Does a Low-Fat Vegetarian Diet Improve Insulin Resistance in Individuals With Type 2 Diabetes?

The aim of the study is to evaluate the effect of experimental (vegetarian) diet compared to conventional diet with similar caloric restriction on insulin resistance, body weight and body composition in type 2 diabetic patients after 3 month diet program and additional 3 month diet program combined with intensive exercise.

Hypothesis: Greater improvement in insulin resistance, greater weight loss without compromising the body composition (subjects will lose fat preferentially to lean body mass) and differences in the fatty tissue metabolism will be found in the experimental (vegetarian) group compared to the control (conventional diet) group despite the similar advise on caloric restriction in both diets. The differences between the two groups will increase after an intensive physical exercise program.

Study Overview

• Status: Completed
• Conditions: Insulin Resistance
• Intervention / Treatment: Other: diabetic diet following the DNSG guidelines; Other: low-fat vegetarian diet

Detailed Description

Open randomized study. Individuals with type 2 diabetes (n=60) will be recruited through newspaper advertisements and through advertisements in the hospital. They will be randomly assigned to a low-fat vegetarian diet or a diet following the guidelines of the Study Group on Diabetes and Nutrition of the European Association for the Study of Diabetes (DNSG) (21) with similar caloric restriction (-500 kcal/d). The participants will be followed for 12 weeks and then for another 12 weeks with the addition of intensive physical exercise. All meals during the 6 months will be provided.

• Study Type: Interventional
• Enrollment (Actual): 70
• Phase: Phase 1

Contacts and Locations

Study Locations

• Czech Republic
  • Prague, Czech Republic
    • Institute for Clinical and Experimental Medicine

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 30 years to 70 years (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

1. Individuals with type 2 diabetes as defined by the criteria of the American Diabetes Association and recognized by WHO, Expert Committee on the Diagnosis and Classification of Diabetes Mellitus (19,20)
2. Concurrent T2 DM therapy: The use of oral hypoglycemic medication stable for the last 3 months
3. HbA1c ≥ 4 and ≤ 9.0 % (IFCC) ~ ≥ 6.0 and ≤ 11 % (DCCT)
4. Men and women who are 30 to 70 years of age
5. Body Mass Index (kg/m2) between 25 and 53
6. Informed Consent: a signed and dated written consent obtained from the subject before any procedures are performed
7. Willing to change dietary habits and to follow the prescribed diet and exercise program

Exclusion Criteria:

1. Current alcohol or drug abuse
2. Pregnancy, lactating
3. Unstable medical status
4. Diagnosis of Type 1 diabetes mellitus
5. Significant weight gain or loss (defined as ≥ 10% of total body weight) within the past 3 months prior to screening.
6. Pacemaker or metal in the body.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: TREATMENT
• Allocation: RANDOMIZED
• Interventional Model: PARALLEL

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
ACTIVE_COMPARATOR: Active Comparator; Diabetic diet following the DNSG guidelines	Other: diabetic diet following the DNSG guidelines; The DNSG diet consists of 15-20% protein, ≤7% saturated fat, 60-70% carbohydrate and monounsaturated fats, cholesterol ≤200 mg/day, fiber content 20-30g/day.
EXPERIMENTAL: Experimental; Low-fat vegetarian diet	Other: low-fat vegetarian diet; The low-fat vegetarian diet (~10% of energy from fat, 15% protein, and 75% carbohydrate, fiber content 40-50 g/day) consists of vegetables, fruits, grains, legumes and small amounts of nuts. Participants will be asked to avoid animal products and added fats and to favor low-glycemic index foods, such as beans and green vegetables.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Insulin resistance	6 months

Secondary Outcome Measures

Outcome Measure	Time Frame
Visceral to subcutaneous fatty tissue ratio	6 months

Collaborators and Investigators

• Sponsor: Institute for Clinical and Experimental Medicine
• Investigators: Principal Investigator: Terezie Pelikanova, MD, PhD, Head of the Diabetes Center

Publications and helpful links

General Publications

• Kahleova H, Tonstad S, Rosmus J, Fisar P, Mari A, Hill M, Pelikanova T. The effect of a vegetarian versus conventional hypocaloric diet on serum concentrations of persistent organic pollutants in patients with type 2 diabetes. Nutr Metab Cardiovasc Dis. 2016 May;26(5):430-8. doi: 10.1016/j.numecd.2016.01.008. Epub 2016 Jan 28.
• Kahleova H, Matoulek M, Malinska H, Oliyarnik O, Kazdova L, Neskudla T, Skoch A, Hajek M, Hill M, Kahle M, Pelikanova T. Vegetarian diet improves insulin resistance and oxidative stress markers more than conventional diet in subjects with Type 2 diabetes. Diabet Med. 2011 May;28(5):549-59. doi: 10.1111/j.1464-5491.2010.03209.x.

Study record dates

Study Major Dates

• Study Start: July 1, 2008
• Primary Completion (ACTUAL): November 1, 2008
• Study Completion (ACTUAL): March 1, 2009

Study Registration Dates

• First Submitted: July 15, 2008
• First Submitted That Met QC Criteria: April 15, 2009
• First Posted (ESTIMATE): April 17, 2009

Study Record Updates

• Last Update Posted (ESTIMATE): April 17, 2009
• Last Update Submitted That Met QC Criteria: April 15, 2009
• Last Verified: April 1, 2009

More Information

Terms related to this study

• Keywords: insulin resistance; vegetarian diet
• Additional Relevant MeSH Terms: Glucose Metabolism Disorders; Metabolic Diseases; Hyperinsulinism; Insulin Resistance
• Other Study ID Numbers: 785206