Role of whole grains versus fruits and vegetables in reducing subclinical inflammation and promoting gastrointestinal health in individuals affected by overweight and obesity: a randomized controlled trial.
Nutrition journal. 2018;17(1):72
Plain language summary
Poor diet is the leading risk factor for premature death and disability in the United States. Poor diets lead to metabolic syndrome and its associated diseases such as heart disease and diabetes. The purpose of this study was to determine the impact of increasing intake of wholegrains or fruit and vegetables against a typical Western diet on inflammatory makers and gut microbiota composition. The study was a randomized, parallel arm feeding trial which enrolled fifty-two participants. The subjects were randomized into three groups (control, wholegrains, and fruit and vegetables). Results indicate that the wholegrain and fruit and vegetable diets had significant positive impacts on inflammatory markers. Interestingly, while both treatment groups decreased inflammatory markers, each decreased a different biomarker. The treatments induced individualised changes in microbiota composition such that treatment group differences were not identified. Authors conclude that wholegrain and fruit and vegetable diets have a positive impact on metabolic health in individuals affected by overweight or obesity.
BACKGROUND Whole grains (WG) and fruits and vegetables (FV) have been shown to reduce the risk of metabolic disease, possibly via modulation of the gut microbiota. The purpose of this study was to determine the impact of increasing intake of either WG or FV on inflammatory markers and gut microbiota composition. METHODS A randomized parallel arm feeding trial was completed on forty-nine subjects with overweight or obesity and low intakes of FV and WG. Individuals were randomized into three groups (3 servings/d provided): WG, FV, and a control (refined grains). Stool and blood samples were collected at the beginning of the study and after 6 weeks. Inflammatory markers [tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), lipopolysaccharide binding protein (LBP), and high sensitivity C-reactive protein (hs-CRP)] were measured. Stool sample analysis included short/branched chain fatty acids (S/BCFA) and microbiota composition. RESULTS There was a significant decrease in LBP for participants on the WG (- 0.2 μg/mL, p = 0.02) and FV (- 0.2 μg/mL, p = 0.005) diets, with no change in those on the control diet (0.1 μg/mL, p = 0.08). The FV diet induced a significant change in IL-6 (- 1.5 pg/mL, p = 0.006), but no significant change was observed for the other treatments (control, - 0.009 pg/mL, p = 0.99; WG, - 0.29, p = 0.68). The WG diet resulted in a significant decrease in TNF-α (- 3.7 pg/mL; p < 0.001), whereas no significant effects were found for those on the other diets (control, - 0.6 pg/mL, p = 0.6; FV, - 1.4 pg/mL, p = 0.2). The treatments induced individualized changes in microbiota composition such that treatment group differences were not identified, except for a significant increase in α-diversity in the FV group. The proportions of Clostridiales (Firmicutes phylum) at baseline were correlated with the magnitude of change in LBP during the study. CONCLUSIONS These data demonstrate that WG and FV intake can have positive effects on metabolic health; however, different markers of inflammation were reduced on each diet suggesting that the anti-inflammatory effects were facilitated via different mechanisms. The anti-inflammatory effects were not related to changes in gut microbiota composition during the intervention, but were correlated with microbiota composition at baseline. TRIAL REGISTRATION ClinicalTrials.gov , NCT02602496 , Nov 4, 2017.
Comparison of low calorie high protein and low calorie standard protein diet on waist circumference of adults with visceral obesity and weight cycling.
BMC research notes. 2018;11(1):674
Plain language summary
Obesity has become one of the world’s biggest health problem. Obese individuals with a history of repeated weight loss and regain (called weight cycling) have a higher risk of developing chronic disease and increased fat mass in every cycle. The objective of the study was to evaluate the effect of a low calorie high protein diet compared to a low calorie standard protein diet on waist circumference in adults with visceral obesity. The open, randomised clinical trial recruited 61 obese subjects who are older than 20 years of age and had a history of weight cycling. Participants were randomly assigned to one of the two diet groups; high protein or standard protein. Results showed that following a low-calorie diet resulted in waist circumference reduction thus reducing visceral fat. However, protein composition in the diet plan did not affect waist circumference reduction. Authors conclude that calorie restricted diets could be suggested in the treatment of visceral obesity. Macronutrient composition can be adjusted to meet the patient’s individual needs.
OBJECTIVES Many individuals with visceral obesity who previously had succeeded in reducing body weight regain and this loss-gain cycle repeats several times which is called as weight cycling. We aimed to evaluate the effect of a low calorie high protein diet (HP) compared to a low calorie standard protein diet (SP) on waist circumference of visceral obese adults with history of weight cycling. RESULTS In this open-randomized clinical trial, participants were asked to follow dietary plan with reduction in daily caloric intake ranging from 500 to 1000 kcal from usual daily amount with minimum daily amount of 1000 kcal for 8 weeks and were divided in two groups: HP group with protein as 22-30% total calorie intake; and SP group with protein as 12-20% total calorie intake. There was a statistically significant difference (P < 0.001) between waist circumference before and after the dietary intervention among both groups. Meanwhile, there was no statistically significant difference in the mean reduction of waist circumference between HP and SP groups (P = 0.073). Taken together, the protein proportion does not significantly affected waist circumference. Trial registration ClinicalTrials.gov NCT03374150, 11 December 2017.
Acute Endothelial Benefits of Fat Restriction over Carbohydrate Restriction in Type 2 Diabetes Mellitus: Beyond Carbs and Fats.
Plain language summary
The control of type 2 diabetes mellitus has become a global challenge. Cardiovascular disease is a major cause of mortality in type 2 diabetes. The aim of the study is to examine and compare the effect of a hypocaloric very low carbohydrate diet versus hypocaloric low-fat diet on vascular function and visceral adipose tissue in type 2 diabetic patients. The study is a randomised parallel group intervention study with adult type 2 diabetes patients with an age range between 42 and 76 years. Results show that both dietary strategies effectively reduced body weight, total adipose tissue, visceral adipose tissue and lipid accumulation in the liver. However, participants following the low-fat diet experienced greater vascular function enhancements. Authors conclude that low-fat diet elicited advantageous effects on vascular function in patients with type 2 diabetes.
BACKGROUND Cardiovascular diseases (CVD) are the major cause of mortality in type 2 diabetes patients (T2DM). The causes are embedded in a complex interplay between excess body fat, insulin resistance and serum lipid anomalies. Endothelial homeostasis is strongly affected by this pathogenic network. Even though metabolic changes and weight loss improve vascular endothelial function, the effect of different dietary approaches is still uncertain for type 2 diabetes patients. OBJECTIVE We aimed to compare the acute effects of a hypocaloric very low carbohydrate (VLC) diet versus a hypocaloric low fat (LF) diet on flow mediated dilation (FMD), intrahepatic lipid (IHL) accumulation and visceral adipose tissue as independent risk factors of CVD in T2DM patients. DESIGN 36 T2DM patients (age 63 ± 8 years, 60% females) were randomly assigned to the VLC diet (4⁻10% of total energy intake (E)) or to the LF diet (<30% E) for 3 weeks. Endothelial function was assessed by the flow mediated dilation (FMD) method. Adipose tissue depots and IHL were determined by magnetic resonance. RESULTS Both dietary strategies reduced body weight, body fat content and IHL. Unexpectedly, the LF group experienced significantly greater enhancement of FMD, compared to the VLC group. The FMD showed a positive correlation with protein intake and fat intake in the LF group, while it revealed a negative correlation with protein intake in the VLC diet group. CONCLUSIONS Reduction of total and hepatic adiposity was shown to be successful using either the VLC or LF hypocaloric diets, however, improvements in FMD may be related to the interplay of fat and protein intake.
The Effect of Low-Carbohydrate Diet on Glycemic Control in Patients with Type 2 Diabetes Mellitus.
Plain language summary
Dietary intervention is a strategy to manage diabetes mellitus, as it can reduce the burden on islet cells and thus improve blood glucose levels, lipid profiles, and cognitive status. The aim of the study was to find out the effectiveness of the ‘six-point formula’ and the effects of a low-fat diet and low-carbohydrate diet on hyperglycaemia. The study is a prospective, single-blind randomized controlled trial which recruited 56 participants with type 2 diabetes mellitus. The participants were randomly allocated to receive either a low-fat diet or a low-carbohydrate diet. Results show that HbA1c levels (the average blood glucose levels in the last 2 – 3 months) in low-carbohydrate diet decreased significantly compared to the low-fat diet. The body mass index and the total cholesterol levels of the participants following the low-carbohydrate diet also decreased. Authors conclude that a low-carbohydrate diet can improve blood glucose, regulate blood lipids, reduce body mass index and decrease insulin doses more than a low-fat diet in Chinese patients with type 2 diabetes mellitus.
OBJECTIVE In China, a low-fat diet (LFD) is mainly recommended to help improve blood glucose levels in patients with type 2 diabetes mellitus (T2DM). However, a low-carbohydrate diet (LCD) has been shown to be effective in improving blood glucose levels in America and England. A few studies, primarily randomized controlled trials, have been reported in China as well. METHOD Firstly, we designed two 'six-point formula' methods, which met the requirements of LCD and LFD, respectively. Fifty-six T2DM patients were recruited and randomly allocated to the LCD group ( = 28) and the LFD group ( = 28). The LCD group received education about LCD's six-point formula, while the LFD group received education about LFD's six-point formula. The follow-up time was three months. The indicators for glycemic control and other metabolic parameters were collected and compared between the two groups. RESULTS Forty-nine patients completed the study. The proportions of calories from three macronutrients the patients consumed met the requirements of LCD and LFD. Compared to the LFD group, there was a greater decrease in HbA1c level in the LCD group (-0.63% vs. -0.31%, < 0.05). The dosages of insulin and fasting blood glucoses (FBG) in the third month were lower than those at baseline in both groups. Compared with baseline values, body mass index (BMI) and total cholesterol (TC) in the LCD group were significantly reduced in the third month ( < 0.05); however, there were no statistically significant differences in the LFD group. CONCLUSIONS LCD can improve blood glucose more than LFD in Chinese patients with T2DM. It can also regulate blood lipid, reduce BMI, and decrease insulin dose in patients with T2DM. In addition, the six-point formula is feasible, easily operable, and a practical educational diet for Chinese patients with T2DM.
A comparative controlled trial comparing the effects of yoga and walking for overweight and obese adults.
Medical science monitor : international medical journal of experimental and clinical research. 2014;20:894-904
Plain language summary
Walking and yoga are types of exercise that may be useful for weight loss. The aim of this study was to compare the effects of yoga and walking on the biochemistry, body composition, balance and strength in overweight people. 68 Indian adults who were overweight or obese were allocated to either yoga or walking twice a day for 15 days. Both groups were given the same plant-based diet providing 1,650 kcal/day Both groups showed similar and significant decreases in body mass index (BMI), waist and hip circumference, lean mass, body water and total cholesterol over the 15 days. The yoga group increased serum leptin and decreased LDL cholesterol. The walking group decreased serum adiponectin and triglycerides. Since there was no control group, it was not possible to attribute the changes to the yoga or walking, rather than the diet. The authors concluded that both yoga and walking improved anthropometric variables and serum lipid profile in overweight and obese people, and that these interventions may be useful in treating obesity.
BACKGROUND Walking and yoga have been independently evaluated for weight control; however, there are very few studies comparing the 2 with randomization. MATERIAL AND METHODS The present study compared the effects of 90 minutes/day for 15 days of supervised yoga or supervised walking on: (i) related biochemistry, (ii) anthropometric variables, (iii) body composition, (iv) postural stability, and (v) bilateral hand grip strength in overweight and obese persons. Sixty-eight participants, of whom 5 were overweight (BMI ≥25 kg/m2) and 63 were obese (BMI ≥30 kg/m2; group mean age ±S.D., 36.4±11.2 years; 35 females), were randomized as 2 groups - (i) a yoga group and (ii) a walking group - given the same diet. RESULTS All differences were pre-post changes within each group. Both groups showed a significant (p<0.05; repeated measures ANOVA, post-hoc analyses) decrease in: BMI, waist circumference, hip circumference, lean mass, body water, and total cholesterol. The yoga group increased serum leptin (p<0.01) and decreased LDL cholesterol (p<0.05). The walking group decreased serum adiponectin (p<0.05) and triglycerides (p<0.05). CONCLUSIONS Both yoga and walking improved anthropometric variables and serum lipid profile in overweight and obese persons. The possible implications are discussed.