What is food reward? How do we measure it? How does food reward relate to appetite control and obesity?  These are some of the questions that researchers in the NBU are currently investigating.

In broad terms, reward is believed to comprise distinguishable psychological components known as “liking” and “wanting”. Liking is essentially a hedonic reaction to the pleasure of a reward (e.g., the palatability of food). Wanting is an explicit and implicit motivational component of reward (e.g., disposition to eat). An ongoing programme of research in the NBU has sought to identify the neurobiological underpinnings of food reward in human volunteers. In a recent study, we used a dietary manipulation (acute tyrosine-phenylalanine depletion) to induce short-term decreases in levels of the neurotransmitter, dopamine, and we measured the resultant effects on appetite, food reward and intake (Hardman et al., 2012). Results indicated that the depletion had a selective effect on appetite ratings (an index of the motivational value of food) in the absence of any effect on liking for food. These findings support the theory that dopamine mediates wanting, and that this is a distinct neural mechanism relative to systems that underlie liking.

In related studies, we are developing novel measures of food reward and its separate components, liking and wanting. These include simple rating scales and behavioural tasks. We are also interested in the extent to which these measures can predict food choice and consumption and hence be associated with disordered eating and obesity.

Relevant peer-reviewed papers:

• Rogers, PJ & Hardman, CA 2015, 'Food reward. What it is and how to measure it' Appetite, vol 90, pp. 1-15. Click here to read
• Hardman, CA, Rogers, PJ, Dallas, R, Scott, J, Ruddock, HK & Robinson, E 2015, '"Food addiction is real". The effects of exposure to this message on self-diagnosed food addiction and eating behaviour' Appetite, vol 91, pp. 179-184. Click here to read
• Hardman, CA, Rogers, PJ, Timpson, NJ & Munafo, MR 2014, 'Lack of association between DRD2 and OPRM1 genotypes and adiposity' Internat. J. Obesity, vol 38, no. 5, pp. 730-736., Click here to read
• Hardman, CA, Herbert, VMB, Brunstrom, JM, Munafò, MR & Rogers, PJ 2012, 'Dopamine and food reward: Effects of acute tyrosine/phenylalanine depletion on appetite' Physiology and Behavior, vol 105, no. 5, pp. 1202 - 1207. Click here to read