Is ‘Food Addiction’ a Subtype of Obesity?

Yesterday, I posted on the recent Senate Committee call on the FDA to ease the path to approval of new obesity, which it described as “a significant unmet medical need.”

In my commentary, I suggested that one solution to better balancing risk and benefit would be to subcategorize obesity into meaningful subtypes, ideally based on an objective aetiological framework.

In a paper just published in Appetite, Caroline Davis and colleagues from Toronto’s York University provide evidence suggesting that ‘food addiction’ (FA) may be a valid clinical sub-phenotype of obesity.

The researchers examined the validity of the Yale Food Addiction Scale (YFAS) – the first tool developed to identify individuals with addictive tendencies towards food – in a sample of obese adults (aged 25-45 years) and non-obese controls.

The YFAS is available here – the instruction sheet for interpreting the test is available here.

In their analysis, the researchers focused on three domains relevant to the characterization of conventional substance-dependence disorders: clinical co-morbidities, psychological risk factors, and abnormal motivation for the addictive substance.

Not only were their results strongly supportive of the ‘food addiction’ construct demonstrated validity of the YFAS, in addition, those who met the diagnostic criteria for food addiction had a significantly greater co-morbidity with Binge Eating Disorder, depression, and attention-deficit/hyperactivity disorder compared to their age- and weight-equivalent counterparts.

Those with FA were also more impulsive and displayed greater emotional reactivity than non-FA obese controls. They also displayed greater food cravings and the tendency to ‘self-soothe’ with food.

As the authors conclude:

“These findings advance the quest to identify clinically relevant subtypes of obesity that may possess different vulnerabilities to environmental risk factors, and thereby could inform more personalized treatment approaches for those who struggle with overeating and weight gain.”

From a treatment perspective, these would be the patients, who would perhaps be most responsive to behavioural and pharmacological treatments aligned with an addiction paradigm.

In contrast, non-food addicted obese individuals will likely be far less responsive to these approaches.

Thus, while it may make sense to expose individuals with food addiction to drugs like buproprion, naltrexone, or rimonabant, non-addictive obese individuals may neither respond well nor warrant the risk of these drugs for treating their obesity.

As long as we continue on the path to developing obesity treatments using an outdated and simplistic ‘let’s-get-anyone-with-a-BMI-higher-than-X-to-lose-weight’ approach, we will never get a good handle on risk benefit ratios, let alone, get any closer to ‘aetiology based’ treatments.

Lisbon, Portugal

Davis C, Curtis C, Levitan RD, Carter JC, Kaplan AS, & Kennedy JL (2011). Evidence that ‘food addiction’ is a valid phenotype of obesity. Appetite PMID: 21907742