u/ikruizinga
My earlier wording was too broad. If meal timing changes intake, that pathway can belong to the total effect of timing; a proxy affecting intake independently of timing raises a different concern about attributing the outcome to timing. An intake association alone doesn't distinguish those possibilities.
The exposure definition needs to specify both the timing behavior and its reference period. Each proxy should then be checked for links to total intake or dietary composition, since those links would weaken a timing-specific interpretation.
In the study titled “Causal relationship between dietary habits and low hand grip strength,” what period of dietary exposure is the measure intended to represent? The answer matters because a recent intake measure, a habitual pattern, and a longer term proxy address different versions of the causal question. What feature of the measure supports matching its exposure window to the timing of low hand grip strength?
