Monounsaturated fat-rich diet reduces body adiposity in women with obesity, but does not influence energy expenditure and substrate oxidation: a parallel randomized controlled clinical trial.

BACKGROUND: Obesity is an important and growing health problem whose treatment involves dietary changes. In this context, studying the role of macronutrients in weight loss is required in order to understand which strategies may be applied for weight loss. We aimed to evaluate the effects of diets rich in polyunsaturated (PUFAs) and monounsaturated fatty acids (MUFAs) on resting energy expenditure (REE), substrate oxidation, and weight loss in women with obesity. METHODS: Randomized, controlled, single blind, parallel-group clinical trial was conducted for 60 days. Participants (n = 32) were divided into three groups: G1= normocaloric PUFAs-rich diet (12% of total energy expenditure (TEE), 10% of n-6 and up to 2% of n-3); G2= normocaloric MUFAs-rich diet (15-20% TEE); and G3= maintenance of the usual diet. Anthropometric and metabolic variables (REE and substrate oxidation by indirect calorimetry) were evaluated. RESULTS: G2 decreased body weight (-1.92 ± 1.99 kg, P = 0.02), body mass index (BMI) (-0.69 ± 0.70 kg/m2; P = 0.02), waist circumference (WC) (-1.91 ± 1.82 cm; P = 0.02), and body fat (-1.14 ± 1.53 kg; P = 0.04). CONCLUSION: MUFAs-rich diet reduces body weight, BMI, body fat, and WC. CLINICAL TRIALS: NCT02656940. CLINICAL TRIAL REGISTRATION: Clinical Trials: NCT02656940.

Gut Microbiota Profile in Adults Undergoing Bariatric Surgery: A Systematic Review.

Gut microbiota (GM) after bariatric surgery (BS) has been considered as a factor associated with metabolic improvements and weight loss. In this systematic review, we evaluate changes in the GM, characterized by 16S rRNA and metagenomics techniques, in obese adults who received BS. The PubMed, Scopus, Web of Science, and LILACS databases were searched. Two independent reviewers analyzed articles published in the last ten years, using Rayyan QCRI. The initial search resulted in 1275 documents, and 18 clinical trials were included after the exclusion criteria were applied. The predominance of intestinal bacteria phyla varied among studies; however, most of them reported a greater amount of Bacteroidetes (B), Proteobacteria (P), and diversity (D) after BS. Firmicutes (F), B, and the (F/B) ratio was inconsistent, increasing or decreasing after Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) were conducted, compared to before surgery. There was a reduction in the relative proportion of F. Moreover, a higher proportion of Actinobacteria (A) was observed after RYGB was conducted. However, the same was not identified when SG procedures were applied. Genera abundance and bacteria predominance varied according to the surgical procedure, with limited data regarding the impact on phyla. The present study was approved by PROSPERO, under registration number CRD42020209509.

Modulation of the gut microbiota by probiotics and symbiotics is associated with changes in serum metabolite profile related to a decrease in inflammation and overall benefits to metabolic health: a double-blind randomized controlled clinical trial in women with obesity.

Modulation of the gut microbiota may help in treating obesity by improving host metabolic health. We aimed to evaluate the effects of probiotics or symbiotics on body weight and serum metabolite profile in women with obesity. A double-blind, parallel, randomized, controlled clinical trial was conducted with 32 adult women with body mass index ranging from 30 to 34.9 kg m-2. Volunteers followed a low-energy diet and were subjected to 8 weeks intervention: probiotic group (PG - Bifidobacterium lactis UBBLa-70, n = 10), symbiotic group (SG - Bifidobacterium lactis UBBLa-70 and fructooligosaccharide, n = 11), or control group (CG - placebo, n = 11). Analyses of anthropometric variables, gut microbiota and serum metabolites by 1H nuclear magnetic resonance (NMR) were performed at baseline and after the intervention. Multivariate statistics showed that all groups presented a decrease in glycerol and increase in arginine, glutamine and 2-oxoisovalerate. Therefore, a low-energy diet per se promoted changes in the metabolite profile related to decreased inflammation and positive effects on body weight. SG presented unique changes in metabolites (increase in pyruvate and alanine and decrease in citrate and BCAA). Negative correlations between arginine and glutamine with fat mass were observed in the SG. PG presented a decrease in 1H NMR lipid signals and negative correlation between Verrucomicrobia and Firmicutes with (CH2)n lipids. Both probiotics and symbiotics promoted changes in metabolites related to improved metabolic health. Specific metabolite changes following symbiotic intervention might suggest some advantage in providing Bifidobacterium lactis in combination with fructooligosaccharide in a low-energy diet, rather than probiotics or diet alone. Clinical trial: NCT02505854.

Effect of coconut oil on weight loss and metabolic parameters in men with obesity: a randomized controlled clinical trial.

Coconut oil appears to help in weight loss and improve metabolic parameters associated with obesity. We evaluate the influence of coconut oil on the body composition, lipid profile and glycemia in men with obesity. A controlled, randomized clinical trial was performed with 29 adult men affected by obesity. They were randomized between two groups receiving a daily intake of 1 tablespoon (12 mL) of extra virgin coconut oil (CO, n = 15) or soybean oil (SO, n = 14), and an isoenergetic balanced diet. The anthropometric profile, lipid profile and glycaemia were evaluated at the baseline and 45 days after intervention. The Mann-Whitney test was performed to compare the groups, and the Wilcoxon test was performed to compare the times. We considered a value of p < 0.05 as significant. There was no difference in anthropometric variables between the groups before and after intervention. The level of HDL cholesterol increased (3.67 ± 8.08 versus-3.79 ± 10.98, p = 0.02) and the TC/HDL cholesterol ratio decreased (-0.63 ± 0.82 versus 0.23 ± 0.80, p = 0.03) in the CO group, compared to the SO group. Coconut oil included in the isoenergetic balanced diet could increase HDL cholesterol and decrease the TC/HDL cholesterol ratio in men with obesity.

Profile of the gut microbiota of adults with obesity: a systematic review.

Recently, relationship between gut microbiota composition and development of obesity has been pointed. However, the gut microbiota composition of individual with obesity is not known yet. Therefore, this systematic review aimed to evaluate differences in profile of gut microbiota between individuals with obesity and individuals with normal weight. A search performed on August 2019 in the databases Pubmed, Scopus, Web of Science, Cochrane library, Lilacs and gray literature using the terms: "microbiota", "microbiome", "obesity", "obesity morbid", and "humans". Studies assessing the gut microbiota composition in adults with obesity and lean were included. Quality assessment was performed by Newcastle-Ottawa Quality Assessment Scale. Of the 12,496 studies, 32 were eligible and included in this review. Individuals with obesity have a greater Firmicutes/Bacteroidetes ratio, Firmicutes, Fusobacteria, Proteobacteria, Mollicutes, Lactobacillus (reuteri), and less Verrucomicrobia (Akkermansia muciniphila), Faecalibacterium (prausnitzii), Bacteroidetes, Methanobrevibacter smithii, Lactobacillus plantarum and paracasei. In addition, some bacteria had positive correlation and others negative correlation with obesity. Individuals with obesity showed profile of gut microbiota different than individual lean. These results may help in advances of the diagnosis and treatment of obesity.