Diet, VegetarianVeggieNutriNCT05408962
Nutritional and Metabolic Status of Vegetarian and Omnivorous Portuguese Adults
An observational study of Diet, Vegetarian and Diet, Vegan, run by Universidade do Porto at 1 site in Portugal.
Trial summary
Vegetarian diets have low environmental footprints and are potential solutions to address climate change and the 2030 Agenda on the Sustainable Development Goals. Currently, there is no information regarding the nutritional quality of vegetarian diets in Portugal. Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Diet, Vegetarian, Diet, Vegan, Nutritional Status
- What is being tested?
- Blood and urine collection, anthropometric analysis and answering to questionnaires
- How many people
- 400 participants
- Where
- 1 sitePortugal
- Study dates
- 1 Jul 2022to Jun 2024
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Participants will be recruited from general population. During advertisement, people will be invited to express their interest by filling in an online form which will include information about participation eligibility (eligibility criteria explained bellow). On recruitment day eligible participants will be asked to visit the recruitment center in fasting for blood and urine collection. In addition they will sign an informed consent, answer the lifestyle questionnaire and the Food Frequency Questionnaire and will be submitted to an anthropometric analysis and evaluation of blood preassure and heart rate.
Who may be able to join
- being a healthy adult
- being aged between 18 and 65 years
- having the reported dietary regimen for at least 1 year
Who cannot join
- being free from metabolic disorders
- being free from digestive disorders
- being free from renal disorders
- being free from haematological disorders
- being free from endocrine disorders
- being free from oncological diseases
- being free from food intolerances
- being free from eating disorders
Trial locations and contacts
1 site in 1 country.
Portugal1 site, 1 recruiting
- Recruiting
Faculty of Medicine (FMUP)
Porto, 4200-319
Elisa Keating, PhD, (+351) 225513624, keating@med.up.pt
Elisa Keating, PhD
About this study
Official title: VeggieNutri - Nutritional and Metabolic Status of Vegetarian and Omnivorous Portuguese Adults
Vegetarian diets have low environmental footprints and are potential solutions to address climate change and the 2030 Agenda on the Sustainable Development Goals. Currently, there is no information regarding the nutritional quality of vegetarian diets in Portugal. As the trend for vegetarianism increases in the country, the aim of this study is to examine and compare nutritional and metabolic outcomes among vegetarian and non-vegetarian populations. We aim to implement a cross-sectional study that includes a total of 400 (distributed among the three diferent groups of omnivorous, lacto-ovovegatarians and vegans) healthy Portuguese adults aged 18-64 years. Blood and urine samples will be collected. Participants will be assessed for blood pressure, anthropometric parameters, micronutrient status, blood lipids, glicaemia and insuline resistance and will complete a validated food frequency questionnaire as well as a sociodemographic and lifestyle questionnaire. Dietary and nutrient analysis will be conducted to assess diet quality and nutritional inadequacies. The current proposal provides an unique opportunity to characterize and compare different population groups clustered by dietary behaviour and provide evidence that help achieve healthy and sustainable diets in Portugal.
Read the detailed description
Plant-based diets have been proven to be sustainable and to have low environmental impact, highlighting the importance of promoting a dietary shift towards plant-based diets, with reduction in the consumption of animal food sources. In particular, vegetarian diets can refer to vegan (VEG) diets that completely exclude all animal derived foods or to lacto-ovo vegetarians (LOV) which include eggs and milk products and have low environmental footprint compared with omnivorous dietary patterns. Vegetarian diets are gaining popularity around the world. The reasons to follow a vegetarian diet are diverse and reported to be related to religion, animal welfare, sustainability and environmental reasons, as well as health related concerns. Literature has shown several health benefits of these diets. Regarding the efficiency of vegetarianism in promoting weight loss, studies in which a lacto-ovo vegetarian or vegan diet are administered to participants show that participants with previous plant based-diets that do not fully adhere to the prescribed weight loss diet loose more weight when compared to non-vegetarians. Moreover, vegan diets have been shown to be more effective in improving body composition and insulin resistance, when compared to an omnivorous diet. Despite the above referred evidence regarding beneficial effects on weight loss, some studies find no statistical differences on weight loss promoted by vegetarians, omnivorous or Mediterranean diets. Plant-based diets were also found to improve glycaemic control and insulin sensitivity. In fact, there is evidence on vegetarians having lower fasting insulin level and higher insulin sensitivity compared with matched omnivores. Moreover, these diets are considered to have a low inflammatory load to the point of being considered as an approach to lower inflammatory markers in patients with coronary artery disease. Nevertheless, since vegetarian diets are restrictive, they may give rise to nutritionally unbalanced regimens, particularly when adopted without nutritional counselling. In fact, several studies link vegetarian diets to poor nutritional status, including micronutrient deficiency. In this context, the great rise of vegetarian habits among Portuguese population, which are reported to have quadruplicated in the last 10 years, poses important health concerns. Nevertheless, data on the nutritional status characteristics and metabolic profile of such consumers and of the nutritional adequacy of their diet are scarce, particularly comparing with people with omnivorous dietary regimens.
So, it is crucial to assess the quality of vegetarian diets in the country, identifying clear health benefits and risks from a nutritional perspective. Considering the importance of promoting environmentally sustainable diets at national level and the lack of data regarding the diet quality of vegetarian diets in the country, we propose the implementation of the first cross-sectional study in the country to investigate and compare nutritional and health parameters among vegetarian and omnivorous populations. The current proposal provides an unique opportunity to characterize and compare different population groups clustered by dietary behaviour and identify potential risks and gaps to attain health and environmental goals, such as contributing to the Portugal commitments to achieve the 2030 Agenda on the Sustainable Development Goals.
- Conditions
- Diet, Vegetarian, Diet, Vegan, Nutritional Status, Metabolic Profile
- Being tested
- Blood and urine collection, anthropometric analysis and answering to questionnaires
- Keywords
- Vegetarian, Vegan, Diet quality, Metabolic profile, Nutritional status, Metabolic outcomes, Sustainable diets, Sustainability
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Blood and urine collection, anthropometric analysis and answering to questionnairesOther
During the visit to the recruitment center, participants will sign an informed consent. They will have to be in fasting condition for blood and urine collection. In addition they will answer the lifestyle questionnaire and the Food Frequency Questionnaire and will be submitted to an anthropometric analysis and evaluation of blood preassure and heart rate.
| Study group | Role | What they receive |
|---|---|---|
| OMNI - omnivorous | Healthy omnivorous adults with ages between 18 and 65 years and having the reported dietary regimen for at least 1 year, free from any chronic condition such as metabolic, digestive, renal, haematological, endocrine or oncological diseases and presenting no food intolerances or eating disorders. Receives: Other: Blood and urine collection, anthropometric analysis and answering to questionnaires | |
| LOV - lacto-ovovegetarians | Healthy lacto-ovovegetarians adults with ages between 18 and 65 years and having the reported dietary regimen for at least 1 year, free from any chronic condition such as metabolic, digestive, renal, haematological, endocrine or oncological diseases and presenting no food intolerances or eating disorders. Receives: Other: Blood and urine collection, anthropometric analysis and answering to questionnaires | |
| VEG - vegan | Healthy vegan adults with ages between 18 and 65 years and having the reported dietary regimen for at least 1 year, free from any chronic condition such as metabolic, digestive, renal, haematological, endocrine or oncological diseases and presenting no food intolerances or eating disorders. Receives: Other: Blood and urine collection, anthropometric analysis and answering to questionnaires |
What is being measured
The primary outcome is the main question the study is designed to answer.
Diet Quality Index for each regimen
Diet quality will be assessed through a Diet Quality Index (DQI) created by VeggieNutri's workteam. DQI is a tool that quantifies the quality of an individual's intake, scoring their food intake, assessed buy a Food Frequency Questionnaire (FFQ). Each question regarding their food intake will be scored from 0 to 10 points, depending on how close they are to complying with guidelines and recommendations (the closer to complying, the highest the scoring and the farthest, the lower the scoring).
Measured: 7 months
Nutritional inadequacy prevalences
Nutritional inadequacy prevalences will be calculated based on DQI scores and also on reference values for micronutrients in blood or urine.
Measured: 11 months
Secondary outcomes (5)
Levels of vitamins B12, B6, B9 and D, homocysteine, iron, selenium, calcium, zinc and magnesium
Measured in blood samples.
Measured: 6 months
Waist circunference and percentage of body fat
Assessed through anthropometric analysis including bioelectrical impedance, on the recruitment day.
Measured: 6 months
Fasting glycaemia and HOMA-IR
Quantification of fasting blood glucose and insulin.
Measured: 6 months
Blood LDL, HDL and total cholesterol and triglycerides
Assessed through the analysis of blood samples.
Measured: 6 months
Urinary iodine concentration
Assessed through the analysis of urine samples.
Measured: 6 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Jun 2022
- Study start1 Jul 2022
- Primary completionDec 2023 (estimated)
- Study completionJun 2024 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Diet, VegetarianStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Other
- Time perspective
- Other
- Enrolment
- 400 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Universidade do Porto
- Sponsor type
- University, hospital or other
- Collaborators
- Centro Hospitalar De São João, E.P.E., Centro de Investigação em Tecnologias e Serviços de Saúde, Rede de Investigação em Saúde
- Responsible party
- Sponsor
- Investigators
- Elisa Keating, PhD, Principal investigator, Universidade do Porto
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05408962
- Sponsor's protocol ID
- VeggieNutri_2022
- Acronym
- VeggieNutri
- Status last verified
- Oct 2023
- First submitted
- 3 Jun 2022
- Last updated
- 19 Oct 2023
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 19 Oct 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- VeggieNutri - Nutritional and Metabolic Status of Vegetarian and Omnivorous Portuguese Adults
- ClinicalTrials.gov ID
- NCT05408962
- Acronym / sponsor ID
- VeggieNutri / VeggieNutri_2022
- Conditions
- Diet, Vegetarian, Diet, Vegan, Nutritional Status, Metabolic Profile
- Keywords
- Vegetarian, Vegan, Diet quality, Metabolic profile, Nutritional status, Metabolic outcomes, Sustainable diets, Sustainability
- Study type
- Observational
- Recruitment status
- Unknown status
- Enrolment
- 400 participants (estimated)
- Lead sponsor
- Universidade do PortoUniversity, hospital or other
- Collaborators
- Centro Hospitalar De São João, E.P.E., Centro de Investigação em Tecnologias e Serviços de Saúde, Rede de Investigação em Saúde
- Study start
- 1 Jul 2022 (actual)
- Primary completion
- Dec 2023 (estimated)
- Study completion
- Jun 2024 (estimated)
- First posted
- 7 Jun 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Vegetarian diets have low environmental footprints and are potential solutions to address climate change and the 2030 Agenda on the Sustainable Development Goals. Currently, there is no information regarding the nutritional quality of vegetarian diets in Portugal. As the trend for vegetarianism increases in the country, the aim of this study is to examine and compare nutritional and metabolic outcomes among vegetarian and non-vegetarian populations. We aim to implement a cross-sectional study that includes a total of 400 (distributed among the three diferent groups of omnivorous, lacto-ovovegatarians and vegans) healthy Portuguese adults aged 18-64 years. Blood and urine samples will be collected. Participants will be assessed for blood pressure, anthropometric parameters, micronutrient status, blood lipids, glicaemia and insuline resistance and will complete a validated food frequency questionnaire as well as a sociodemographic and lifestyle questionnaire. Dietary and nutrient analysis will be conducted to assess diet quality and nutritional inadequacies. The current proposal provides an unique opportunity to characterize and compare different population groups clustered by dietary behaviour and provide evidence that help achieve healthy and sustainable diets in Portugal.
Detailed description
Plant-based diets have been proven to be sustainable and to have low environmental impact, highlighting the importance of promoting a dietary shift towards plant-based diets, with reduction in the consumption of animal food sources. In particular, vegetarian diets can refer to vegan (VEG) diets that completely exclude all animal derived foods or to lacto-ovo vegetarians (LOV) which include eggs and milk products and have low environmental footprint compared with omnivorous dietary patterns. Vegetarian diets are gaining popularity around the world. The reasons to follow a vegetarian diet are diverse and reported to be related to religion, animal welfare, sustainability and environmental reasons, as well as health related concerns. Literature has shown several health benefits of these diets. Regarding the efficiency of vegetarianism in promoting weight loss, studies in which a lacto-ovo vegetarian or vegan diet are administered to participants show that participants with previous plant based-diets that do not fully adhere to the prescribed weight loss diet loose more weight when compared to non-vegetarians. Moreover, vegan diets have been shown to be more effective in improving body composition and insulin resistance, when compared to an omnivorous diet. Despite the above referred evidence regarding beneficial effects on weight loss, some studies find no statistical differences on weight loss promoted by vegetarians, omnivorous or Mediterranean diets. Plant-based diets were also found to improve glycaemic control and insulin sensitivity. In fact, there is evidence on vegetarians having lower fasting insulin level and higher insulin sensitivity compared with matched omnivores. Moreover, these diets are considered to have a low inflammatory load to the point of being considered as an approach to lower inflammatory markers in patients with coronary artery disease. Nevertheless, since vegetarian diets are restrictive, they may give rise to nutritionally unbalanced regimens, particularly when adopted without nutritional counselling. In fact, several studies link vegetarian diets to poor nutritional status, including micronutrient deficiency. In this context, the great rise of vegetarian habits among Portuguese population, which are reported to have quadruplicated in the last 10 years, poses important health concerns. Nevertheless, data on the nutritional status characteristics and metabolic profile of such consumers and of the nutritional adequacy of their diet are scarce, particularly comparing with people with omnivorous dietary regimens.
So, it is crucial to assess the quality of vegetarian diets in the country, identifying clear health benefits and risks from a nutritional perspective. Considering the importance of promoting environmentally sustainable diets at national level and the lack of data regarding the diet quality of vegetarian diets in the country, we propose the implementation of the first cross-sectional study in the country to investigate and compare nutritional and health parameters among vegetarian and omnivorous populations. The current proposal provides an unique opportunity to characterize and compare different population groups clustered by dietary behaviour and identify potential risks and gaps to attain health and environmental goals, such as contributing to the Portugal commitments to achieve the 2030 Agenda on the Sustainable Development Goals.
Study design
- Observational model
- Other
- Time perspective
- Other
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| OMNI - omnivorous | – | Other: Blood and urine collection, anthropometric analysis and answering to questionnairesHealthy omnivorous adults with ages between 18 and 65 years and having the reported dietary regimen for at least 1 year, free from any chronic condition such as metabolic, digestive, renal, haematological, endocrine or oncological diseases and presenting no food intolerances or eating disorders. |
| LOV - lacto-ovovegetarians | – | Other: Blood and urine collection, anthropometric analysis and answering to questionnairesHealthy lacto-ovovegetarians adults with ages between 18 and 65 years and having the reported dietary regimen for at least 1 year, free from any chronic condition such as metabolic, digestive, renal, haematological, endocrine or oncological diseases and presenting no food intolerances or eating disorders. |
| VEG - vegan | – | Other: Blood and urine collection, anthropometric analysis and answering to questionnairesHealthy vegan adults with ages between 18 and 65 years and having the reported dietary regimen for at least 1 year, free from any chronic condition such as metabolic, digestive, renal, haematological, endocrine or oncological diseases and presenting no food intolerances or eating disorders. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Participants will be recruited from general population. During advertisement, people will be invited to express their interest by filling in an online form which will include information about participation eligibility (eligibility criteria explained bellow). On recruitment day eligible participants will be asked to visit the recruitment center in fasting for blood and urine collection. In addition they will sign an informed consent, answer the lifestyle questionnaire and the Food Frequency Questionnaire and will be submitted to an anthropometric analysis and evaluation of blood preassure and heart rate.
Key inclusion criteria (3 listed)
- being a healthy adult
- being aged between 18 and 65 years
- having the reported dietary regimen for at least 1 year
Key exclusion criteria (8 listed)
- being free from metabolic disorders
- being free from digestive disorders
- being free from renal disorders
- being free from haematological disorders
- being free from endocrine disorders
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Blood and urine collection, anthropometric analysis and answering to questionnairesDuring the visit to the recruitment center, participants will sign an informed consent. They will have to be in fasting condition for blood and urine collection. In addition they will answer the lifestyle questionnaire and the Food Frequency Questionnaire and will be submitted to an anthropometric analysis and evaluation of blood preassure and heart rate. | Other | LOV - lacto-ovovegetarians, OMNI - omnivorous, VEG - vegan |
Primary outcome
Diet Quality Index for each regimen
Time frame: 7 months
Diet quality will be assessed through a Diet Quality Index (DQI) created by VeggieNutri's workteam. DQI is a tool that quantifies the quality of an individual's intake, scoring their food intake, assessed buy a Food Frequency Questionnaire (FFQ). Each question regarding their food intake will be scored from 0 to 10 points, depending on how close they are to complying with guidelines and recommendations (the closer to complying, the highest the scoring and the farthest, the lower the scoring).
Nutritional inadequacy prevalences
Time frame: 11 months
Nutritional inadequacy prevalences will be calculated based on DQI scores and also on reference values for micronutrients in blood or urine.
5 secondary outcomes
Levels of vitamins B12, B6, B9 and D, homocysteine, iron, selenium, calcium, zinc and magnesium
Time frame: 6 months
Waist circunference and percentage of body fat
Time frame: 6 months
Fasting glycaemia and HOMA-IR
Time frame: 6 months
Blood LDL, HDL and total cholesterol and triglycerides
Time frame: 6 months
Urinary iodine concentration
Time frame: 6 months
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 Oct 2023.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Elisa Keating, PhD principal investigator
Universidade do Porto
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Diet, Vegetarian and Diet, Vegan, run by Universidade do Porto at 1 site in Portugal.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: status not confirmed, as of the sponsor's last update on 19 Oct 2023. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Portugal. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
Contact Elisa Keating, PhD ((+351) 225513624, keating@med.up.pt), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Diet Quality Index for each regimen (time frame: 7 months). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 19 Oct 2023.