Overweight and obesity and associated cardiometabolic risk factors in adults Nutritional, Metabolic, Endocrine
Conditions
Interventions
This study will evaluate the health effects of adopting either a vegan or vegetarian diet compared with maintaining a habitual omnivorous diet over 52 weeks. The intervention, titled Plant Your Health
Sponsors
University of Leicester
Eligibility
Sex/Gender
All
Age
18 Years to 50 Years
Inclusion criteria
Inclusion criteria: 1. Adults aged 18–50 years 2. Men and women 3. Body mass index (BMI) =25 and <40 kg/m² (= 23 kg/m² for individuals from ethnic minority backgrounds) 4. Self-reported stable weight over the previous 6 months (<+/- 5% of bodyweight) 5. Currently follows an omnivorous diet, defined as consumption of meat on at least 5 days per week over the previous six months, with no four-week or longer period of vegetarian or vegan eating during that time 6. Currently consumes dairy products (for example, but not limited to, milk in hot beverages, cheese, yogurt, butter, cream, or other foods containing milk) on at least five days per week over the past six months, with no four-week or longer period of abstaining from dairy products 7. Willing and able to provide written informed consent to participate in the trial 8. Able to understand written and spoken English, as interpreters will not be used 9. Willing to be randomised to any study arm (omnivore, vegetarian, or vegan) and to comply with all study procedures for the 12-month duration
Exclusion criteria
Exclusion criteria: 1. Diagnosed with type 1 or type 2 diabetes 2. Any significant hepatic, renal, or gastrointestinal condition (e.g., inflammatory bowel disease, coeliac disease, chronic liver or kidney disease) or any other medical or lifestyle factor (e.g., severe food allergy, intolerance, or eating disorder) that, in the investigator’s opinion, would compromise safety, affect nutrient absorption, or prevent adherence to a vegan or vegetarian diet 3. Currently receiving active treatment for cancer or renal disease, has experienced a cardiovascular event within the past six months, or is living with a serious illness with a life expectancy of less than 1 year 4. Use of prescription or over-the-counter lipid-lowering agents (e.g., statins, fibrates, niacin, plant sterol/stanol products, or red yeast rice) or high-dose omega-3 fatty acid supplements (=2 g/day eicosapentaenoic acid + docosahexaenoic acid combined). Participants taking low-dose over-the-counter omega-3 (=1 g/day) are not excluded. 5. Pregnant, breastfeeding, or planning pregnancy during the study period 6. Use of antibiotics, probiotics, prebiotics, or other supplements/medications that may affect TMAO metabolism or gut microbiota within the past 8 weeks (e.g., L-carnitine, choline, or FMO3 inhibitors) 7. Severe psychiatric illness, substance misuse, or any other major clinical factor likely to impair consent, participation, or adherence 8. Current use of weight-loss medication (e.g., glucagon-like peptide-1 receptor agonists/ Glucose-dependent insulinotropic polypeptide agonists or similar agents) 9. Current or planned long-term systemic corticosteroid use (=4 weeks) 10. Current participation in another interventional study that could influence outcomes or conflict with this trial. 11. Familial hypercholesterolaemia, diagnosed or clinically suspected 12. History of metabolic surgery
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Low-density lipoprotein cholesterol (LDL-C) (mmol/L) measured using fasted venous blood samples at baseline, 26 weeks and 52 weeks (primary) | — |
Secondary
| Measure | Time frame |
|---|---|
| Blood pressure (systolic and diastolic) measured using automated sphygmomanometry at baseline, 26 weeks and 52 weeks;Lipid profile measured using fasted venous blood samples at baseline, 26 weeks and 52 weeks;10-year cardiovascular disease risk measured using QRISK risk prediction algorithm at baseline, 26 weeks and 52 weeks;Glycaemic control (fasting glucose, fasting insulin, HbA1c, 2-h glucose) measured using fasted venous blood samples and an oral glucose tolerance test at baseline, 26 weeks and 52 weeks;Inflammatory biomarkers (hsCRP and IL-6) measured using fasted venous blood samples at baseline, 26 weeks and 52 weeks;Liver function markers (ALT, AST, ALP and bilirubin) measured using fasted venous blood samples at baseline, 26 weeks and 52 weeks;Renal function markers (urea, creatinine and eGFR) measured using fasted venous blood samples at baseline, 26 weeks and 52 weeks;Haematological markers measured using full blood count (FBC) analysis from fasted venous blood samples at baseline, 26 weeks and 52 weeks;Nutritional biomarkers (B12, ferritin, folate, vitamin D and TMAO) measured using fasted venous blood samples at baseline, 26 weeks and 52 weeks;Anthropometry (body weight, height, BMI, waist circumference) measured using standard anthropometric assessments at baseline, 26 weeks and 52 weeks;Body composition (phase angle, fat mass, lean body mass and bone mineral density) measured using bioelectrical impedance analysis (BIA) and dual energy X-ray absorptiometry (DXA) at baseline, 26 weeks and 52 weeks and DXA at baseline and 52 weeks only;Physical function measured using the STS-60 test and handgrip dynamometry at baseline, 26 weeks and 52 weeks;Disability and functional status measured using the WHODAS 2.0 questionnaire at baseline, 26 weeks and 52 weeks;Physical activity and sedentary behaviour measured using wrist-worn accelerometery and the General Practice Physical Activity Questionnaire (GPPAQ) at baseline, 26 weeks and 52 weeks;Health-related quali | — |
Countries
England, United Kingdom
Contacts
Public ContactClaire Bordoli
Outcome results
None listed