Food preferences and taste sensitivity study
July 27, 2011
At the beginning of the year we requested people complete a questionnaire about the food preferences and responses to food. The individuals were either pre-surgery, post-surgery or from the general population. The research developed from past findings from a number of previous studies with individuals who were overweight and/or unsuccessful dieters. Evidence indicates that certain things appear to predict whether people are over-weight/obese and have difficulty achieving and maintaining weight-loss. Emotional eating is the most robust behavioural trait that is apparent and it is where people over-eat or undertake binge eating as a direct response to a particular emotion, for example, sadness, boredom etc. Other research has shown that food in the environment has a more powerful effect on certain people. This means that just seeing or knowing food is available can create a greater motivational drive to eat. This behaviour is thought to be subconscious which requires a conscious act to resist it. Finally in relation to peoples liking of food, here the evidence is of no difference between people with regard to liking or disliking high and low fat food tastes. What does appear to be the case is that following surgery this changes. The change is thought to be either a result of negative surgery side-effects, or changes in taste perception. The purpose of the study was to see if surgery itself affects people’s responses and preferences and also whether we can use a technique to manipulate people’s subconscious responses to help them remain closer to their conscious goal of losing weight. The findings do appear to show the power of food could be affected in some areas.
Results Summary
The results of the research with the post-surgery participants are encouraging. In this part of the study half of the post-surgery group were required to focus on how much they had invested, personally, socially, financially and physically in having undertaken weight-loss surgery. Those individuals in this group had significantly different responses in some of the areas than the other post-surgery participants. The power of food over individuals was greatly reduced for the investment group both overall and specifically in responses to situations where food was known to be available. In addition there was a clear change in food preference too. The investment group had the greatest dislike of all groups for high-fat foods and had a significantly greater liking of low-fat foods than the other post-surgery participants. The findings indicate that by focusing on their personal investment in weight-loss surgery people’s subconscious response to food, (foods’ power), was minimised and their weight-loss goal remained at the forefront. When weight-loss in the two groups was compared after 3months, the standard post-surgery group had lost on average a further 2lbs; the investment post-surgery group had lost on average a further 14lbs. It is far too early to say that it is the investment task that caused the difference in weight-loss but it is an encouraging outcome. The theory behind the results is that by focusing on what you have put in to a task, in this instance having surgery, it would create “cognitive dissonance”, (or conflict in the mind), if subsequent thoughts and behaviours did not match. If this theory is the case, then possibly it can be used to help people maintain their conscious cognitive goal of losing and maintaining weight-loss at the same time as minimising what is perhaps a more natural tendency which motivates their eating behaviour.
The study did not finding a significant difference in people’s responses to food before and after surgery although there was a reduction in response in all areas. This may indicate that surgery does have an effect - but that we didn’t find it! This could be because the sample of people in the study was small (very few pre-surgery participants decided to complete the questionnaire which restricted our options a bit) or the alternative is that the effect of surgery is small and does not last very long. What was clear however was that post-surgery participants disliked all food types, high and low-fat a lot more than both the general or pre-surgery groups. This provides support for the previous findings but does not still confirm exactly why – although the fact that liking of all food was greatly reduced would I believe indicate it is the generally negative side-effects of eating following surgery that is the cause, as it would appear improbable that all taste perception is altered negatively but some clear change in peoples relationship with eating food occurs. This is not a positive change as although a decrease in preference for sweet and fatty foods may be healthy; the intense dislike of low-fat foods does not help in achieving maintenance of weight-loss long-term. Emotional response to food was not affected in any of the three surgery groups and was stronger in comparison to the general group which further indicates how robust an effect emotion is on eating habits. There needs to be a focused effort on helping people either anticipate their behaviour response and/or prevent situations where trigger emotions occur.
This is only a brief summary but hopefully explains what it was people took part in at the beginning of the year! If people have any particular comments or anyone wants to remain in our participant bank for future research studies and they have not already contacted me please let me know.
Thank you again to all those individuals who took the time to participate, your help is appreciated.
Margaret Husted email: mh00227@surrey.ac.uk