CDC Obesity Analysis – Behavioral Risk Factor Surveillance System (BRFSS)

Author: Zixuan Hao
Date: November 2025

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🧭 Overview

This project conducts an exploratory analysis of data from the CDC’s Behavioral Risk Factor Surveillance System (BRFSS), focusing on obesity prevalence by race/ethnicity in Georgia (2011).

The workflow demonstrates reproducible data science principles:

• Organized file structure
• Reproducible scripts using here
• Automation with a Makefile
• Modular analysis (analysis scripts, saved outputs, and report rendering)

Contents of the Report

• Data Import & Cleaning
• Descriptive Statistics
• Obesity Prevalence by Race/Ethnicity
• Visualization of Key Findings
• Summary & Interpretation

Report Description — FinalProject_R_ZixuanHao.html

• FinalProject_R_ZixuanHao.html is located in the /final_project_R folder.
• use make install to install the project environment
• use make all to run the full analysis pipeline
• use make clean to clean generated files

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code/code_analysis.R

• Reads the BRFSS dataset (data/brfss_obesity.csv)
• Cleans and recodes variables
• Creates summary statistics and graphics
• Saves outputs to output/table1.rds and output/figure1.rds

code/render_report.R

• Uses rmarkdown::render() to knit the main R Markdown file
• Produces the final HTML report
• Saves output to output/FinalProject_R_ZixuanHao.html

📁 Project Structure

final_project_R

• code/

  • code_analysis.R — Processes raw BRFSS data and generates cleaned outputs (tables + figures)
  • render_report.R — Knits the final R Markdown report using rmarkdown::render()

• data/

  • brfss_obesity.csv — Raw input dataset used in the analysis

• output/

  • table1.rds — Saved summary table for use in the final report
  • figure1.rds — Saved ggplot figure (obesity by race/ethnicity)
  • May also contain the rendered HTML report, depending on the workflow

• renv/

  • Folder automatically created by renv to store isolated package libraries
  • Contains:
    • activate.R — Bootstraps renv when opening the project
    • settings.json — Project-level renv configuration
    • library/ — Local package installations (usually excluded from GitHub)

• renv.lock

  • Lockfile recording the exact R package versions used in this project for full reproducibility

• Makefile

  • Automates the workflow: environment restoration (make install), running analysis scripts, cleaning outputs, and rendering the final report

• final_project_R.Rproj

  • RStudio project file that defines the working environment

• FinalProject_R_ZixuanHao.Rmd

  • Main R Markdown file that imports saved outputs and generates the final HTML report

• FinalProject_R_ZixuanHao.html

  • Rendered HTML report created from the R Markdown file

• README.md

  • Documentation describing the purpose, structure, and reproducibility instructions of the project

Reproducibility With renv

This project uses the renv package to ensure full reproducibility across systems.

Restore the exact package environment used in this project:

make install

This runs:

renv::restore()