1) A household includes all persons living under the same roof who share meals.
2) As opposed to IDDS, which uses 7 or 9 food groups, HDDS works with 12 food groups (for details, see FAO's guidelines below).
3) HDDS is prone to seasonal differences. Do your best to collect baseline and endline data at the same time of a year; otherwise, it is very likely that they will not be comparable. Do not collect data during fasting periods, such as pre-Easter time or Ramadan.
4) Do not include foods that were purchased and eaten outside the home. These foods are excluded because the respondent may not know the foods which other household members purchased and ate outside the home. You can include foods that were 1) prepared in the home and consumed in the home or outside the home; or 2) purchased or gathered outside and consumed in the home. Due to this reason, the HDDS indicator should not be used in contexts where eating outside the home is very common.
5) When training the data collectors, practice extensively which meals belong to which food group (allocate at least 3 hours full of examples and exercises). For example, while pumpkin flesh belongs to Vitamin A Rich Foods, pumpkin leaves belong to Dark Green Leafy Vegetables (see more examples in the FAO Guidelines below). If your questionnaire includes examples of different foods per each group, adjust them to the local context.
6) Do not record foods in quantities lower than one teaspoon (for example, a small amount of fish powder added for flavouring).
For more tips, read FAO's Guidance on HDDS (see below).