Google Fitness API returns only {} as result

Question

Here am not getting any error, but I didnt get any result from the Google fit. Am trying to getting Google Fit values for third user(example1@gmail.com). User(AuthUser@gmail.com) profile are getting properly and access token valid. But while trying to get the third party user (example1@gmail.com) and Auth user (AuthUser@gmail.com) information it show only {} as result. Any one can help me to get the fitness values from Google Fit.

    //oauth2Client.js
    getAccessToken(oauth2Client, function() {
      // retrieve user profile
      plus.people.get({ userId: 'me', auth: oauth2Client }, function(err, profile) {
        if (err) {
          console.log('An error occured', err);
          return;
        }
        var token;
        if(oauth2Client.credentials.refresh_token != null){
          token=oauth2Client.credentials.refresh_token;
        }
        else{
          token=oauth2Client.credentials.access_token;
        }
        fit.users.dataSources.list({'userId':'me','token':token,'email':'example1@gmail.com'}, function(err, result) {
          console.log(err);   // it returns only null
          console.log(result); //it returns only {}
        });
        console.log(profile.displayName, ':', profile.tagline);
      });
    });

//fitness.js
          list: function(params, callback) {
            var parameters = {
              options: {
                url: 'https://www.googleapis.com/fitness/v1/users/{userId}/dataSources?access_token={token}',
                method: 'GET'
              },
              params: params,
              requiredParams: ['userId','token'],
              pathParams: ['userId','token'],
              context: self
            };
            return createAPIRequest(parameters, callback);
          },