A Trial of the Ideal Protein System Versus Low Fat Diet for Weight Loss (RENEWAL)

This study will examine whether, compared to a standard, low-fat, calorie-restricted diet intervention, the clinic-supported Ideal Protein weight loss method will result in greater weight loss and improvement in cardiometabolic risk factors over 3 months among obese adults with cardiovascular disease (CVD) risk factors.

Study Overview

• Status: Completed
• Conditions: Weight Loss
• Intervention / Treatment: Behavioral: Ideal Protein Weight Loss Method; Behavioral: Standard Weight Loss

Detailed Description

Restricting total calorie intake is emphasized in the 2013 American Heart Association/ American College of Cardiology/ The Obesity Society Guideline (AHA/ACC/TOS) for the Management of Overweight and Obesity in Adults for its effectiveness at reducing body weight and decreasing cardiometabolic risk factors. An implication of this focus on total quantity of calories consumed is that macronutrient composition of dietary intake and its effects on the hormonal milieu that regulates adipose accumulation in the human body do not play a significant role in weight loss. Such recommendations and the results of limited previous studies have led to the advice that all weight loss diets regardless of macronutrient composition will produce the same degree of weight loss if adherence to the diet is similar. In contrast, our previous studies have shown that despite comparable adherence to dietary goals, participants losing weight on a moderately carbohydrate-restricted, adequate protein regimen have improved cardiometabolic indicators as compared to those restricting fat. The RENEWAL trial will provide unique data on the efficacy of the Ideal Protein method (moderate carbohydrate restriction and adequate protein) for weight loss and improvement in cardiometabolic risk factors. The interventions will include a significant proportion of African-Americans, a group with very high rates of obesity which is often under-represented in trials examining the effects of weight loss diets. Findings from this trial may offer new evidence for the recommendation of specific macronutrient and behavioral approaches to the reduction of cardiometabolic risk factors.

• Study Type: Interventional
• Enrollment (Actual): 192
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Louisiana
    • Bogalusa, Louisiana, United States, 70427
      • Bogalusa Heart Study Clinic

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 22 years to 79 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

1. All participants will be obese. Obesity will be defined as BMI ≥ 30 kg/m2 at the baseline study visit. An upper limit of BMI will be set at 49 kg/m2 to include a wide range of obese men and women with a reasonable probability of losing weight in the context of a dietary behavioral intervention.
2. Participants must have at least one co-morbid condition that increases risk of cardiovascular disease (history of CVD, type II diabetes mellitus, fasting plasma glucose>100 mg/dL, metabolic syndrome as defined by ATP III criteria, hypertension, hyperlipidemia, WC>40 in among men or >35 in among women).
3. All potential participants must be willing and able to provide informed consent.

Exclusion Criteria:

1. History of any bariatric surgery, including gastric banding, Roux-en-Y and duodenal switch with biliopancreatic diversion procedures, vertical banded gastroplasty, etc.
2. Currently on a diet or using prescription weight loss medications, and/or experienced weight loss >15 pounds within 6 months of study entry.
3. Regular use of alcohol >3 beverages per day or 21 beverages per week (1 standard beverage = 350 mL of 5% alcohol beer, or 150 mL of 12% wine, or 45 mL of 80-proof distilled spirits), amphetamines, cocaine, heroin, or marijuana over past 6 months.
4. Past or present history of eating disorder (including anorexia, bulimia or binge eating disorder) or severe/untreated psychiatric illness which may affect participation in study interventions.
5. Strict dietary concerns (e.g., vegetarian or kosher diet, significant nut or multiple food allergies). This is an exclusion because participant may not be able to fully participate in the intervention.
6. For women, current pregnancy or breastfeeding or plans to become pregnant during the study period. This is an exclusion because weight loss is contraindicated during pregnancy.
7. Plans to move out of the study area (>1 hour from study site) or difficulty to come to the study site. This is an exclusion because these conditions may interfere with the ability to fully participate in and complete the study.
8. Participation of another household member in the study; employees or persons living with employees of the study. This is an exclusion because randomization of more than one participant in a household to differing diets may cause conflict within a household and limit engagement in the intervention. Employees of the study are excluded due to potential conflicts of interest and knowledge of study assignments.
9. Participation in other lifestyle intervention trials currently. This is an exclusion because interference with ability to determine whether study interventions are responsible for outcomes.
10. Medical condition in which a carbohydrate restricted diet may not be advised (eg. severe renal impairment, osteoporosis, untreated thyroid disease, frequent gout attacks, Type I diabetes). This is an exclusion because participant may not be able to fully participate in the intervention.
11. Hospitalization for a CVD event such as myocardial infarction, stroke, TIA, coronary revascularization, heart failure, peripheral artery disease, or unstable angina within the last 6 weeks or unstable coronary artery disease. Major new medical illness including renal disease requiring dialysis, a life-threatening illness with life expectancy less than six months, or cancer requiring chemotherapy or radiation treatment in the previous two years. [NOTE: potential participants may still qualify if they have had treatment for an early stage cancer in the past two years and the prognosis is excellent.] This is an exclusion because these conditions may interfere with the ability to fully participate in and complete the study.
12. MMSE score < 23 or dementia. This is an exclusion because it may interfere with the ability to fully participate in the study.
13. Non-English speaking, a visual impairment or a hearing impairment that interferes with study participation. This is an exclusion criterion because these potential participants may not be able to participate fully in the intervention.
14. In addition to the above criteria, investigator discretion will be used to determine if the trial is unsafe or not a good fit for the potential participant.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Ideal Protein Weight Loss Protocol; This arm will follow the Ideal Protein method as documented in the Ideal Protein Clinic Manual and in the Ideal Protein Coaches Manual.	Behavioral: Ideal Protein Weight Loss Method; An initial visit will take place in which each participant assigned to the experimental group will complete a health profile questionnaire.The Ideal Protein method will be explained and the participant will be weighed, measured and given diet related informational materials. A staff member will assist the participant with the selection of foods and snacks to ensure adequate quantity for the week. Weekly follow-up visits of 15 minutes duration will be implemented with a telephone follow-up occurring during the first 4 days after the initial appointment. For 12 weeks Ideal Protein foods that are of the appropriate composition and quantity will be provided at weekly or twice monthly intervals as included in the diet. Dietary supplements will be provided (multivitamin, calcium/magnesium, potassium, omega-3, and Ideal Salt substitute).
Active Comparator: Standard Weight Loss; This arm utilizes evidence-based, low fat, low calorie strategies that have been shown to be effective for long-term weight loss and weight loss maintenance.	Behavioral: Standard Weight Loss; This arm utilizes evidence-based strategies that have been shown to be effective for long-term weight loss and weight loss maintenance (including behavioral techniques, diet modification, and social support) consistent with the 2013 AHA/ACC/TOS Guideline for the Management of Overweight and Obesity in Adults. Participants in this arm will have an initial one hour consultation with a trained interventionist, where the fat goal and calorie restriction goal are explained. For 12 weeks low-fat reduced calorie foods that are of appropriate composition and quantity will be provided at weekly or twice monthly intervals as included in the diet. Dietary supplements will be provided (multivitamin, calcium/magnesium, potassium, omega-3, and Ideal Salt substitute).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in weight	Change in weight at follow-up	Baseline and three months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Body Composition	Change in waist and hip circumference	Baseline and three months
Body Composition	Change in lean and fat mass	Baseline and three months
Lipid parameters	Change in lipid parameters	Baseline and three months
Fasting glucose	Change in fasting glucose	Baseline and three months
Continuously measured glucose	Change in continuously measured glucose	Baseline and three months
Systolic Blood Pressure	Change in systolic blood pressure	Baseline and three months
Diastolic Blood Pressure	Change in systolic blood pressure	Baseline and three months
Appetite	Change in appetite as measured by self-report questionnaires	Baseline and three months
Satiety	Change in satiety as measured by self-report questionnaires	Baseline and three months

Collaborators and Investigators

• Sponsor: Tulane University
• Collaborators: Ideal Protein

Publications and helpful links

General Publications

• Fernandez CA, Potts K, Bazzano LA. Effect of ideal protein versus low-fat diet for weight loss: A randomized controlled trial. Obes Sci Pract. 2021 Oct 15;8(3):299-307. doi: 10.1002/osp4.567. eCollection 2022 Jun.

Study record dates

Study Major Dates

• Study Start (Actual): May 23, 2018
• Primary Completion (Actual): September 30, 2020
• Study Completion (Actual): September 30, 2020

Study Registration Dates

• First Submitted: April 23, 2018
• First Submitted That Met QC Criteria: April 23, 2018
• First Posted (Actual): May 4, 2018

Study Record Updates

• Last Update Posted (Actual): November 22, 2024
• Last Update Submitted That Met QC Criteria: November 20, 2024
• Last Verified: November 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Body Weight Changes; Weight Loss; Body Weight
• Other Study ID Numbers: 2017-917

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