diff --git a/android_app/app/src/main/java/com/health/openscale/core/OpenScale.java b/android_app/app/src/main/java/com/health/openscale/core/OpenScale.java
index 19326965..3d5950d1 100644
--- a/android_app/app/src/main/java/com/health/openscale/core/OpenScale.java
+++ b/android_app/app/src/main/java/com/health/openscale/core/OpenScale.java
@@ -47,7 +47,6 @@ import java.io.OutputStreamWriter;
 import java.text.ParseException;
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
-import java.util.Date;
 import java.util.List;
 import java.util.Map;
 import java.util.TreeMap;
@@ -80,7 +79,7 @@ public class OpenScale {
         alarmHandler = new AlarmHandler();
         btCom = null;
         fragmentList = new ArrayList<>();
-        appDB = Room.databaseBuilder(context, AppDatabase.class, "openScaleDatabase").build();
+        appDB = Room.databaseBuilder(context, AppDatabase.class, "openScaleDatabase").allowMainThreadQueries().build();
         measurementDAO = appDB.measurementDAO();
         userDAO = appDB.userDAO();
 
@@ -95,30 +94,24 @@ public class OpenScale {
         return instance;
     }
 
-    public void addScaleUser(String name, Date birthday, int body_height, int scale_unit, int gender, float initial_weight, float goal_weight, Date goal_date)
+    public void addScaleUser(final ScaleUser user)
     {
-        ScaleUser scaleUser = new ScaleUser();
-
-        scaleUser.setUserName(name);
-        scaleUser.setBirthday(birthday);
-        scaleUser.setBodyHeight(body_height);
-        scaleUser.setScaleUnit(scale_unit);
-        scaleUser.setGender(gender);
-        scaleUser.setConvertedInitialWeight(initial_weight);
-        scaleUser.setGoalWeight(goal_weight);
-        scaleUser.setGoalDate(goal_date);
-
-        scaleUserDB.insertEntry(scaleUser);
+        AsyncTask.execute(new Runnable() {
+            @Override
+            public void run() {
+                userDAO.insert(user);
+            }
+        });
     }
 
-    public ArrayList<ScaleUser> getScaleUserList()
+    public List<ScaleUser> getScaleUserList()
     {
-        return scaleUserDB.getScaleUserList();
+        return userDAO.getAll();
     }
 
     public ScaleUser getScaleUser(int userId)
     {
-        return scaleUserDB.getScaleUser(userId);
+        return userDAO.getById(userId);
     }
 
     public ScaleUser getSelectedScaleUser()
@@ -133,7 +126,7 @@ public class OpenScale {
                 return scaleUser;
             }
 
-            scaleUser = scaleUserDB.getScaleUser(selectedUserId);
+            scaleUser = userDAO.getById(selectedUserId);
         } catch (Exception e) {
             Toast.makeText(context, "Error: " + e.getMessage(), Toast.LENGTH_SHORT).show();
         }
@@ -143,27 +136,14 @@ public class OpenScale {
 
     public void deleteScaleUser(int id)
     {
-        scaleUserDB.deleteEntry(id);
+        userDAO.delete(userDAO.getById(id));
     }
 
-    public void updateScaleUser(int id, String name, Date birthday, int body_height, int scale_unit, int gender, float initial_weight, float goal_weight, Date goal_date)
+    public void updateScaleUser(ScaleUser user)
     {
-        ScaleUser scaleUser = new ScaleUser();
-
-        scaleUser.setId(id);
-        scaleUser.setUserName(name);
-        scaleUser.setBirthday(birthday);
-        scaleUser.setBodyHeight(body_height);
-        scaleUser.setScaleUnit(scale_unit);
-        scaleUser.setGender(gender);
-        scaleUser.setConvertedInitialWeight(initial_weight);
-        scaleUser.setGoalWeight(goal_weight);
-        scaleUser.setGoalDate(goal_date);
-
-        scaleUserDB.updateScaleUser(scaleUser);
+        userDAO.update(user);
     }
 
-
     public ArrayList<ScaleData> getScaleDataList() {
         return scaleDataList;
     }
@@ -243,7 +223,7 @@ public class OpenScale {
     }
 
     private int getSmartUserAssignment(float weight, float range) {
-        ArrayList<ScaleUser> scaleUser = getScaleUserList();
+        List<ScaleUser> scaleUser = getScaleUserList();
         Map<Float, Integer> inRangeWeights = new TreeMap<>();
 
         for (int i = 0; i < scaleUser.size(); i++) {
diff --git a/android_app/app/src/main/java/com/health/openscale/core/database/ScaleUserDAO.java b/android_app/app/src/main/java/com/health/openscale/core/database/ScaleUserDAO.java
index a5389d5d..393f8c19 100644
--- a/android_app/app/src/main/java/com/health/openscale/core/database/ScaleUserDAO.java
+++ b/android_app/app/src/main/java/com/health/openscale/core/database/ScaleUserDAO.java
@@ -20,6 +20,7 @@ import android.arch.persistence.room.Dao;
 import android.arch.persistence.room.Delete;
 import android.arch.persistence.room.Insert;
 import android.arch.persistence.room.Query;
+import android.arch.persistence.room.Update;
 
 import com.health.openscale.core.datatypes.ScaleUser;
 
@@ -30,6 +31,9 @@ public interface ScaleUserDAO {
     @Query("SELECT * FROM scaleuser")
     List<ScaleUser> getAll();
 
+    @Query("SELECT * FROM scaleuser WHERE id IS :id")
+    ScaleUser getById(int id);
+
     @Query("SELECT * FROM scaleuser WHERE id IS :id")
     ScaleUser loadById(int id);
 
@@ -39,6 +43,9 @@ public interface ScaleUserDAO {
     @Insert
     void insertAll(ScaleUser... users);
 
+    @Update
+    void update(ScaleUser user);
+
     @Delete
     void delete(ScaleUser user);
 }
diff --git a/android_app/app/src/main/java/com/health/openscale/gui/activities/UserSettingsActivity.java b/android_app/app/src/main/java/com/health/openscale/gui/activities/UserSettingsActivity.java
index 49ba9134..73afca1d 100644
--- a/android_app/app/src/main/java/com/health/openscale/gui/activities/UserSettingsActivity.java
+++ b/android_app/app/src/main/java/com/health/openscale/gui/activities/UserSettingsActivity.java
@@ -36,9 +36,9 @@ import com.health.openscale.core.OpenScale;
 import com.health.openscale.core.datatypes.ScaleUser;
 
 import java.text.DateFormat;
-import java.util.ArrayList;
 import java.util.Calendar;
 import java.util.Date;
+import java.util.List;
 
 public class UserSettingsActivity extends Activity {
 
@@ -231,7 +231,7 @@ public class UserSettingsActivity extends Activity {
                     openScale.clearScaleData(userId);
                     openScale.deleteScaleUser(userId);
 
-                    ArrayList<ScaleUser> scaleUser = openScale.getScaleUserList();
+                    List<ScaleUser> scaleUser = openScale.getScaleUserList();
 
                     int lastUserId = -1;
 
@@ -302,11 +302,23 @@ public class UserSettingsActivity extends Activity {
 
                     int id = 0;
 
+                    final ScaleUser scaleUser = new ScaleUser();
+
+                    scaleUser.setUserName(name);
+                    scaleUser.setBirthday(birthday);
+                    scaleUser.setBodyHeight(body_height);
+                    scaleUser.setScaleUnit(scale_unit);
+                    scaleUser.setGender(gender);
+                    scaleUser.setConvertedInitialWeight(initial_weight);
+                    scaleUser.setGoalWeight(goal_weight);
+                    scaleUser.setGoalDate(goal_date);
+
                     if (getIntent().getExtras().getInt("mode") == EDIT_USER_REQUEST) {
                         id = getIntent().getExtras().getInt("id");
-                        openScale.updateScaleUser(id, name, birthday, body_height, scale_unit, gender, initial_weight, goal_weight, goal_date);
+                        scaleUser.setId(id);
+                        openScale.updateScaleUser(scaleUser);
                     } else {
-                        openScale.addScaleUser(name, birthday, body_height, scale_unit, gender, initial_weight, goal_weight, goal_date);
+                        openScale.addScaleUser(scaleUser);
 
                         id = openScale.getScaleUserList().get(openScale.getScaleUserList().size() - 1).getId();
                     }
diff --git a/android_app/app/src/main/java/com/health/openscale/gui/fragments/OverviewFragment.java b/android_app/app/src/main/java/com/health/openscale/gui/fragments/OverviewFragment.java
index e8c8dc27..ca76de13 100644
--- a/android_app/app/src/main/java/com/health/openscale/gui/fragments/OverviewFragment.java
+++ b/android_app/app/src/main/java/com/health/openscale/gui/fragments/OverviewFragment.java
@@ -215,7 +215,7 @@ public class OverviewFragment extends Fragment implements FragmentUpdateListener
         userSelectedData = null;
 
         spinUserAdapter.clear();
-        ArrayList<ScaleUser> scaleUserList = OpenScale.getInstance(getContext()).getScaleUserList();
+        List<ScaleUser> scaleUserList = OpenScale.getInstance(getContext()).getScaleUserList();
 
         int posUser = 0;
 
@@ -480,7 +480,7 @@ public class OverviewFragment extends Fragment implements FragmentUpdateListener
              if (parent.getChildCount() > 0) {
                  ((TextView) parent.getChildAt(0)).setTextColor(Color.GRAY);
 
-                 ArrayList<ScaleUser> scaleUserList = OpenScale.getInstance(getContext()).getScaleUserList();
+                 List<ScaleUser> scaleUserList = OpenScale.getInstance(getContext()).getScaleUserList();
 
                  ScaleUser scaleUser = scaleUserList.get(position);
 
diff --git a/android_app/app/src/main/java/com/health/openscale/gui/preferences/UsersPreferences.java b/android_app/app/src/main/java/com/health/openscale/gui/preferences/UsersPreferences.java
index 965c65b7..0e5bc1af 100644
--- a/android_app/app/src/main/java/com/health/openscale/gui/preferences/UsersPreferences.java
+++ b/android_app/app/src/main/java/com/health/openscale/gui/preferences/UsersPreferences.java
@@ -27,7 +27,7 @@ import com.health.openscale.core.OpenScale;
 import com.health.openscale.core.datatypes.ScaleUser;
 import com.health.openscale.gui.activities.UserSettingsActivity;
 
-import java.util.ArrayList;
+import java.util.List;
 
 import static android.app.Activity.RESULT_OK;
 
@@ -50,7 +50,7 @@ public class UsersPreferences extends PreferenceFragment {
 
         OpenScale openScale = OpenScale.getInstance(getActivity().getApplicationContext());
 
-        ArrayList<ScaleUser> scaleUserList = openScale.getScaleUserList();
+        List<ScaleUser> scaleUserList = openScale.getScaleUserList();
 
         for (ScaleUser scaleUser : scaleUserList)
         {