Problem: BMI calculations can be confusing for people unfamiliar with the formula and its interpretation.

Solution: BMI Health Explorer is an interactive R Shiny application that calculates BMI and displays a corresponding weight-category interpretation.

• Simple interface
• Instant calculation
• Easy-to-understand results

The application takes two inputs:

• Weight in kilograms (kg)
• Height in centimetres (cm)

BMI formula:

\[ BMI = \frac{\text{Weight (kg)}}{\text{Height (m)}^2} \]

The app converts height into metres, calculates BMI, and displays the result and its category.

Technology: R, Shiny, and interactive user inputs.

Open the live application

This R expression calculates BMI and classifies the result.

weight <- 65
height <- 1.65

bmi <- weight / height^2
round(bmi, 2)

## [1] 23.88

if (bmi < 18.5) {
  category <- "Underweight"
} else if (bmi < 25) {
  category <- "Healthy weight"
} else if (bmi < 30) {
  category <- "Overweight"
} else {
  category <- "Obesity"
}

category

## [1] "Healthy weight"

For a weight of 65 kg and height of 1.65 m, the BMI is approximately 23.88, classified as Healthy weight using these conventional adult BMI categories.

Key takeaway: BMI Health Explorer demonstrates how R and Shiny can turn a simple calculation into an interactive health application.

Limitations: - BMI is a screening measure, not a complete assessment of health. - It does not account for factors such as muscle mass or body-fat distribution. - Adult BMI categories may not be appropriate for every population.

Project links:

• Live Shiny application
• GitHub repository