Calorie Calculator

package main

import (
  "fmt"
  "math"
  "bufio"
  "os"
)

func main() {
    var gender string
    fmt.Scanln(&gender)

    var weight, height, basalMetabolicRate, coefficientActivity float64
    fmt.Scanln(&weight)
    fmt.Scanln(&height)

    var age int
    fmt.Scanln(&age)

    scanner := bufio.NewScanner(os.Stdin)
    scanner.Scan()
    physicalActivity := scanner.Text()

    if gender == "m" {
        basalMetabolicRate = 66 + weight * 13.7 + height * 500 - 6.8 * float64(age)
    } else {
        basalMetabolicRate = 655 + weight * 9.6 + height * 180 - 4.7 * float64(age)
    }

    switch physicalActivity {
        case "sedentary":
            coefficientActivity = 1.2
        case "lightly active":
            coefficientActivity = 1.375
        case "moderately active":
            coefficientActivity = 1.55
        default:
            coefficientActivity = 1.725
    }

    calories := int(math.Ceil(basalMetabolicRate * coefficientActivity))
    fmt.Printf("To maintain your current weight you will need %d calories per day.\n", calories)
}