private fun updateFeedback() {
        val now = DateTime.now()
        val dayOfWeek = now.dayOfWeek
        val isMonday = dayOfWeek == 1

        val faceIcon: Int
        val message: String
        if (isMonday) {
            val nowWeekdayIndex = dayOfWeek - 1
            val last4WeekCalories = (1..4).sumByDouble { model.days[model.days.size - ((model.weekDays * (it + 1)) - nowWeekdayIndex)].intakeCalories.toDouble() }.toFloat()
            val average4WeeksCalories = last4WeekCalories / 4
            faceIcon = R.drawable.feedback_logging_info
            message = repository.getString(R.string.logging_cal_and_activities_feedback_info, Math.round(average4WeeksCalories))
        } else {
            val acceptedKcalOffside = 50f
            val thisWeekStart = DateUtils.getWeekStart(now)
            val thisWeekEnd = DateUtils.getWeekEnd(thisWeekStart).withMillisOfDay(0).plusDays(1)

            val daysLoggedThisWeek = model.days
                    .filter { it.dateTime.isAfter(thisWeekStart.minus(1)) && it.dateTime.isBefore(thisWeekStart.plusWeeks(1)) }
                    .filter { it.intakeCalories > 0f }
                    .count()

            val daysInRecommendedRange = model.days
                    .filter { it.dateTime.isAfter(thisWeekStart.minus(1)) && it.dateTime.isBefore(thisWeekEnd) }
                    .filter {
                        val intake = it.intakeCalories
                        val min = it.recommendCalories - acceptedKcalOffside
                        val max = it.recommendCalories + acceptedKcalOffside
                        intake in min..max
                    }
                    .count()

            val value = daysInRecommendedRange.toFloat() / now.dayOfWeek.toFloat()
            if (value >= 0.5f) {
                faceIcon = R.drawable.feedback_logging_positive
                message = repository.getString(R.string.logging_cal_and_activities_feedback_positive, daysInRecommendedRange, daysLoggedThisWeek)
            } else {
                faceIcon = R.drawable.feedback_logging_negative
                message = repository.getString(R.string.logging_cal_and_activities_feedback_negative, daysInRecommendedRange, daysLoggedThisWeek)
            }
        }