I am undertaking a study which has the following aims:
The main aim of the current study is to investigate the effects of food messages about the healthiness of foods on actual food intake.
Additionally, a secondary aim is to discover the extent to which impulsivity/sensation seeking, taste preference and BMI may moderate/mediate the effects of food-related messages on food intake.
I am not sure which is more appropriate in this case to mediate or moderate. My DV is food consumption and IV's are food messages, impulsivity/sensation seeking, taste preference and BMI.
It is an experimental study which involves three treatment groups which will receive either a healthy message, unhealthy message or no message about the cookie. They will be asked to taste and rate and consume 'cookies'. The taste rating will also ask questions about taste preference. I will then provide a questionnaire which gathers info about impulsivity/sensation seeking and also BMI.
I am leaning towards mediation but am not sure. I believe that those in the healthy message group will consume more cookies based on prior research but I also deem that the other variables will have a influence as well on cookie consumption. Basically those who have high impulsivity, taste preference for the cookie and higher BMI either individually or in combination will consume more cookies.
So I am not sure as I've indicated whether it would be more suitable to have moderator's or mediators. I am somehow leaning towards mediation but would like some clarity around this.
Also if it's either mediation or moderation which IV's are which? Also what would a hypothesis look like?
I am guessing that if I went with moderation for example then a hypothesis may look something like:
the relation between health message and cookie consumption could be stronger for those who score higher on the impSS as compared to those who don’t score as high
But I may be wrong. Any help would be appreciated.