Effect of a Vegan Diet Versus a Mediterranean Diet. Assessing Health Outcomes

NCT ID: NCT06008886

Last Updated: 2023-11-28

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

COMPLETED

Clinical Phase

NA

Total Enrollment

14 participants

Study Classification

INTERVENTIONAL

Study Start Date

2023-06-19

Study Completion Date

2023-09-04

Brief Summary

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This study aimed to evaluate the effect of a vegan diet (supplemented with vitamin B12) and an mediterranean diet on performance, cardiorespiratory fitness, metabolic health, immune status, and environmental impact in healthy adults.

Detailed Description

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OMNIVEG is a controlled crossover trial. Initially, registered dietitians conducted an assessment of participants' lifestyles in a preliminary session. Qualified nutritionists then developed personalized diets for each participant in accordance with the recommendations of the International Society of Sports Nutrition (ISSN). These diets followed specific guidelines, including a daily intake of 3-5 g of carbohydrates per kilogram of body weight, 1.4-2.0 g of protein per kilogram of body weight, and 0.5-1.5 g of fat per kilogram of body weight.

Both the mediterranean diet and vegan diets prescribed to the participants were isocaloric, with similar distributions of macronutrients. The primary difference between the two interventions was the source of food: the vegan diet exclusively comprised plant-based foods, while the omnivorous diet included foods of both animal and plant sources. In the case of the omnivorous diet, 60% of the total protein intake was derived from animal sources (mainly from fish, white meat, low-fat dairy and eggs).

As part of the vegan diet, participants were instructed to take 1000 µg of cyanocobalamin (a form of vitamin B12) twice a week from Harrison Sport Nutrition, Granada, Spain. This supplementation aimed to ensure adequate vitamin B12 intake, which is essential for individuals following a vegan diet.

Throughout the study period, participants were advised to maintain their initial physical exercise frequency and volume to maintain consistency and avoid confounding variables. To ensure standardized measurements, all tests were conducted in the same laboratory, employing identical testing devices, and supervised by the same group of researchers. This approach aimed to minimize experimental variability and improve the reliability of the study's results.

Conditions

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Cardiometabolic Syndrome

Study Design

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Allocation Method

NON_RANDOMIZED

Intervention Model

CROSSOVER

Primary Study Purpose

PREVENTION

Blinding Strategy

NONE

Study Groups

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Vegan diet

Vegan diet all foods included were of plant sources. During the vegan diet, the participants took 1000 µg of cyanocobalamin twice a week (Harrison Sport Nutrition, Granada, Spain)

Group Type EXPERIMENTAL

Vegan diet

Intervention Type BEHAVIORAL

Normocaloric diet based solely on foods of plant sources.

Mediterranean diet

In the case of the mediterranean diet, foods of animal sources were also included (animal protein accounted for 60% of total protein intake). In this diet there was a predominance of plant foods; moderate to low consumption of fish, white meat, low-fat dairy and eggs; and very low consumption of red and processed meats, butter, full-fat dairy and sweets.

Group Type ACTIVE_COMPARATOR

Mediterranean diet

Intervention Type BEHAVIORAL

Diet with a predominance of plant foods fruits, vegetables, whole grains, nuts and legumes); moderate to low consumption of fish, white meat, low-fat dairy and eggs; and very low consumption of red and processed meats, butter, full-fat dairy and sweets.

Interventions

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Vegan diet

Normocaloric diet based solely on foods of plant sources.

Intervention Type BEHAVIORAL

Mediterranean diet

Diet with a predominance of plant foods fruits, vegetables, whole grains, nuts and legumes); moderate to low consumption of fish, white meat, low-fat dairy and eggs; and very low consumption of red and processed meats, butter, full-fat dairy and sweets.

Intervention Type BEHAVIORAL

Eligibility Criteria

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Inclusion Criteria

* Men.
* Aged between 18-40 years.
* Physically active according to the recommendations of the World Health Organization (WHO).
* Body Mass Index (BMI) between 18.5-24.9 kg/m2.
* No tobacco use.
* No or low alcohol consumption and no orthopedic limitations that would interfere with the performance of the study tests.

Exclusion Criteria

* Chronic diseases that impair athletic performance (cardiovascular, metabolic, gastrointestinal, respiratory) within the last six months.
* Musculoskeletal disease within the last six months.
Minimum Eligible Age

18 Years

Maximum Eligible Age

40 Years

Eligible Sex

MALE

Accepts Healthy Volunteers

Yes

Sponsors

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Universidad Francisco de Vitoria

OTHER

Sponsor Role lead

Responsible Party

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Miguel López Moreno

Principal Investigator

Responsibility Role PRINCIPAL_INVESTIGATOR

Principal Investigators

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Miguel López Moreno, Phd

Role: PRINCIPAL_INVESTIGATOR

Universidad Francisco de Vitoria

Locations

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Francisco de Vitoria University

Madrid, , Spain

Site Status

Countries

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Spain

References

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Lopez-Moreno M, Fresan U, Del Coso J, Munoz A, Aguilar-Navarro M, Iglesias-Lopez MT, Amaro-Gahete FJ, Gutierrez-Hellin J. The OMNIVEG Study: Effects of Transitioning from a Traditional to a Vegan Mediterranean Diet on Fat Oxidation During Exercise. Nutrients. 2025 Jul 9;17(14):2274. doi: 10.3390/nu17142274.

Reference Type DERIVED
PMID: 40732902 (View on PubMed)

Lopez-Moreno M, Fresan U, Del Coso J, Aguilar-Navarro M, Iglesias Lopez MT, Pena-Fernandez J, Munoz A, Gutierrez-Hellin J. The OMNIVEG STUDY: Health outcomes of shifting from a traditional to a vegan Mediterranean diet in healthy men. A controlled crossover trial. Nutr Metab Cardiovasc Dis. 2024 Dec;34(12):2680-2689. doi: 10.1016/j.numecd.2024.08.008. Epub 2024 Aug 23.

Reference Type DERIVED
PMID: 39358106 (View on PubMed)

Other Identifiers

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20/2023

Identifier Type: -

Identifier Source: org_study_id