Clinical Trial Details
— Status: Recruiting
Administrative data
| NCT number |
NCT05408962 |
| Other study ID # |
VeggieNutri_2022 |
| Secondary ID |
|
| Status |
Recruiting |
| Phase |
|
| First received |
|
| Last updated |
|
| Start date |
July 1, 2022 |
| Est. completion date |
June 2024 |
Study information
| Verified date |
October 2023 |
| Source |
Universidade do Porto |
| Contact |
Elisa Keating, PhD |
| Phone |
(+351) 225513624 |
| Email |
keating[@]med.up.pt |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Observational
|
Clinical 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. 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.
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.
