Impact of plant-based and traditional diets on micronutrient status and metabolic health in urban adults: a comparative longitudinal study

Project Abstract

This longitudinal comparative study examines how plant-based versus traditional omnivorous diets influence micronutrient status and metabolic health in urban adults over 18 months, integrating dietary assessment, biochemical markers, and lifestyle factors. A stratified random sample of 600 adults aged 20–45 from three metropolitan areas was enrolled and classified into plant-based (n=300) and traditional diet (n=300) groups, with equal representation of gender, socioeconomic status, and baseline BMI. Data collection occurred at baseline, 6, 12, and 18 months, including 24-hour dietary recalls, food frequency questionnaires, and validated nutrient intake analyses to quantify macro- and micronutrient consumption, antioxidant load, and dietary patterns. Primary biochemical endpoints encompassed fasting plasma concentrations of iron, ferritin, vitamin B12, folate, vitamin D, calcium, zinc, and selenium, alongside inflammatory (CRP, IL-6) and oxidative stress markers (malondialdehyde, total antioxidant capacity). Secondary endpoints included lipid profile (total cholesterol, LDL, HDL, triglycerides), glycemic control (fasting glucose, HbA1c), insulin resistance (HOMA-IR), blood pressure, body composition (DXA-derived fat and lean mass), and resting metabolic rate. Physical activity was monitored via accelerometry, and microbiome composition was assessed in a subsample (n=120 per group) through 16S rRNA sequencing to explore diet-microbiota-nutrient interactions. Data analysis employed mixed-effects models to evaluate trajectories of micronutrient status and metabolic health, adjusting for age, sex, BMI, energy intake, physical activity, supplement use, and socioeconomic factors. Mediation analyses explored whether micronutrient adequacy mediated the relationship between diet type and metabolic outcomes, while moderation analyses identified whether baseline BMI or microbiome diversity influenced observed effects. Qualitative components included semi-structured interviews to capture adherence determinants, perceived barriers to nutrient adequacy, and cultural acceptability of plant-based options, providing context for quantitative findings. Anticipated results expect plant-based diets to deliver higher intake of fiber, polyphenols, and certain micronutrients (folate, iron bioavailability considerations notwithstanding), with potential improvements in lipid profiles and inflammatory status, but possible risks of deficiencies in vitamin B12, vitamin D, calcium, iron, and zinc if not properly planned. The traditional diet group may show greater absolute intake of animal-source nutrients, potentially resulting in higher saturated fat exposure but improved iron and vitamin B12 status, depending on dietary choices. The study aims to generate evidence-based dietary guidelines for urban populations to optimize micronutrient sufficiency and metabolic health across diverse dietary patterns, emphasizing nutrient-dense food selection, appropriate supplementation where indicated (e.g., B12, D, calcium), and culturally tailored interventions to enhance long-term adherence and health outcomes. Findings are expected to inform nutrition policy, clinical practice, and public health messaging on sustainable, health-promoting dietary patterns in rapidly urbanizing settings.

Project Overview

What This Project Is About

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A plain-language overview of how different eating styles might affect nutrients and health in adults living in cities, checked over time to see how changes develop.

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The Problem It Addresses

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Many people switch between plant-based and traditional diets, but we don’t fully know how these choices affect micronutrient levels and overall metabolism in urban settings. This project fills that gap by watching real people over a period to compare outcomes.

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Objectives of the Project

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1. Compare micronutrient status between plant-based and traditional diets in urban adults.
2. Track metabolic health indicators (blood sugar, lipids, blood pressure) over time.
3. Identify diet-related factors that influence nutrient adequacy and metabolism.
4. Provide practical guidance for improving nutrient intake on different diets.

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What You Will Do Step by Step

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1) Recruit adult participants from urban communities who follow plant-based or traditional diets. 2) Collect baseline data on diet, health measures, and blood samples for nutrient levels. 3) Follow participants for 12 months, with periodic check-ins and dietary logs. 4) Analyze changes in micronutrient status and metabolic markers using simple comparisons and tracking. 5) Interpret results to find practical recommendations for balanced nutrient intake.

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Expected Outcome

We expect to see differences in certain micronutrients and metabolic markers between diet groups, with insights on how to optimize diets for better health in urban settings. The study should yield clear, actionable guidance for individuals and nutrition professionals.