Food frequency questionnaire (FFQ) sum scores
- Recognizable in the data as sec_c_ffq
- FFQ sum scores wiki page
- Required reference: Siebelink, Els, Anouk Geelen, and Jeanne HM de Vries. "Self-reported energy intake by FFQ compared with actual energy intake to maintain body weight in 516 adults." British journal of nutrition 106.2 (2011): 274-281.