Data on the impact of national FBDGs is still limited, as very few countries conduct regular monitoring and evaluation of related programmes and policies. Evaluation is not only needed to “see results” but also for accountability, to see what works and what doesn't, and to support the evidence base.  

For FBDGs, the outcomes measured would depend on the type and duration of the intervention. A set of indicators may be chosen to measure impact in the short, medium and long-term.

• Short term indicators could include changes in knowledge and attitudes of the population, health professionals, decision makers and the food industry relative to the dietary guidelines.
• Medium term indicators could include increased availability and accessibility to the foods recommended; use of the dietary guidelines to set standards in public settings as a basis for developing food, agriculture and nutrition policies and programmes.
• Long term indicators could include changes in household or commercial food production, consumption trends and dietary intake. Health outcomes, including biochemical indicators may be appropriate in assessing the effectiveness of dietary guidelines in some circumstances.