Diet quality is being used a lot lately in many documents, however there is no official definition that I have been able to find only the following on balanced diet. Balanced Diet A balanced diet is a diet that provides energy and all essential nutrients for growth and a healthy and active life. Since few foods contain all the nutrients required to permit the normal growth, maintenance and functioning of the human body, a variety of food is needed to cover a person’s macro and micronutrient needs. Any combination of foods that provides the correct amount of dietary energy and all essential nutrients in optimal amounts and proportions is a balanced diet. Source: Coming to Terms with Terminology. Committee on World Food Security. Thirty-ninth Session Rome, Italy, 15-20 October 2012. Item V.a