Dietary Quality and Nutritional Adequacy Among Vegetarians Attending the European Institute of Oncology (VEGETARIANS)

Survey on Dietary Quality and Nutritional Adequacy Among Vegetarians Attending the European Institute of Oncology

Despite their health benefits, vegetarian dietary patterns can lead to malnutrition and micronutrient deficiencies if improperly managed, especially in oncological settings. This survey assesses dietary quality and adequacy in 150 women (18-64 years), further examining how a threemonth nutritional counseling intervention influences body composition, physical activity, and quality of life.

Study Overview

• Status: Recruiting
• Conditions: Quality of Life; Nutritional Deficiencies
• Intervention / Treatment: Other: personalized nutritional counseling

Detailed Description

150 vegan, vegetarian, semi-vegetarian women (18-64 years) will be recruited among patients attending the European Institute of Oncology for prevention visits or oncological follow-up. The study will include a baseline visit and a 3-month follow-up visit, with an interim telephone contact.

At baseline, nutritional adequacy and diet quality will be assessed, followed by a personalized nutritional counselling aimed at improving dietary variety, ensuring adequate nutrient intake, and promoting an active lifestyle. The intervention will be based on a vegetarian adaptation of the Healthy Eating Plate and aligned with national and international guidelines (CREA,2019; WCRF, 2018).

During study visits, anthropometric measurements (height, weight, waist and hip circumferences), body composition (BIVA), and blood samples will be collected. Dietary intake will be evaluated via a 3-day food records. Validated questionnaires will be administered to assess physical activity (IPAQ-SF), adherence to the Mediterranean diet (QueMD), and quality of life (VEGQOL). Additionally, vegetarian diet quality and lifestyle will be evaluated using the Vegetarian Lifestyle Index.

Nutritional adequacy will be determined by comparing dietary intake and blood biomarkers with Italian Dietary Reference Values (DRVs; SINU 2024).

• Study Type: Interventional
• Enrollment (Estimated): 150
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Patrizia Gnagnarella, PhD; Phone Number: +39 0257489823; Email: patrizia.gnagnarella@ieo.it

Study Locations

• Italy
  • Milan, Italy, 20141
    • Recruiting
    • European Institute of Oncology, Milan, Recruiting
    • Contact: Patrizia Gnagnarella; Phone Number: +39 0257489823; Email: patrizia.gnagnarella@ieo.it
    • Contact: Davide Serrano; Email: davide.serrano@ieo.it

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• pre or post-menopausal women, aged between 18 and 64;
• healthy participants or high-risk cancer patients or patients with previous diagnosis of neoplasia
• self-identifying as vegan (defined as excluding all animal products), or vegetarian (defined as excluding all animal products besides eggs and/or dairy) or semi-vegetarian (defined as excluding no animal products but limiting meat to < 1× per week);
• ability to understand and the willingness to sign a written informed consent document;

Exclusion Criteria:

• any condition which, in the opinion of the investigator, may impede testing of the study hypothesis or make it unsafe to engage in the study (e.g., ulcerative colitis, Crohn's disease etc.);
• any diagnosis of invasive neoplasia, within the previous 1 years, except non-melanoma skin cancer;
• currently receiving chemotherapy, radiation, or immunotherapy as cancer treatment;
• patients dependent on enteral or parental nutrition;
• pregnancy or lactation;

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: vegetarian study population; The study population comprises 150 women (18-64 years) adhering to plant-based diets (vegan, vegetarian, or semi-vegetarian), including both healthy individuals and those with a history or high risk of cancer recruited at the European Institute of Oncology (Milan, IT)	Other: personalized nutritional counseling; Participants will receive personalized nutritional counseling by registered dietitians based on blood tests and 3-day food records, focusing on improving diet variety and optimizing intake of critical nutrients. Additionally, lifestyle advice will be provided to increase physical activity and reduce sedentary behavior.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Survey on nutritional adequacy of participants' diet at baseline	Nutritional adequacy evaluated through blood biomarkers and dietary intake, assessed via 3-day food records. Nutrient data will be referenced against the Italian Dietary Reference Values (DRVs). Nutritional adequacy will be quantified by calculating the Nutrient Adequacy Ratio (NAR) and the Mean Adequacy Ratio (MAR). The NAR represents the ratio of an individual's nutrient intake to the corresponding Italian DRV for their age group, while the MAR is the average of all calculated NARs. Both indices will be expressed on a scale from 0 to 1, where 0 indicates that nutrient requirements are not met and 1 indicates that they are fully met.	Baseline
Survey on dietary and lifestyle quality of participants at baseline	A modified version of the vegetarian Lifestyle index is adapted to Italian guidelines and national recommendations. The score comprises 11 dietary and 3 lifestyle components and ranges from 0 to 14, with higher score indicating greater adherence.	Baseline

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Nutrient Adequacy Ratio (NAR)	change in NAR calculated by dividing participant's intake of a given nutrient by the Italian DRVs for the corresponding age category	3-month
Mean Adequacy Ratio (MAR)	change in MAR calculated by averaging all NARs together	3-month
Vegetarian life style index (VLI)	change in vegetarian Lifestyle score ranging from 0 to 14, with higher score indicating greater adherence.	3-month
Blood analysis- glucose	change in concentration of glucose (mg/dl)	3-month
Blood analysis- insulin	change in concentration of insulin (mUI/L)	3-month
Blood analysis- total cholesterol	change in concentration of total cholesterol (mg/dl)	3-month
Blood analysis-LDL cholesterol	change in concentration of LDL cholesterol (mg/dl)	3-month
Blood analysis-HDL cholesterol	change in concentration HDL cholesterol (mg/dl)	3-month
Blood analysis-triglycerides (mg/dl)	change in concentration of triglycerides (mg/dl)	3-month
Blood analysis- vitamins-B6	change in concentration of B6(mcg/L)	3-month
Blood analysis- vitamins-B12	change in concentration of B12 (ng/L)	3-month
Blood analysis- vitamins-folate	change in concentration of folate (mcg/L)	3-month
Blood analysis- vitamins-Vitamin D	change in concentration of Vitamin D (mcg/L)	3-month
Blood analysis- iron status	change in concentration of iron (mcg/dl)	3-month
Blood analysis- ferritin status	change in concentration of ferritin (mcg/L)	3-month
Blood analysis- Calcium	change in concentration of calcium (mg/dl)	3-month
Blood analysis- total protein	change in concentration of total protein (g/dl)	3-month
Anthropometric measurements - Body weight	change in Body weight (kg)	3-month
Anthropometric measurements - circumferences	change in waist and hip circumferences (cm)	3-month
Anthropometric measurements - Body composition	change in fat mass and fat free mass (kg)	3-month
Physical activity	change in metabolic equivalents of tasks (METs), measured by the short version of the International Physical Activity Questionnaire (IPAQ-sf)	3-month
Quality of life (VEGQOL)	change in VEGQOL score ranging from 0-100 scale, with higer score indicating better QoL.	3-month
Adherence to the Mediterranean diet	change in Mediterranean diet adherence score ranging from 0 to 9, with higer scores indicating better adherence	3-month

Collaborators and Investigators

• Sponsor: European Institute of Oncology
• Investigators: Principal Investigator: Patrizia Gnagnarella, PhD, European Institute of Oncology

Study record dates

Study Major Dates

• Study Start (Actual): March 26, 2026
• Primary Completion (Estimated): January 26, 2028
• Study Completion (Estimated): January 26, 2028

Study Registration Dates

• First Submitted: March 25, 2026
• First Submitted That Met QC Criteria: June 9, 2026
• First Posted (Actual): June 10, 2026

Study Record Updates

• Last Update Posted (Actual): June 10, 2026
• Last Update Submitted That Met QC Criteria: June 9, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: vegetarian; vegan; semivegetarian diet
• Additional Relevant MeSH Terms: Nutrition Disorders; Nutritional and Metabolic Diseases; Malnutrition
• Other Study ID Numbers: UID 4909; L2-476 (Other Identifier: Comitato Etico Territoriale Lombardia 2)

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