Smartphones are used by incredibly many people, and in 2011 there where a total of 491.4 million units soled worldwide. This makes it a relevant technique for performing dietary studies when the test patients are on the move. This thesis shows how to create a back end environment for an Android application with existing techniques linked together, using MSSQL database, Visual Studio Web Service, web pages and C# classes and ASP.NET security. The back end development is used in a dietary study on Gothenburg University, butcould be applied on many similar back end projects using databases and server development.Techniques used in this thesis are: REST (Representational State Transfer) -client implementation and development inside the Android application, using HTTP methods to set and get information from the server and database, and JSON-format to read and transferinformation in an easy and understandable way, both from the Android application and from the database. FileMaker is also used in this project as a third part programme tovisualise the information in the database.