LeanBodyMassRecord: Health Connect lean body mass data

What Google says LeanBodyMassRecord is

Captures the user's lean body mass. Each record represents a single instantaneous measurement.

Quoted from Google’s LeanBodyMassRecord Jetpack reference, last updated 2026-06-24, read 2026-10-03.

Class

androidx.health.connect.client.records.LeanBodyMassRecord

Google's category

Body Measurement

Record type

Instantaneous

Unit class

androidx.health.connect.client.units.Mass

Mandatory fields

massmetadatatime

Added in (Jetpack)

1.1.0

Permissions

The exact strings Google’s data-types table declares for LeanBodyMassRecord. Google’s page: “Before requesting any permissions, your app must declare them in the manifest.”

<uses-permission android:name="android.permission.health.READ_LEAN_BODY_MASS" />
<uses-permission android:name="android.permission.health.WRITE_LEAN_BODY_MASS" />

import androidx.health.connect.client.permission.HealthPermission
import androidx.health.connect.client.records.LeanBodyMassRecord

val permissions = setOf(
    HealthPermission.getReadPermission(LeanBodyMassRecord::class),
    HealthPermission.getWritePermission(LeanBodyMassRecord::class),
)

The 4 fields of LeanBodyMassRecord

Types and descriptions as Google’s reference prints them. The range column quotes Google’s own range annotation or sentence; a dash means Google states none, which is not the same as no validation.

Read LeanBodyMassRecord in Kotlin

The shape of Google’s own read example, with LeanBodyMassRecord and its names filled in. Get the client with HealthConnectClient.getOrCreate(context) after checking getSdkStatus.

import androidx.health.connect.client.HealthConnectClient
import androidx.health.connect.client.records.LeanBodyMassRecord
import androidx.health.connect.client.request.ReadRecordsRequest
import androidx.health.connect.client.time.TimeRangeFilter
import java.time.Instant

suspend fun readLeanBodyMass(
    client: HealthConnectClient,
    startTime: Instant,
    endTime: Instant,
): List<LeanBodyMassRecord> {
    val response = client.readRecords(
        ReadRecordsRequest(
            LeanBodyMassRecord::class,
            timeRangeFilter = TimeRangeFilter.between(startTime, endTime),
        )
    )
    // One page of up to pageSize records (default 1000); follow
    // response.pageToken for the rest.
    return response.records
}

Setting up the client, the permission flow and Play Console declaration: integrating Health Connect step by step.

HealthKit counterpart

The metric on other platforms

This guide lists LeanBodyMassRecord beside the types on the other platforms this site covers whose own descriptions name the same metric, each quoted, with how each one is read.

• Body Composition API: Weight, Body Fat, and Lean Mass Data

Questions

What permission does LeanBodyMassRecord need?

Google's Health Connect data-types table (read 2026-10-03) declares android.permission.health.READ_LEAN_BODY_MASS for reading LeanBodyMassRecord and android.permission.health.WRITE_LEAN_BODY_MASS for writing it, and says apps must declare permissions in the manifest before requesting them.

Can you aggregate LeanBodyMassRecord with AggregateRequest?

Not directly. As read on 2026-10-03, Google's Jetpack reference defines no AggregateMetric constants on LeanBodyMassRecord, so there is no metric to put in an AggregateRequest. Read the records with readRecords and a ReadRecordsRequest, and compute any summary yourself.

What values does LeanBodyMassRecord.mass accept?

Google's reference types mass as Mass. Its description reads: "Mass in Mass unit. Required field. Valid range: 0-1000 kilograms."

Is LeanBodyMassRecord an interval, instantaneous or series record?

Google's data-types table lists LeanBodyMassRecord as Instantaneous, and defines that column as indicating "whether the data is recorded at an instant in time or over an interval". Its mandatory fields are mass, metadata and time.