In the May edition of Nutrition Action Health Letter the cover story was Food and Addiction – Can Some Foods Hijack the Brain? (1). In light of the Institute of Medicine’s report on Accelerating Progress in Obesity Prevention: Solving the Weight of the Nation and the corresponding discussion of obesity management, treatment, and policies, we thought it would be interesting to explore the idea of “Food Addiction” more closely.
Clearly obesity is a multifaceted disease but could “Food Addiction” play a role? If so, how can we manage it?
What Types of Foods are Addictive? Research into the addictive properties of foods is still in its infancy; however, it seems to be gaining momentum in the scientific community. The justification for the concept of food addiction comes from the observation that food can be abused in the same way as other addictive substances. All foods are not equal when it comes to food addiction though. The hyper-palatable foods (really tasty and unfortunately high in calories, sugar, fat and salt!) are more likely to be abused than the traditional, unprocessed foods, which our ancestors consumed (2). The food industry would like us to purchase and consume their foods – obviously – and encourage us to do so by creating hyper-palatable foods that encourage overeating. The primary culprits seem to be fat and sugar. This is logical if you think of the foods people typically crave!
There is a paucity of human research in this area but animal studies do find that feeding rats high sugar and fat diets affects their brains in a similar way to other drugs and leads to increases in food intake (3). It also appears that eating high-fat, high-sugar foods on a regular basis can change how the brain responds to a food stimulus making it necessary to eat more to get the same “high” (1).
Who Might Have Food Addiction? Interestingly it appears that not everyone responds to food in the same way and not everyone experiences food addiction. A study in obese women found they were more responsive to food rewards than their lower body weight counterparts (4). Gearhardt et al. (5) have developed the Yale Food Addition Scale (YFAS) to measure food addiction. They suggest their scale is appropriate because YFAS scores correlated with increased brain activity in the area that plays a role in cravings and reduced inhibitory control (6).
Davis et al. (7) administered the YFAS to 72 obese adults and found that 18 of them met the “diagnostic” criteria for food addiction. While they didn’t find significant differences in BMI between the food addicts and non-food addicts, they did find that the food addicts were more likely to eat for emotional reasons, display hedonic eating, and binge eat. They suggest that food addiction should be viewed like other addictions because of three common characteristics:
- Clinical co-morbidities – those with food addiction also experienced more binge eating disorder, depression, and ADHD.
- Psychological risk factors – those with food addiction were more impulsive and scored higher on addictive personality traits.
- Abnormal motivation for the addictive substance – those with food addiction showed stronger food cravings and were more responsive to the hedonic impact of food (7).
Importantly, food addiction is quite different than a craving. Craving a food on occasion is entirely normal; whereas, food addiction refers to a relatively small percentage of the population that experiences pronounced cravings, loss of control and compulsive overeating.
Practically what does this mean? No Baloney thinks it should affect how we look at and treat obesity. Often we tend to focus entirely on caloric restriction and exercise, and while these are important outcomes when treating obesity, it is important to understand WHY people are over-eating and not exercising and try to get at the root cause. Often treating the underlying condition(s) will help people achieve a healthier lifestyle; of course, a multidisciplinary approach with psychological counselling when appropriate is imperative for success. It also highlights the importance of a healthy diet at a young age to prevent changes in the brain that encourage high intakes of calorie laden junk foods.
1. Food and addiction: can some foods hijack the brain? Nutrition Action Health Letter 2012; 39(4):3-7.
2. Armelagos GJ. The omnivore’s dilemma. The evolution of the brain and the determinants of food choice. Journal of Anthropological Research 2012; 66:161-185.
3. Egecioglu E, et al. Hedonic and incentive signals for body weight control. Rev Endocr Metab Disord 2011; 12(3):141-151.
4. Stoeckel LE, et al. Widespread reward-system activation in obese women in response to pictures of high-calorie foods. Neuroimage 2008; 41(2):636-47.
5. Gearhardt AN, Corbin WR, Brownell KD. Preliminary validation of the Yale Food Addition Scale. Appetite 2009; 52:430-436.
6. Gearhardt AN, Yokum S, Orr PT, Stice E, Corbin WR, Brownell KD. Neural correlates of food addiction. Archives of General Psychiatry 2011; 32:E1-9.
7. Davis C et al. Evidence that ‘food addiction’ is a valid phenotype of obesity. Appetite 2011; 57:711-717.