[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"post-designing-a-food-frequency-questionnaire":3,"post-designing-a-food-frequency-questionnaire-author":69,"post-designing-a-food-frequency-questionnaire-related":85},{"id":4,"title":5,"author":6,"body":7,"category":68,"description":13,"excerpt":69,"extension":70,"featuredImage":69,"meta":71,"navigation":72,"path":73,"publishedAt":74,"readingTime":75,"seo":76,"stem":79,"tags":80,"__hash__":84},"blog\u002Fblog\u002Fdesigning-a-food-frequency-questionnaire.md","Designing a food frequency questionnaire that actually works","faculty-biostatistics",{"type":8,"value":9,"toc":57},"minimark",[10,14,19,22,26,29,33,36,40,43,47,50,54],[11,12,13],"p",{},"A food frequency questionnaire is the workhorse of nutritional epidemiology, and the fastest way to produce a dataset that cannot answer your research question.",[15,16,18],"h2",{"id":17},"match-the-instrument-to-the-question","Match the instrument to the question",[11,20,21],{},"An FFQ built to rank participants by usual intake of a single nutrient looks different from one intended to capture whole dietary patterns. Decide which you need before drafting a single item.",[15,23,25],{"id":24},"build-the-food-list-from-local-data","Build the food list from local data",[11,27,28],{},"Borrowing an FFQ validated in another population is a common shortcut and a common source of error. The food list must reflect what your population actually eats, in the portions they actually eat.",[15,30,32],{"id":31},"keep-the-recall-period-realistic","Keep the recall period realistic",[11,34,35],{},"Asking about the past year gives usual intake but invites recall error. Asking about the past month reduces error and captures seasonality poorly. Both are defensible; the choice needs justifying in your methods.",[15,37,39],{"id":38},"portion-sizes-need-anchors","Portion sizes need anchors",[11,41,42],{},"Photographs, household measures or standard portions all work. Free-text estimation does not.",[15,44,46],{"id":45},"validate-before-you-rely-on-it","Validate before you rely on it",[11,48,49],{},"Compare against multiple 24-hour recalls or weighed records in a subsample, report correlation coefficients by nutrient, and be transparent about which nutrients your instrument measures poorly. Every FFQ measures something poorly.",[15,51,53],{"id":52},"pilot-with-the-real-population","Pilot with the real population",[11,55,56],{},"A pilot with twenty participants from your target group will find problems that months of internal review will not: confusing item wording, missing staple foods, and the point at which people stop concentrating.",{"title":58,"searchDepth":59,"depth":60,"links":61},"",2,3,[62,63,64,65,66,67],{"id":17,"depth":59,"text":18},{"id":24,"depth":59,"text":25},{"id":31,"depth":59,"text":32},{"id":38,"depth":59,"text":39},{"id":45,"depth":59,"text":46},{"id":52,"depth":59,"text":53},"Research",null,"md",{},true,"\u002Fblog\u002Fdesigning-a-food-frequency-questionnaire","2026-05-20",10,{"metaTitle":77,"metaDescription":78,"title":5,"description":13},"Designing a food frequency questionnaire that actually works | Nexus Institute Blog","FFQs are cheap to administer and easy to design badly. What separates a usable instrument from an unusable one.","blog\u002Fdesigning-a-food-frequency-questionnaire",[81,82,83],"FFQ","dietary assessment","validation","FvoC8tdwkWP5ZGuZN9Efj1yl25BxTuK7_C00YHw5RNM",[86],{"id":87,"title":88,"author":89,"body":90,"category":68,"description":94,"excerpt":69,"extension":70,"featuredImage":69,"meta":167,"navigation":72,"path":168,"publishedAt":169,"readingTime":170,"seo":171,"stem":174,"tags":175,"__hash__":179},"blog\u002Fblog\u002Freading-a-nutrition-study-without-getting-fooled.md","How to read a nutrition study without getting fooled","faculty-research-lead",{"type":8,"value":91,"toc":159},[92,95,99,102,106,109,113,116,120,123,127,130,134,156],[11,93,94],{},"Most nutrition headlines describe a study far more confidently than the study describes itself. The gap between the two is where careers in misinformation are built — and where careful practitioners earn their credibility.",[15,96,98],{"id":97},"start-with-the-design-not-the-conclusion","Start with the design, not the conclusion",[11,100,101],{},"Before reading the abstract's final sentence, find the design. A cross-sectional survey cannot establish that a food causes an outcome, no matter how large the sample. A randomised trial can, but only for the population, dose and duration actually studied.",[15,103,105],{"id":104},"ask-who-was-studied","Ask who was studied",[11,107,108],{},"A trial in 24 young male athletes tells you very little about a 68-year-old with chronic kidney disease. Generalisability is not a technicality; it decides whether the finding belongs in your consultation at all.",[15,110,112],{"id":111},"look-for-the-effect-size-not-just-the-p-value","Look for the effect size, not just the p-value",[11,114,115],{},"\"Statistically significant\" answers whether an effect is likely to be real. It does not answer whether the effect is large enough to matter. A 0.4 kg difference over twelve months is real and clinically irrelevant at the same time.",[15,117,119],{"id":118},"check-what-was-measured","Check what was measured",[11,121,122],{},"Self-reported dietary intake carries substantial measurement error. Surrogate endpoints — a biomarker moving in the right direction — are not the same as the outcome patients care about.",[15,124,126],{"id":125},"read-the-funding-and-conflicts","Read the funding and conflicts",[11,128,129],{},"Industry funding does not invalidate a study, but it belongs in your weighting, especially where the outcome measured is unusually favourable to a single product.",[15,131,133],{"id":132},"a-working-checklist","A working checklist",[135,136,137,141,144,147,150,153],"ol",{},[138,139,140],"li",{},"What was the design, and what can it support?",[138,142,143],{},"Who was studied, and for how long?",[138,145,146],{},"How large was the effect in absolute terms?",[138,148,149],{},"Was the outcome meaningful or a surrogate?",[138,151,152],{},"Who funded it, and were conflicts declared?",[138,154,155],{},"Does it agree with the wider body of evidence?",[11,157,158],{},"If a study fails several of these, it is not evidence you should be changing practice on — it is a hypothesis someone else needs to test properly.",{"title":58,"searchDepth":59,"depth":60,"links":160},[161,162,163,164,165,166],{"id":97,"depth":59,"text":98},{"id":104,"depth":59,"text":105},{"id":111,"depth":59,"text":112},{"id":118,"depth":59,"text":119},{"id":125,"depth":59,"text":126},{"id":132,"depth":59,"text":133},{},"\u002Fblog\u002Freading-a-nutrition-study-without-getting-fooled","2026-06-18",9,{"metaTitle":172,"metaDescription":173,"title":88,"description":94},"How to read a nutrition study without getting fooled | Nexus Institute Blog","Headlines rarely survive contact with the methods section. A practical checklist for reading nutrition research critically.","blog\u002Freading-a-nutrition-study-without-getting-fooled",[176,177,178],"critical appraisal","evidence","research methods","LCmoNBnWz8TeerDqjqaQr1U4SIRTbl1eTk04WSUcmr8"]