Effects of Different Dietary Interventions on Abdominal Fat Components and Cardiometabolic Parameters.

Effects of Different Dietary Interventions on Abdominal Fat Components and Cardiometabolic Parameters: a Randomized Clinical Trial.

The study aims to evaluate the impact of different dietary interventions on abdominal fat components and cardiometabolic parameters. This is a randomized clinical trial study conducted in overweight adults, selected by voluntary adherence, in an outpatient clinic of a cardiology hospital. The sample was calculated based on data from a study with the Brazilian population, with the sample size calculated as a function of a mean difference (d) in visceral adipose tissue (VAT) after the interventions, standard deviation (s) and a significance level of 5% (z). To correct eventual losses, the number was increased by 20%. Four dietary interventions will be applied in the 6-month period: group with calorie restriction and balanced distribution of macronutrients (group 1); group with calorie restriction and low-carbohydrate diet (group 2); group with calorie restriction and low-fat diet (group 3) and group with collective nutritional guidance (group 4). Patients will be followed up monthly to assess weight loss, analyze adherence to the diet therapy plan, reinforce nutritional guidelines and monitor anthropometric measurements and abdominal adipose tissue. The evaluation of VAT and subcutaneous adipose tissue (SAT) by ultrasonography will be performed at baseline and after 6 months of intervention. The present study is expected to clarify the effects that different dietary interventions produce over 6 months on abdominal fat deposits and cardiometabolic parameters.

Study Overview

• Status: Enrolling by invitation
• Conditions: Cardiac Disease; Metabolic Disease; Abdominal Obesity; Cardiometabolic Syndrome
• Intervention / Treatment: Behavioral: Calorie restriction and balanced distribution of macronutrients; Behavioral: Calorie restriction and low-carbohydrate diet; Behavioral: Calorie restriction and low-fat diet; Behavioral: Collective nutritional guidance

Detailed Description

The study aims to evaluate the impact of different dietary interventions on abdominal fat components and cardiometabolic parameters. This is a randomized clinical trial study conducted in overweight adults, selected by voluntary adherence, in an outpatient clinic of a cardiology hospital. The sample will take place by voluntary adherence, after evaluation of the eligibility criteria and signing of the Free and Informed Consent Form. The sample was calculated based on data from a study with the Brazilian population , with the sample size calculated calculated as a function of a mean difference between the initial visceral adipose tissue (VAT) concentration and after dietary intervention, obtaining a minimum sample of 100 individuals. To correct eventual losses, this number was increased by 20%, totaling a sample n of 120 individuals. Four dietary interventions will be applied in the 6-month period: group with calorie restriction and balanced distribution of macronutrients (group 1), considering a progressive reduction of 500 to 1000 calories from the usual food intake or the recommendation of 20 calories/kg of current weight/day and distribution of macronutrients: 5% of carbohydrates, 2% of proteins and 3% of fats; group with calorie restriction and low-carbohydrate diet (group 2), considering a reduction in carbohydrate consumption and an increase in fat and protein intake, with the following proportions: 45% fat, 20% protein and 35% carbohydrate ; group with calorie restriction and low-fat diet (group 3), considering a restriction of fat consumption and an increase in carbohydrate consumption, with the following proportions: 20% fat, 15% protein and 65% carbohydrate and group with collective nutritional guidance (group 4), considering the recommendations of the Food Guide for the Brazilian Population. Patients will be followed up monthly to assess weight loss, analyze adherence to the diet therapy plan, reinforce nutritional guidelines and monitor anthropometric measurements and abdominal adipose tissue. The evaluation of VAT and subcutaneous adipose tissue (SAT) by ultrasonography will be performed at baseline and after 6 months of intervention. The weight loss will be evaluated as a percentage (%), based on the difference between the weight at the outcome and the weight at baseline. The following parameters will be monitored: blood pressure, biochemical tests (leptin, adiponectin, fasting glucose, fasting insulin, glycated hemoglobin, triglycerides, total cholesterol and fractions, and C-reactive protein), anthropometric measurements (weight, height, waist circumference, and abdominal circumference), demographic variables (age, gender, schooling) and socioeconomic status. Data will be analyzed using the Statistical Package for Social Sciences - version 13.0 . In the description of the proportions, the binomial distribution will be approximated to the normal distribution by the 95% confidence interval. The proportions will be compared by the Chi-square test. Student's t-tests for paired or Wilcoxon samples will be used to compare VAT, SAT, weight, BMI and biochemical parameters before and after the intervention of each group. To compare the changes in VAT, SAT, anthropometric and biochemical parameters between the intervention groups, the one way or Kruskal Wallis ANOVA test will be used. Statistical significance will be established when a p<0.05 value. The present study is expected to clarify the effects that different dietary interventions produce over 6 months on abdominal fat deposits and cardiometabolic parameters.

• Study Type: Interventional
• Enrollment (Estimated): 100
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Brazil
  • PE
    • Recife, PE, Brazil, 51021120
      • Isa Galvao Rodrigues

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Individuals of both sexes, aged ≥20 years, Body Mass Index (BMI) ≥25kg/m², attended at the general Nutrition outpatient clinic of a public university hospital reference in cardiology.

Exclusion Criteria:

• Malnourished and eutrophic individuals;
• Individuals with liver disease and/or splenomegaly, ascites, or with recent abdominal surgery;
• Pregnant women and women who had children up to 6 months prior to the survey screening;
• Individuals with consumptive diseases whose weight loss may be a consequence;
• Individuals with hypothyroidism or hyperthyroidism, on pharmacological therapy for weight loss and/or on hormone therapy;
• Individuals with mental or psychological illnesses that may make it difficult to understand dietary guidelines;
• Individuals with physical limitations that made it impossible to carry out the anthropometric and abdominal adipose tissue evaluations.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Dietary intervention 1; Calorie restriction and balanced distribution of macronutrients	Behavioral: Calorie restriction and balanced distribution of macronutrients; Progressive reduction of 500 to 1000 calories from the usual food intake or the recommendation of 20 calories/kg of current weight/day and distribution of macronutrients: 5% of carbohydrates, 2% of proteins and 3% of fats
Experimental: Dietary intervention 2; Calorie restriction and low-carbohydrate diet	Behavioral: Calorie restriction and low-carbohydrate diet; Reduction in carbohydrate consumption and an increase in fat and protein intake, with the following proportions: 45% fat, 20% protein and 35% carbohydrate
Experimental: Dietary intervention 3; Calorie restriction and low-fat diet	Behavioral: Calorie restriction and low-fat diet; Restriction of fat consumption and an increase in carbohydrate consumption, with the following proportions: 20% fat, 15% protein and 65% carbohydrate
Experimental: Dietary intervention 4; Collective nutritional guidance	Behavioral: Collective nutritional guidance; Recommendations of the Food Guide for the Brazilian Population: limitation of the intake of foods with high energy density from fats and simple carbohydrates; substitution of saturated fats for unsaturated fats; exclusion of trans fat from the diet; increasing fruit and vegetable consumption to a daily minimum of 400g; increased consumption of high-fibre foods and limiting the consumption of sugars and salt.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Thickness, measured in centimeters, of visceral adipose tissue	The effects that different dietary interventions produce on visceral adipose tissue thickness ( measured en centimeters) will be evaluated	6 months
Weight loss measured in kilograms	The effect of different dietary interventions produce on weight, measured in kilograms, will be evaluated	6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Serum levels of fasting glucose	The effects that different dietary interventions produce in serum levels of fasting glucose ( in mg/dl).), will be evaluated.	6 months
Serum levels of Insulin	The effects that different dietary interventions produce in serum levels of insulin in Microinternational Unit per Milliliter (μIU/mL)), will be evaluated.	6 months
Serum levels Triglycerides	The effects that different dietary interventions produce in serum levels of triglycerides (in mg/dl), ), will be evaluated.	6 months
Serum levels Lipid profile	The effects that different dietary interventions produce in serum levels of cholesterol (in mg/dl) , low-density lipoprotein cholesterol (LDL-C) ( in mg/dl), high-density lipoprotein cholesterol (HDL-C) ( in mg/dl), ), will be evaluated.	6 months
Serum levels C-reactive protein (hs-CRP)	The effects that different dietary interventions produce in serum levels of C-reactive protein (hs-CRP) (in mg/dl)), will be evaluated.	6 months

Collaborators and Investigators

• Sponsor: University of Pernambuco
• Collaborators: Universidade Federal de Pernambuco

Publications and helpful links

General Publications

• de Souza RJ, Bray GA, Carey VJ, Hall KD, LeBoff MS, Loria CM, Laranjo NM, Sacks FM, Smith SR. Effects of 4 weight-loss diets differing in fat, protein, and carbohydrate on fat mass, lean mass, visceral adipose tissue, and hepatic fat: results from the POUNDS LOST trial. Am J Clin Nutr. 2012 Mar;95(3):614-25. doi: 10.3945/ajcn.111.026328. Epub 2012 Jan 18.

Study record dates

Study Major Dates

• Study Start (Actual): August 23, 2021
• Primary Completion (Actual): December 26, 2023
• Study Completion (Estimated): August 1, 2024

Study Registration Dates

• First Submitted: January 17, 2024
• First Submitted That Met QC Criteria: March 18, 2024
• First Posted (Actual): March 20, 2024

Study Record Updates

• Last Update Posted (Actual): March 20, 2024
• Last Update Submitted That Met QC Criteria: March 18, 2024
• Last Verified: March 1, 2024

More Information

Terms related to this study

• Keywords: Cardiometabolic Risk Factors; Abdominal Obesity; Dietetic interventions
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Glucose Metabolism Disorders; Overnutrition; Nutrition Disorders; Overweight; Body Weight; Insulin Resistance; Hyperinsulinism; Obesity; Heart Diseases; Metabolic Syndrome; Metabolic Diseases; Obesity, Abdominal
• Other Study ID Numbers: 4659262

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No