -0.84). Moreover, diets low in carbohydrate (<50 %) was also determined to improve IR (SPD=-0.86; 95 %CI: -1.23 to -0.50).

CONCLUSIONS

Here, we demonstrate that diets are more likely to improve IR in PCOS women with severe IR. Therefore, it is crucial to determine a subject's IR status before considering any intervention containing a diet.

Changes in body composition with a hypocaloric diet combined with sedentary, moderate and high-intense physical activity: a randomized controlled trial

BACKGROUND

There is evidence showing the effectiveness of a hypocaloric diet and the increase in physical activity on weight loss. However, the combined role of these factors, not only on weight loss but also body composition, remains unclear. The purpose of this study was to investigate the effect of a hypocaloric diet on the body composition of obese adult women throughout different degrees of physical activity during a weight loss program.

METHODS

One hundred and seventeen healthy female volunteers were randomly assigned to one of the experimental groups: a control group with a low-level prescription of physical activity (1-4 METs), moderate physical activity group that performed 10.000 steps walking (5-8 METs) and intense physical activity group that trained exercises by at least 70% of VO2max three times a week (> 8 METs). All subjects followed a hypocaloric diet designed with a reduction of 500 kcal/day. Nutritional counseling was provided throughout the study period to help ensure dietary adherence.

RESULTS

We found no differences in body weight compared to moderate and intense physical activity (ßstand. = - 0.138 vs. ßstand. = - 0.139). Body fat was lower in women following an intense activity (ßstand. = - 0.436) than those with moderate exercise (ßstand. = - 0.231). The high-intense activity also increased muscle mass at the end of the intervention, standing out above the moderate activity (ßstand. = 0.182 vs. ßstand. = 0.008).

CONCLUSIONS

These findings indicate that a hypocaloric diet, without prescription of physical activity, is adequate to lose weight in the short term (12 weeks), but physical activity is vital to modify the body composition in women with obesity. Body fat was lower when women practiced a moderate exercise compared to hypocaloric diet only, but an intense physical activity was the most effective protocol to obtain a reduction of body fat and maintain muscle mass.

TRIAL REGISTRATION

The study protocol complied with the Declaration of Helsinki for medical studies, it was approved by the bioethical committee of Córdoba University, in the Department of Health at the Regional Government of Andalusia (Act n°284, ref.4156) and retrospectively registered in clinicaltrials.gov (NCT03833791). Registered 2 January 2019.

Adiponectin Gene Variant rs266729 Interacts with Different Macronutrient Distribution of Two Different Hypocaloric Diets

BACKGROUND

The role of ADIPOQ gene variants in weight loss after different dietary fat amounts remains unclear.

OBJECTIVE

Our aim was to analyze the effects of ADIPOQ gene polymorphism rs266729 on metabolic changes after two different amounts of dietary fat in two hypocaloric diets.

DESIGN

A population of 283 obese patients was recruited in a randomized clinical trial with two diets: Diet HF (high-fat diet: 38% carbohydrates, 24% proteins, and 38% fats) versus Diet LF (low-fat diet: 53% carbohydrates, 20% proteins, and 27% fats). Before and after 3 months, an anthropometric evaluation, an assessment of nutritional intake, and a biochemical analysis were carried out. The variant of the ADIPOQgene was assessed by real-time PCR.

RESULTS

Weight loss was similar with both diets in both genotypes (CC vs. CG+GG). After dietary intervention with Diet HF, only subjects with CC genotype showed a significant improvement in insulin levels (-3.3 ± 0.6 vs. -1.8 ± 0.9 mU/L; p = 0.03) and the homeostasis model assessment for insulin resistance (HOMA-IR) (-1.3 ± 0.1 vs. -0.8 ± 0.2 units; p = 0.02). After Diet LF, subjects with CC genotype showed a significant improvement in total cholesterol levels (CC vs. CG+GG) (-15.3 ± 1.4 vs. -6.4 ± 1.3 mg/dL; p = 0.01), LDL cholesterol (-14.6 ± 1.8 vs. -6.4 ± 1.3 mg/dL; p = 0.01), insulin levels (-4.6 ± 1.0 vs. -1.6 ± 0.5 mU/L; p = 0.01), and HOMA-IR (-1.6 ± 0.1 vs. -1.0 ± 0.2 units; p = 0.02). Only subjects with CC genotype showed a significant increase of adiponectin levels after both diets (CC vs. CG+GG): Diet HF (10.6 ± 2.0 vs. 1.8 ± 1.0 ng/dL; p = 0.01) and Diet LF (16.1 ± 2.8 vs. 1.3 ± 1.0 ng/dL: p = 0.03).

CONCLUSION

CC genotype of ADIPOQgene variantrs266729 was associated with a better metabolic response after both diets. Additionally, Diet LF produced a significant improvement in lipid profile in noncarriers of allele G.

Different effects of high-protein/low-carbohydrate versus standard hypocaloric diet on insulin resistance and lipid profile: Role of rs16147 variant of neuropeptide Y

BACKGROUND AND AIMS

Few studies have assessed the effect of the NPY gene rs16147 variant on metabolic response following a dietary intervention. We evaluated the effect of rs16147 on body weight and biochemical changes after a high-protein/low-carbohydrate hypocaloric diet compared with a standard severe hypocaloric diet over 9 months.

MATERIALS AND METHODS

A population of 270 obese individuals was enrolled. At baseline, participants were randomly allocated to one of two hypocaloric diets, high protein (Diet HP) or standard (Diet S), for a period of 9 months.

RESULTS

After both diets, all genotypes showed decreased body mass index, weight, fat mass, waist circumference, and leptin levels. Participants with the minor allele (A) assigned to the HP diet showed decreases in total cholesterol (-6.5 ± 4.8 vs 10.1 ± 4.1 mg/dL; p < 0.05), LDL cholesterol (-5.9 ± 3.8 vs 9.6 ± 2.4 mg/dL; p < 0.05), triglycerides (-1.0 ± 4.8 vs 16.2 ± 4.1 mg/dL; p < 0.05), insulin (-0.5 ± 2.8 vs 1.7 ± 2.1 UI/L; p < 0.05), HOMA-IR (-0.2 ± 2.1 vs 0.5 ± 2.0 units; p < 0.05), and CRP (-0.3 ± 0.4 vs 1.3 ± 0.2 mg/dL; p < 0.05). Participants with the minor allele assigned to diet S also showed decreases in total cholesterol (-6.1 ± 4.1 vs 14.4 ± 3.1 mg/dL; p < 0.05), LDL-cholesterol (-3.1 ± 2.8 vs 15.0 ± 3.1 mg/dL; p < 0.05), triglycerides (-6.9 ± 4.1 vs 13.2 ± 4.0 mg/dL; p < 0.05), insulin (-0.3 ± 2.1 vs. -1.2 ± 0.2 UI/L: p < 0.05), HOMA-IR (-0.3 ± 2.1 vs. -1.6 ± 1.1 units: p < 0.05), and CRP (-0.4 ± 0.1 vs 1.1 ± 0.2 mg/dL; p < 0.05).

CONCLUSION

In obese Caucasians, the presence of the A allele of the rs16147 genetic variant produces a better metabolic response that is secondary to weight loss with two different hypocaloric diets.

Increased fiber intake predicts the decrease in 2nd phase glucose-induced hyperinsulinemia following a hypocaloric diet in obese subjects

BACKGROUND AND AIMS

Higher fiber intake is associated with increased insulin sensitivity (IS) and reduced glucose-induced insulin secretion (GIIS) during isocaloric-diets; however, its role in hypocaloric-diets is unclear. We examined whether increased fiber intake predicts the amelioration in IS and GIIS following a hypocaloric-diet.

METHODS AND RESULTS

This is a post-hoc analysis of 55 adult subjects (BMI > 27 kg/m²) who completed a 6-month hypocaloric-diet (-500 kcal/day). Dietary intake was assessed using 3-day food records at baseline and post-intervention. We evaluated glucose-induced insulin and C-peptide secretions as AUC of plasma insulin and C-peptide during intravenous-glucose-tolerance tests (IVGTT) and IS via hyperinsulinemic-euglycemic clamps. Data analysis employed regression models and 2-way RM ANOVAs. Post-intervention % change in fiber intake was associated positively with IS_clamp (r = 0.30) and negatively with % change in total (r = -0.37) and 2nd phase GIIS_IVGTT (r = -0.44) but not C-peptide secretion. It remained associated with lower 2nd phase GIIS_IVGTT after adjustment for sex and % changes in BMI and energy-intake, independently of other macronutrients. Subjects who increased fiber intake (to 28.7 ± 9.0 g/day) had a greater decrease in 2nd phase GIIS_IVGTT, not C-peptide secretion, independently of sex or changes in adiposity or energy-intake compared to subjects who decreased intake (to 20.0 ± 6.8 g/day).

CONCLUSION

Higher fiber intake is an independent predictor of reduced 2nd phase glucose-induced hyperinsulinemia after a hypocaloric-diet. It was not associated with plasma C-peptide, suggesting a role in faster insulin clearance rather reduced insulin secretion. Promoting high-fiber intake may increase the effectiveness of hypocaloric-diets in preventing type 2 diabetes.

REGISTRATION

ISRCTN14476404, BioMedCentral.com.

CLINICAL TRIAL REGISTRATION

This trial was registered at BioMed Central as ISRCTN14476404, on July 28th, 2017.

Effect of weight loss on bone metabolism in postmenopausal obese women with osteoarthritis

BACKGROUND

The choice of hypocaloric diets in obesity can affect bone health.

AIMS

The aim of this study is to assess the effect of a hypocaloric diet in postmenopausal obese women and to determine the influence of weight reduction on bone metabolism.

METHODS

This was a non-randomised, single-treatment study in 96 postmenopausal women with a body mass index (BMI) greater than 35kg/m² and osteoarthritis. The patients received a formula diet with two intake levels of a normocaloric hyperproteic formula (1035kcal (25% protein)). Anthropometry and biochemistry with CrossLaps, osteocalcin, parathyroid hormone (PTH) and 25-OH vitamin D were measured. Consumption of protein, calcium and vitamin D were determined at the beginning of and 3 and 6 months into the study. The response to treatment was compared (high-responder (HR): weight loss greater than 15%, and low-responder (LR): weight loss less than 15%).

RESULTS

The mean age was 64.2 (7.5) years. After 6 months of treatment, a weight loss of 10.2% (8.2-13.8) was observed. There was a significant increase in vitamin D (HR: 21.8% (36.2) vs. LR: 22.7% (36.9), p=0.93) and CrossLaps (HR: 26.8% (19.5-35.2)) vs. LR: 13.3% (-6.1 to 27.9), p=0.01). The loss of more than 15% of initial body weight was an independent risk factor for an increase in CrossLaps (OR: 4.22 (1.1-16.8), p=0.04).

CONCLUSIONS

In postmenopausal obese women, weight loss was associated with an increase in the biochemical parameters of bone resorption. The increase in resorption parameters was related to the magnitude of weight loss.

Dietary-fat effect of the rs10830963 polymorphism in MTNR1B on insulin resistance in response to 3 months weight-loss diets

BACKGROUND & AIMS

The risk allele (G) of rs10830963 in the melatonin receptor 1 B (MTNR1B) gene presents an association with obesity. We study the effect of this SNP on cardiovascular risk factors and weight loss secondary to 2hypocaloric diets.

METHODS

361 obese subjects were randomly allocated during 3 months (Diet M - high monounsaturated fat hypocaloric diet vs. Diet P - high polyunsaturated fat hypocaloric diet). Anthropometric parameters, fasting blood glucose, C-reactive protein (CRP), insulin concentration, insulin resistance (HOMA-IR), lipid profile and adipocytokines levels were measured. Genotype of MTNR1B gene polymorphism (rs10830963) was evaluated.

RESULTS

All anthropometric parameters, systolic blood pressure and leptin levels decreased in all subjects after both diets. This improvement of anthropometric parameters was higher in non G allele carriers than G allele carriers. After dietary intervention with Diet M, (CC vs. CG + GG); total cholesterol (delta: -10.4 ± 2.1mg/dl vs. -6.4 ± 1.2mg/dl: P <.05), LDL-cholesterol (delta:-7.1 ± 0.9mg/dl vs. -2.8 ± 0.8mg/dl: P <.05), insulin (delta:-3.0 ± 0.8 UI/L vs. -2.0 ± 1.0 UI/L: P<.05) and HOMA-IR (delta:-3.4 ± 1.0 units vs. -2.9 ± 0.9 units: P<.05) improved in no G allele carriers. After Diet P, in the group of subjects without G allele CC, insulin levels (delta: -2.9 ± 1.0 UI/L vs. -0.6 ± 0.2 UI/L: P <.05) and HOMA-IR (delta (CC vs. CG + GG): -0.8 ± 0.2 units vs. -0.4 ± 0.3 units: P <.05) decreased, too.

CONCLUSIONS

Our study detected a relationship of rs10830963 MTNR1B SNP with body weight loss and insulin resistance modification induced by 2different hypocaloric. Only monounsaturated enriched hypocaloric diet and in no-G allele carriers showed a significant effect on lipoproteins.

a low fat hypocaloric diets in obese human subjects

BACKGROUND & AIMS

A common G-to-A transition located 75 base pairs upstream (rs670) from transcription start site of the APOA1 gene has been related with some metabolic parameters. Our aim was to analyze the effects of rs670 APOA1 gene polymorphism on lipid profile and metabolic changes after two different hypocaloric diets.

METHODS

282 obese subjects were randomly allocated during 12 weeks (Diet HF - high fat diet vs. Diet LF - low fat diet). Anthropometric and biochemical status were evaluated.

RESULTS

Body mass index, weight, fat mass, waist circumference, systolic blood pressure, leptin levels and waist circumference decreased in all patients in average after both diets. In A allele carriers after 12 weeks with both diets, insulin levels (Delta diet HF: -5.3 + 1.2 UI/L; P = 0.02 and Delta diet LF: -5.8 + 1.3 UI/L; P = 0.02) and HOMA-IR (Delta diet HF: -2.9 + 0.8 units; P = 0.01 and Delta diet LF: -2.2 + 0.9 units; P = 0.03) improved in a significant way. With the low fat diet, A allele carriers showed a statistical improvement in HDL-cholesterol levels (Delta: 4 + 1 mg/dl; P = 0.03).

CONCLUSIONS

Our study showed the association of rs670 ApoA1 polymorphism with a decrease of insulin resistance induced by both diets and provided additional evidence on HDL-cholesterol increase after a LF hypocaloric diet in A allele carriers.

Common polymorphism in the cannabinoid receptor gene type 2 (CB2R) rs3123554 are associated with metabolic changes after two different hypocaloric diets with different dietary fatty profiles

BACKGROUND

The role of CB2R gene variants on weight loss after a dietary intervention has been investigated in few studies.

OBJECTIVE

We evaluate the effect of this genetic variant (rs3123554) of CB2R gene on cardiovascular risk factors and weight loss secondary to high monounsaturated fat vs a high polyunsaturated fat hypocaloric diets.

DESIGN

A Caucasian population of 362 obese patients was enrolled. Patients were randomly allocated during 3 months to one of two diets (Diet P high polyunsaturated (PUFAs) fat hypocaloric diet vs, Diet M high monounsaturated (MUFAs) fat hypocaloric diet).

RESULTS

In both genotype groups (GG vs GA+AA), body weight, body mass index (BMI), fat mass, waist circumference and systolic blood pressure decreased after diet P and M. Body weight, BMI, fat mass and waist circumference were higher in A allele carriers than non A allele carriers. The improvement of these parameters was higher in non A allele carriers than A allele carriers. In non A allele carriers with both diets, the decrease of total cholesterol, LDL-cholesterol, insulin and HOMA-IR was higher than A allele carriers after both diets. After diet P, triglyceride levels decrease in non A allele carriers.

CONCLUSION

Our data suggest that carriers of the minor allele of rs3123554 variant of CB2R gene lose less body weight during to different hypocaloric diets with different fatty acid. Moreover, non A-allele carriers showed a better response of LDL-cholesterol, HOMA-IR and insulin levels than A-carriers with both hypocaloric diets.

Obesity Related Metabolic Disorders and Risk of Renal Disease: Impact of Hypocaloric Diet and Avena Sativa Supplement

BACKGROUND

The recognition of the complications of obesity in various organs and systems should make clinicians and dietitians aware of the importance of early strategies to fight obesity in all age groups.

AIM

The objective of this study was to evaluate the early effect of using Avena sativa (oat) flour supplement compared to a hypocaloric diet in the management of obesity-related metabolic disorders.

MATERIAL AND METHODS

Snack was prepared from wholemeal wheat flour (100% extraction) and oat flour. Chemical analysis of the raw materials and the formulae was carried out. 106 obese women with their mean body mass index were 37.73 ± 0.56 kg/m2 volunteered for 8 weeks period. They were divided into two groups; group (A), consumed hypocaloric diet supplemented by the prepared snack, while group (B) subjects followed the low caloric balanced diet. All patients were monitored clinically, anthropometrically, dietary 24 h recall and biochemically.

RESULT

Data demonstrated significantly decreased in the mean levels of the anthropometric parameters. Group (A) showed a higher decrease in the waist circumference, WHR, body fat% and SBP; while in group (B) weight, BMI, chest circumference and DBP were the most affected parameters. The reduction in the biochemical parameters was higher in the group (A). At the baseline, high values of cystatin-C were found in both groups which may indicate early renal injury. At the end of the study, a significant reduction of the cystatin concentration was observed among both groups (-24.54 & -12.23%).

CONCLUSION

The healthy effect of the dietary oat supplement on the reduction of central obesity, percentage body fat and different metabolic disorders criteria was confirmed than with hypocaloric diet.

Changes in lysophospholipids and liver status after weight loss: the RESMENA study

Background

Obesity and comorbidities such as non-alcoholic fatty liver disease (NAFLD) are major public health burdens. Alterations in lipid metabolism are involved in hepatic diseases. The objective of this study was to assess the influence of weight loss on lysophospholipid (LP) metabolism and liver status in obese subjects as well as to provide new evidence regarding the interaction of LP metabolism as a key factor in the onset and management of obesity-related diseases such as liver damage.

Methods

Thirty-three subjects from the RESMENA (Reduction of Metabolic Syndrome in Navarra, NCT01087086) study were selected based on their Fatty Liver Index (FLI). Plasma lipid species (lysophosphatidilcholine: LPC, lysophosphatidilethanolamines: LPE and lysophosphatidylinositols: LPI specifically) were determined by LC-MS, while waist circumference (WC) and other non-invasive liver markers such as, FLI and BAAT scores as well as dietary records, anthropometrical measurements, body composition by DXA and other metabolic determinants were analyzed before and after a six-month hypocaloric nutritional intervention.

Results

Computed Z-scores of total LP (LPC, LPE, and LPI) were significantly decreased after 6-months of following a hypocaloric diet. Specifically, LPC14:0, LPC15:0, LPC16:1, LPC18:4, LPC20:4, showed clear relationships with weight loss. Changes in FLI score, WC and BAAT score revealed associations with general changes in LPC score. Interestingly the BAAT score was statistically associated with the LPC score after adjustment for weight loss.

Conclusion

The lipidomic LPC profile analysis revealed a generalized decrease in circulating lysophospholipids after weight loss. The involvement of particular LP in liver metabolism and obesity merit further attention, as some of these specific non-invasive liver markers were reduced independently of weight loss.

Trial registration

NCT01087086. Registered 15 March 2010, retrospectively registry.

Effect of transcranial direct current stimulation associated with hypocaloric diet on weight loss and metabolic profile in overweight or obesity: study protocol for a double-blind, randomized controlled clinical trial

BACKGROUND

Dietary interventions have limited success in promoting sustainable weight loss; new treatments allowing better compliance with hypocaloric diets should be developed. The aim of this trial is to describe the effects of a protocol combining repetitive active transcranial direct current stimulation (tDCS) with a hypocaloric diet on weight loss and food consumption in overweight or obese adults.

METHODS/DESIGN

Overweight or obese adults between 20 and 50 years of age with stable weight over the last 4 months will be selected for a 4-week randomized clinical trial of fixed-dose tDCS (20 sessions; 5 consecutive weekdays/wk, 2 mA, 20 minutes) over the right dorsolateral prefrontal cortex associated with a weight loss diet. The subjects will be randomly assigned in a 1:1 ratio and stratified by sex to active tDCS + diet or sham tDCS + diet. The study will be conducted at the Endocrine and Metabolism Unit of the Hospital de Clínicas de Porto Alegre, Brazil. The primary outcome is weight loss. Energy and macronutrient consumption, as well as adherence to the diet, will be assessed using 3-day weighed dietary records. Changes in blood glucose and plasma insulin will be assessed, and participants will complete self-report questionnaires to assess changes in mood and food behavior. All analyses will be done on a per-protocol and intention-to-treat basis.

DISCUSSION

This study explores the potential role of tDCS as an adjunctive treatment with a hypocaloric diet for obesity management.

TRIAL REGISTRATION

ClinicalTrials.gov , NCT02683902 . Registered on 11 January 2016.

Effects of polymorphism rs3123554 in the cannabinoid receptor gene type 2 (CB2R) on metabolic and adiposity parameters after weight loss with two hypocaloric diets

BACKGROUND

The role of CB2R gene variants on weight loss after a dietary intervention remained unclear.

OBJECTIVE

Our aim was to analyze the effects of rs3123554 of CB2R receptor gene on metabolic and adiposity parameters after two different hypocaloric diets in obese subjects.

DESIGN

A Caucasian population of 280 obese patients was enrolled. Patients were randomly allocated during 3 months to one of two diets (Diet I - moderate in carbohydrate. Vs Diet II - normal in carbohydrate).

RESULTS

In both genotype groups (GG vs GA + AA), body weight, body mass index (BMI), fat mass, waist circumference and systolic blood pressure decreased after diet I and II. The decrease of these parameters was higher in non A allele carriers than A allele carriers. Pre- and post-dietary intervention, body weight, BMI, fat mass and waist circumference were higher in A allele carriers than non A allele carriers. In non A allele carriers, the decrease of glucose, insulin, HOMA-IR and Interleukin-6 levels was higher than A allele carriers after both diets.

CONCLUSION

Carriers of the minor allele of rs3123554 variant of CB2R gene loose less body weight during two different hypocaloric diets. The improvement of metabolic parameters was better in no A allele carriers than A allele carriers.

RS 10767664 gene variant in Brain Derived Neurotrophic Factor (BDNF) affect metabolic changes and insulin resistance after a standard hypocaloric diet

BACKGROUND

Role of BDNF variants on change in body weight and cardiovascular risk factors after weight loss remains unclear in obese patients.

OBJECTIVE

Our aim was to analyze the effects of rs10767664 BDNF gene polymorphism on body weight, cardiovascular risk factors and serum adipokine levels after a standard hypocaloric diet in obese subjects.

DESIGN

A Caucasian population of 80 obese patients was analyzed before and after 3months on a standard hypocaloric diet.

RESULTS

Fifty patients (62.5%) had the genotype AA and 30 (37.5%) subjects had the next genotypes; AT (25 patients, 31.3%) or TT (5 study subjects, 6.3%) (second group). In non T allele carriers, the decreases in weight-3.4±2.9kg (T allele group -1.7±2.0kg:p=0.01), BMI -1.5±0.2kg (T allele group -1.2±0.5kg:p=0.02), fat mass-2.3±1.1kg (T allele group -1.7±0.9kg:p=0.009), waist circumference-3.8±2.4cm (T allele group -2.1±3.1cm:p=0.008), triglycerides -13.2±7.5mg/dl (T allele group +2.8±1.2mg/dl:p=0.02), insulin -2.1±1.9mUI/L (T allele group -0.3±1.0mUI/L:p=0.01), HOMA-IR -0.9±0.4 (T allele group -0.1±0.8:p=0.01) and leptin -10.1±9.5ng/dl (T allele group -3.1±0.2ng/dl:p=0.01) were higher than T allele carriers.

CONCLUSION

rs10767664 variant of BDNF gene modify anthropometric and biochemical changes after weight loss with a hypocaloric diet.

Modifications of serum levels of omentin-1 and other cardiovascular risk factors following weight loss secondary to a Mediterranean hypocaloric diet

BACKGROUND & AIMS

Omentin-1 might play a role on insulin resistance, dyslipidemia and obesity. The aim of this investigation was to evaluate the influence of weight loss on omentin-1 concentrations after a hypocaloric diet with Mediterranean pattern.

METHODS

A Caucasian sample of 67 obese patients was analyzed before and after 3 months on a hypocaloric diet. Anthropometric parameters, blood pressure, fasting blood glucose, C-reactive protein (CRP), fasting insulin, insulin resistance (HOMA-IR), lipid concentrations and omentin-1 were measured.

RESULTS

Sixty-seven obese subjects were enrolled in the study. The mean age was 48.3 ± 8.0 years (range: 25-66) and the mean BMI 34.5 ± 4.8 kg/m² (range: 30.2-40.8). Gender distribution was 50 females (74.6%) and 17 males (25.4%). After dietary intervention and in males and females; body mass index, weight, fat mass, waist circumference, blood pressure, glucose, LDL cholesterol, insulin and HOMA-IR decreased. Omentin-1 levels increase after dietary intervention (males vs females) (delta basal vs 3 months: 10.0 ± 3.8 ng/dl: p = 0.01 vs 9.9 ± 4.1 ng/dl; p = 0.03). In the multiple regression analysis adjusted for age and sex; BMI and insulin remained independently associated with baseline and post-treatment levels of omentin-1.

CONCLUSIONS

Our investigation showed a significant increase in omentin-1 levels after weight loss secondary to a hypocaloric diet with a Mediterranean pattern.

Association of the rs10830963 polymorphism in melatonin receptor type 1B (MTNR1B) with metabolic response after weight loss secondary to a hypocaloric diet based in Mediterranean style

BACKGROUND & AIMS

Some genetic variants within MTNR1B were related with fasting glucose levels or the increased prevalence of diabetes mellitus and obesity. The aims of the present investigation were to determine the influence of rs10830963 MTNR1B variant in relation to body weight loss, insulin resistance and adipokine levels in response to a hypocaloric diet with Mediterranean pattern.

METHODS

A Caucasian population of 80 obese patients was studied before and after 12 weeks on a hypocaloric diet. Body weight, fat mass, waist circumference, blood pressure, fasting blood glucose, C-reactive protein (CRP), insulin concentration, insulin resistance (HOMA-IR), lipoprotein levels and adipocytokines levels (leptin, adiponectin and resistin) were measured. Genotype of MTNR1B gene single nucleotide polymorphism (rs10830963) was evaluated.

RESULTS

In total, 44 patients (55%) had the genotype CC, 27 patients CG (33.8%) and 9 patients GG (11.2%). With the dietary intervention body mass index, weight, fat mass, systolic blood pressure, leptin levels and waist circumference decreased in both groups. There were no significant differences between gender groups on the reported effects in each genotype group. However, the improvement of anthropometric parameters was higher in subjects with CC genotype than (GC + GG) genotype. After dietary intervention and in males with CC genotype, insulin levels (-5.3 ± 4.8 UI/L vs 1.2 ± 4.1 UI/L; p < 0.05) and HOMA-IR (-1.4 ± 2.1 units vs 0.4 ± 2.0 units; p < 0.05) decreased. In the group of females with CC genotype, insulin levels (-3.5 ± 2.1 UI/L vs. -1.4 ± 2.2 UI/L: p < 0.05) and HOMA-IR (-1.4 ± 1.2 units vs. -0.1 ± 1.3 units: p < 0.05) decreased, too. However, these parameters remained unchanged in (GC + GG) group. Fasting glucose levels were higher in patients in (GC + GG).

CONCLUSIONS

This study showed the association of rs10830963 MTNR1B single nucleotide polymorphism with body weight loss and changes in fasting insulin levels and HOMA-IR in obese subjects.

The Effect of Dried Glycyrrhiza Glabra L. Extract on Obesity Management with Regard to PPAR-γ2 (Pro12Ala) Gene Polymorphism in Obese Subjects Following an Energy Restricted Diet

Purpose: Obesity is a multi-factorial health problem which results from the interaction of environmental and genetic factors. The aim of the present study was to determine the effects of dried licorice extract with a calorie restricted diet on anthropometric indices and insulin resistance with nutrigenetic approach. Methods: For this pilot, double-blind, placebo-controlled randomized clinical trial, 72 eligible subjects were randomly allocated to Licorice or placebo group. They received a low-calorie diet either with a 1.5 g/day of Licorice extract or placebo for 8 weeks. Results: There were no significant differences in anthropometric indices and dietary intake in genotype subgroups at the baseline. Findings indicated that supplementation with Licorice extract did not change anthropometric indices and biochemical parameters significantly compared to a hypocaloric diet alone. However, from the nutrigenetic point of view, significant changes in anthropometric indices and QUICKI were observed in the Pro12Pro genotypes compared to the Pro12Ala at the end of the study (p<0.05 in all variables). Moreover, no interactive effect of the Licorice supplement and Pro12Ala genotype was found. Conclusion: In obese subjects, the Pro/Pro polymorphism of the PPAR-γ2 gene seems to induce favourable effects on obesity management. Further studies are needed to clarify whether PPAR-γ2 gene polymorphisms or other obesity genes can affect responses to obesity treatment.

The rs10401670 variant in resistin gene improved insulin resistance response and metabolic parameters secondaries to weight loss after a hypocaloric diet

BACKGROUND

The SNP 3'UTR C/T (rs10401670), it is a polymorphism that has been associated with diabetes mellitus and it has been scarcely studied before. As far as we know, no studies on interaction among diet intervention, rs10401670 variant of RETN and metabolic response has been realized.

OBJECTIVE

Our aim was to analyze the effects of the rs10401670 RETN gene polymorphism on insulin resistance response and metabolic changes secondary to weight loss after 3 months of a hypocaloric diet in adults obese patients without diabetes mellitus.

DESIGN

A Caucasian population of 135 obese patients without diabetes mellitus was analyzed. Before and after 3 months on a low fat hypocaloric diet, an anthropometric evaluation, an assessment of nutritional intake and a biochemical analysis were performed. The statistical analysis was performed for the combined CT and TT as a group (minor allele group) and wild type CC as second group (major allele group) (dominant model).

RESULTS

Forty nine patients (36.3%) had the genotype CC (major allele group) and 86 (63.7%) patients had the next genotypes; CT (67 patients, 49.6%) or TT (19 patients, 14.1%) (minor allele group). After dietary treatment and in major allele group, weight, BMI, fat mass, systolic blood pressure and waist circumference decreases were similar than minor allele group. In T allele carriers, fasting plasma glucose, insulin, HOMA-IR, total cholesterol and LDL cholesterol levels decreased significantly. In non T allele carriers and after dietary treatment, only LDL cholesterol and total cholesterol decreased. In non T Allele carriers, the decrease in total cholesterol was -15.1 ± 18.3 mg/dl (decrease in T Allele carriers -18.3 ± 15.7 mg/dl: p > 0.05), LDL-cholesterol was -14.3 ± 18.5 mg/dl (decrease in T Allele carriers -17.3 ± 10.1 mg/dl:p > 0.05), fasting glucose plasma -2.2 ± 1.5 mg/dL (decrease in T Allele carriers -4.8 ± 1.2 mg/dL: p = 0.02), insulin -1.1 ± 2.0 mUI/L (decrease in T Allele carriers -6.3 ± 1.9 mUI/L: p = 0.001) and HOMA-IR -0.2 ± 1.0 (decrease in T Allele carriers -1.8 ± 1.4: p = 0.005). Leptin levels decrease in both genotypes after dietary treatment (-21.1 ± 8.5 ng/dL in nonT Allele carriers vs -16.2 ± 10.2 ng/dL in T Allele carriers:p > 0.05). Resistin remained unchanged in both groups.

CONCLUSION

In our study in non-diabetic obese subjects, we describe an association of rs10401670T allele with a better metabolic response (glucose, insulin and HOMA-IR) secondary to weight loss with a hypocaloric diet.

Evaluation of Hypocaloric Diet With Protein Supplementation in Middle-Aged Sarcopenic Obese Women: A Pilot Study

OBJECTIVE

The aim of this study was to evaluate the efficacy of a nutritional program, which is characterized by a different modulation of proteins, in adult patients with sarcopenic obesity.

METHODS

We studied 18 obese women aged 41-74 years. Obesity was diagnosed as fat mass > 34.8% and sarcopenia was defined when lean body mass was <90% of the subject's ideal fat free mass. All subjects were randomly assigned to different nutritional interventions: Hypocaloric diet plus placebo (A) and hypocaloric high-protein diet (1.2-1.4 g / kg body weight reference / day) (B). Anthropometric measurements, body composition, resting energy expenditure, handgrip test, Short Physical Performance Battery (SPPB), and SF-36 questionnaire were evaluated at baseline and after 4 months.

RESULTS

Weight significantly decreased in both groups. Women with high-protein diet preserved lean body mass compared to low-calorie diet and improved significantly muscle strength; SPPB score did not change in both groups. SF-36 test showed a significant change for general health after 4 months in group B.

CONCLUSIONS

In our study, sarcopenic obese patients with high-protein diet showed an improvement in muscle strength. Furthermore, dietary protein enrichment may represent a protection from the risk of sarcopenia following a hypocaloric diet.

Effects of a high-protein/low-carbohydrate versus a standard hypocaloric diet on adipocytokine levels and cardiovascular risk factors during 9 months, role of rs6923761 gene variant of glucagon-like peptide 1 receptor

BACKGROUND

The role of GLP-1 R variants on body weight response after dietary intervention is unclear.

OBJECTIVE

The aim was to investigate the role of this polymorphism on cardiovascular risk factors, adipokine levels and weight loss secondary to a high-protein/low-carbohydrate vs. standard hypocaloric diets during 9 months.

DESIGN

211 obese subjects were randomly allocated to one of these two diets for a period of 9 months; diet HP (high protein/low carbohydrate) and diet S (standard).

RESULTS

Ninety-four patients (44.5%) had the genotype GG (wild group) and 117 (55.5%) patients had the next genotypes; GA (89 patients, 42.2%) or AA (28 patients, 13.3%) (mutant group). With both diets and in both genotype groups, body mass index, weight, fat mass, waist circumference and systolic blood pressure decreased. Anthropometric parameters were higher in non-A allele carriers than A allele carriers. With diet HP in both genotypes, LDL cholesterol, total cholesterol, leptin, insulin levels and HOMA-R decreased. With the diet S and only in wild genotype, the same parameters decreased, too.

CONCLUSION

Our data showed a lack of association of rs6923761 GLP-1 R polymorphism with weight loss. Better anthropometric parameters in obese subjects with the mutant allele (A) of rs6923761 GLP-1 R polymorphism were observed. Total cholesterol, LDL cholesterol, insulin levels and HOMA-R decreased in all patients with both diets, although A allele carriers treated with standard diet did not show these changes.

Association between circulating irisin levels and the promotion of insulin resistance during the weight maintenance period after a dietary weight-lowering program in obese patients

OBJECTIVE

Weight regain is associated with the promotion of insulin resistance. The newly discovered myokine irisin, which was proposed to be involved in the management of insulin sensitivity, could play a role in this process. This study aimed to investigate the association between irisin and reduced insulin sensitivity induced by weight regain.

MATERIALS/METHODS

Insulin sensitivity was evaluated according to the homeostasis model assessment of insulin resistance (HOMA-IR) in 136 obese patients who followed an eight-week hypocaloric diet (30% reduced energy expenditure) to lose weight and was re-evaluated four or six months after treatment. Irisin plasma levels, as well as the levels of leptin, adiponectin, ghrelin and TNF-α, were quantified in a sub-cohort (n=73) from the initially studied patients at baseline (T0), at the diet endpoint (T1) and after the follow-up period (T2).

RESULTS

After a successful dietary intervention to lose weight, 50% of the patients who regained the lost weight during the follow-up period were categorized as insulin resistant (HOMA-IR≥2.5) compared with only 25% of patients who maintained the weight loss (p=0.018). Importantly, in addition to the well-studied hormones leptin and adiponectin, irisin plasma levels were statistically associated with several risk factors for insulin resistance. Indeed, the increased risk of insulin resistance during the follow-up period was related to high irisin levels at baseline (odds ratio=4.2; p=0.039).

CONCLUSIONS

Circulating irisin predicts the insulin resistance onset in association with weight regain. Therefore, irisin could be secreted as an adaptive response to counteract the deleterious effect of excess adiposity on glucose homeostasis.

[Effect of a hypocaloric diet in the oxidative stress in obese subjects without prescription of exercise and antioxidants]

BACKGROUND AND OBJECTIVE

Obesity is characterized by a generalized increase of adipose tissue, high production of adipocytokines and presence of oxidative systemic stress. The objective of this study was to evaluate the changes generated in the oxidative stress and anthropometric parameters in obese subjects by the prescription of a hypocaloric diet in combination with moderate aerobic exercise and supplementation with antioxidants.

PATIENTS AND METHODS

Oxidative damage was determined in the plasma from 30 normal weight and 30 obese subjects. Three groups of treatment were established: Hypocaloric diet (HD), HD plus moderate aerobic exercise (HDE) and HDE plus antioxidants (DHEA). Biomarkers of oxidative stress (thiobarbituric acid reactive substances [TBARS], carbonyl groups, dityrosine) and anthropometric parameters were determined.

RESULTS

Higher values of biomarkers of oxidative damage were observed in obese (TBARS 13.74 ± 1.2 μM; carbonyl groups 0.89 ± 0.04 nmol of osazone/mg of protein; dityrosine 478.9 ± 27.4 RFU/mg of protein) in comparison to normal weight subjects (TBARS 7.08 ± 0.8 μM; carbonyl groups 0.65 ± 0.04 nmol of osazone/mg of protein; dityrosine 126.3 ± 12.6 RFU/mg of protein), thus showing the presence of an oxidative damage. The prescription of HD decreased the oxidative damage and anthropometric parameters in the obese subjects. We did not observe additional benefit effects on these determinations with HDE or HDEA treatments.

CONCLUSIONS

We demonstrated that an HD decreases the oxidative damage in obese subjects. Oxidative stress is an important factor in the development of comorbidity in obesity. Therefore, the prescription of a HD could be a key issue in the treatment of the disease.

Potential role of meal frequency as a strategy for weight loss and health in overweight or obese adults

Improved dietary strategies for weight loss are necessary to decrease metabolic disease risk in overweight or obese adults. Varying meal frequency (MF; i.e., increasing or decreasing eating occasions beyond the traditional pattern of three meals daily) has been thought to have an influence on body weight regulation, hunger control, and blood markers of health. It is common practice for weight management clinicians to recommend increasing MF as a strategy for weight management and to improve metabolic parameters. However, limited research exists investigating the effect of MF during controlled hypocaloric dietary interventions. Furthermore, MF literature often speculates with regard to efficacy of MF treatments based on research using normal weight, overweight/obese, or some combination, where much diversity exists within these various populations. In this review, we suggest that normal-weight and overweight/obese populations, as well as free-living versus investigator-controlled research trials, should be studied independently. Therefore, the objective of the present review is to survey the literature to assess whether the alteration of MF influences body weight regulation, hunger control, and/or blood markers of health in overweight/obese participants undergoing a controlled hypocaloric diet to induce weight loss. Findings of this review indicate that there is uncertainty in the literature when interpreting the optimal MF for obesity treatment, where reduced MF may even show more favorable lipid profiles in obese individuals compared with increased MF. Furthermore, the simple relationship of comparing MF with body fatness or body mass index should also consider whether eating frequency is associated with other healthy factors (e.g., increased physical activity).

Role of G308 promoter variant of tumor necrosis factor alpha gene on weight loss and metabolic parameters after a high monounsaturated versus a high polyunsaturated fat hypocaloric diets

BACKGROUND AND OBJECTIVE

The aim of our study was to investigate the influence of G-308 promoter variant of the tumor necrosis factor (TNF) alpha gene on metabolic changes and weight loss secondary to a high monounsaturated fat vs a high polyunsaturated fat hypocaloric diet in obese subjects.

PATIENTS AND METHOD

A sample of 261 obese subjects were enrolled in a consecutive prospective way, from May 2011 to July 2012 in a tertiary hospital. In the basal visit, patients were randomly allocated during 3 months to Diet M (high monounsaturated fat hypocaloric diet) and Diet P (high polyunsaturated fat hypocaloric diet).

RESULTS

One hundred and ninety seven patients (73.2%) had the genotype G-308G and 64 (26.8%) patients had the genotype G-308A. There were no significant differences between the effects (on weight, body mass index (BMI), waist circumference, fat mass) in either genotype group with both diets. With the diet type P and in genotype G-308G, glucose levels (-6.7(22.1)mg/dl vs -3.7(2.2)mg/dl: p = 0.02), HOMA-R (-0.6(2.1)units vs -0.26(3.1)units: p = 0.01), insulin levels (-1.7(6.6)UI/L vs -0.6(7.1)UI/L: p = 0.009), total cholesterol levels (-15.3(31.1)mg/dl vs -8.4(22.1)mg/dl: p = 0.01), LDL cholesterol levels (-10.7(28.1)mg/dl vs -3.8(21.1)mg/dl: p = 0.008) and triglycerides (-12.1(52.1)mg/dl vs -6.6(43.1)mg/dl: p = 0.02) decreased.

CONCLUSION

Carriers of the G-308G promoter variant of TNF alpha gene have a better metabolic response than A-308 obese with a high polyunsaturated fat hypocaloric diet.