Writing data – Health

Write health and fitness data to Apple HealthKit on iOS and Health Connect on Android, with the write method that matches each data type.

The Health class provides a write method per kind of data. All write methods require WRITE permission for the types you write; see Permissions. For the full API, see the API reference on pub.dev.

Write methods

Method	Data types	Use case	Guide
`writeHealthData`	Most numeric types	General health metrics (weight, height, heart rate, blood glucose and so on)	Numeric data
`writeWorkoutData`	`WORKOUT`	Exercise sessions with activity types	Workouts
`writeBloodPressure`	`BLOOD_PRESSURE_*`	Systolic and diastolic readings	Blood pressure and oxygen
`writeBloodOxygen`	`BLOOD_OXYGEN`	Blood oxygen saturation	Blood pressure and oxygen
`writeMeal`	`NUTRITION`	Meals with macronutrients and micronutrients	Nutrition
`writeMenstruationFlow`	`MENSTRUATION_FLOW`	Menstrual cycle tracking	Specialized types
`writeAudiogram`	`AUDIOGRAM`	Hearing test results	Specialized types
`writeInsulinDelivery`	`INSULIN_DELIVERY`	Insulin doses	Specialized types

To remove data, see Deleting data.

Write flow

Request WRITE permission, then write the value. Each write method returns true on success.

// 1. Request write permissions
final types = [HealthDataType.WEIGHT];
final permissions = [HealthDataAccess.WRITE];

await health.requestAuthorization(types, permissions: permissions);

// 2. Write the data
final success = await health.writeHealthData(
  value: 70.5,
  type: HealthDataType.WEIGHT,
  startTime: DateTime.now(),
);

if (success) {
  print('Weight saved successfully');
} else {
  print('Failed to save weight');
}

Request write permission

Always request WRITE permission before you write. Pass one HealthDataAccess value per type:

final writeTypes = [
  HealthDataType.WEIGHT,
  HealthDataType.HEIGHT,
  HealthDataType.STEPS,
];

final granted = await health.requestAuthorization(
  writeTypes,
  permissions: List.filled(writeTypes.length, HealthDataAccess.WRITE),
);

Constraints and errors

The start time must be less than or equal to the end time. Otherwise, the plugin throws an ArgumentError.
WRITE is not allowed for ECG and event types: ELECTROCARDIOGRAM, HIGH_HEART_RATE_EVENT, LOW_HEART_RATE_EVENT, IRREGULAR_HEART_RATE_EVENT, WALKING_HEART_RATE and ATRIAL_FIBRILLATION_BURDEN. Requesting WRITE permission for these types throws.
On iOS, recordingMethod must be manual or automatic.
If the data type is not supported on the current platform, the plugin throws a HealthException.
Workout activity types are platform-specific. The plugin validates the activity type and throws if it is not supported on the current platform.
For sleep and headache types, the plugin ignores the value you pass and sets the correct categorical value automatically, based on the type.

Data validation

The plugin performs basic validation. The platform may also reject values:

// ✅ Valid
await health.writeHealthData(
  value: 70.5,
  type: HealthDataType.WEIGHT,
  startTime: DateTime.now(),
);

// ❌ Invalid - negative weight
await health.writeHealthData(
  value: -70.5,
  type: HealthDataType.WEIGHT,
  startTime: DateTime.now(),
); // May fail or be rejected by platform

// ❌ Invalid - future timestamp
await health.writeHealthData(
  value: 70.5,
  type: HealthDataType.WEIGHT,
  startTime: DateTime.now().add(Duration(days: 1)),
); // May fail or be rejected by platform

Common patterns

Set the timestamp

// Current time (most common)
await health.writeHealthData(
  value: 72,
  type: HealthDataType.HEART_RATE,
  startTime: DateTime.now(),
);

// Specific past time
await health.writeHealthData(
  value: 98.6,
  type: HealthDataType.BODY_TEMPERATURE,
  startTime: DateTime(2024, 1, 15, 8, 30),
);

Handle a failed write

A write returns false when it fails, for example because permission is missing:

try {
  final success = await health.writeHealthData(
    value: 120,
    type: HealthDataType.BLOOD_GLUCOSE,
    startTime: DateTime.now(),
  );
  
  if (success) {
    print('Data saved');
  } else {
    print('Write failed - check permissions');
  }
} catch (e) {
  print('Error: $e');
}

Write several values

Future<void> saveMultipleReadings() async {
  final readings = [
    {'type': HealthDataType.WEIGHT, 'value': 70.5},
    {'type': HealthDataType.HEIGHT, 'value': 175.0},
    {'type': HealthDataType.BODY_FAT_PERCENTAGE, 'value': 18.5},
  ];
  
  for (var reading in readings) {
    await health.writeHealthData(
      value: reading['value'] as double,
      type: reading['type'] as HealthDataType,
      startTime: DateTime.now(),
    );
  }
}

Quick reference

One call per write method. For details, follow the guide links in the Write methods table.

Generic write

Use writeHealthData for most numeric types. Units default per type, but you can provide one on iOS.

final ok = await health.writeHealthData(
  value: 70,
  type: HealthDataType.HEART_RATE,
  startTime: start,
  endTime: end,
  recordingMethod: RecordingMethod.manual, // iOS: only manual/automatic
);

Workout

final ok = await health.writeWorkoutData(
  activityType: HealthWorkoutActivityType.RUNNING,
  start: start,
  end: end,
  totalEnergyBurned: 400, // kcal (iOS)
  totalDistance: 3000,    // meter (iOS)
  title: 'Evening run',    // used on Android Health Connect
  recordingMethod: RecordingMethod.automatic,
);

Blood pressure

await health.writeBloodPressure(
  systolic: 120,
  diastolic: 80,
  startTime: time,
  clientRecordId: 'my-id-1', // optional
  clientRecordVersion: 1.0,  // optional
);

Blood oxygen

await health.writeBloodOxygen(
  saturation: 98.0,
  startTime: time,
  recordingMethod: RecordingMethod.automatic,
);

Meal

writeMeal supports many micronutrients; pass the values you have.

await health.writeMeal(
  mealType: MealType.DINNER,
  startTime: start,
  endTime: end,
  name: 'Pasta',
  caloriesConsumed: 850,
  protein: 32,
  fatTotal: 28,
  carbohydrates: 110,
  // ...many micronutrients supported; pass what you have
);

Menstruation flow

await health.writeMenstruationFlow(
  flow: MenstrualFlow.medium,
  isStartOfCycle: true,
  startTime: start,
  endTime: end,
);

Audiogram (iOS only)

await health.writeAudiogram(
  frequencies: [125, 500, 1000, 2000, 4000, 8000],
  leftEarSensitivities:  [49, 54, 89, 52, 77, 35],
  rightEarSensitivities: [76, 66, 90, 22, 85, 45],
  startTime: start,
  endTime: end,
  metadata: {
    'HKExternalUUID': 'your-id',
    'HKDeviceName': 'device name',
  },
);

Insulin delivery (iOS only)

await health.writeInsulinDelivery(
  5.0,
  InsulinDeliveryReason.BOLUS,
  start,
  end,
);

Platform differences

Android

iOS

Requires the Health Connect SDK to be available.
Write operations may return false if Health Connect is not installed.
Data syncs across connected apps.
Some specialized types may have limited support.

Your app cannot read data it wrote without READ permission.
Write operations return true on success.
Data appears immediately in the Apple Health app.
All value types are supported.