By John M. de Castro, Ph.D.
“But whether or not you are predisposed to hedonic eating because of your genetics, everyone could benefit by becoming more mindful of what they eat, how much they eat, and when they eat.” – Tim Boyer
Obesity has become an epidemic in the industrialized world. In the U.S. the incidence of obesity, defined as a Body Mass Index (BMI) of 30 or above has more than doubled over the last 35 years. Currently more than 2 in 3 adults are considered to be overweight or obese and around 35% of the population meets the criteria for obesity. Overweight and obesity result from an imbalance between energy intake and expenditure. At some point in their lives people who are overweight have eaten a surplus of food energy relative to the amount they’re expending. This fact has led to investigations of the drivers of overeating in hope of discovering methods to treat or prevent obesity.
Eating is produced by two categories of signals. Homeostatic signals emerge from the body’s need for nutrients and usually work to balance intake with expenditure. Hedonic eating, on the other hand, is not tied to nutrient needs but rather to the pleasurable and rewarding qualities of food. This latter form of eating appears to be related to the activity of a neural system that produces pleasure and uses opioids as its neurotransmitter. Hedonic eating releases opioids in the brain eliciting pleasure. Indeed, blocking the ability of this system to produce pleasure with drugs that block this systems activity results in a reduction in hedonic eating.
Mindful eating involves paying attention to eating while it is occurring, including attention to the sight, smell, flavors, and textures of food, to the process of chewing and may help reduce intake. Indeed, high levels of mindfulness are associated with lower levels of obesity and mindfulness training has been shown to reduce binge eating, emotional eating, and external eating. It is suspected that mindful eating counters hedonic eating. So, how well mindfulness reduces intake may reflect how well it influences the opioid system in the brain. Hence, opioid blocking responses should predict the effectiveness of mindful eating interventions.
In today’s Research News article “Acute responses to opioidergic blockade as a biomarker of hedonic eating among obese women enrolled in a mindfulness-based weight loss intervention trial.” See:
or see summary below or view the full text of the study at:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4485926/
Mason and colleagues recruited obese women (BMI 30-46) and had them complete questionnaires on nausea, binge eating, food addictions, reward based eating, mindful eating, and emotional eating. They completed these measures after ingesting a placebo pill (no active ingredients) and after a pill containing naltrexone, an opioid blocker. The effectiveness of the blocker was verified by its ability to raise salivary cortisol levels. The participants then received a 5.5-month intervention of either mindfulness training or an active relaxation and cognitive therapy control condition.
They found that the greater the pretest reward based eating drive and food addictions and the lower the mindful eating, the greater the response to the opioid blocker naltrexone, suggesting that those who are most susceptible to hedonic eating are the most responsive to blocking the opioid system. Importantly, they also found that the greater the response of highly mindful participants to the opioid blocker the greater, 6-months later, the reduction in food addiction symptoms, binge eating, and reward based eating produced by the mindfulness training.
These results suggest that the cortisol response to naltrexone is an indicator of susceptibility to hedonic eating. They further suggest that this responsiveness is predictive of the effectiveness of mindfulness training in reducing hedonic eating. These results may be useful in the future in matching the most effective treatment to the characteristics of the obese individual, with those who are the most responsive to hedonic eating the best candidates for mindful eating treatment. In that way the effectiveness of treatment in reducing intake and body weight and be maximized.
So, reduce hedonic eating with mindfulness.
“This alternative approach has been dubbed “mindful eating.” Applied to eating, mindfulness includes noticing the colors, smells, flavors, and textures of your food; chewing slowly; getting rid of distractions like TV or reading; and learning to cope with guilt and anxiety about food.” – Harvard Health Letter
CMCS – Center for Mindfulness and Contemplative Studies
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Study Summary
Mason, A. E., Lustig, R. H., Brown, R. R., Acree, M., Bacchetti, P., Moran, P. J., … Epel, E. S. (2015). Acute responses to opioidergic blockade as a biomarker of hedonic eating among obese women enrolled in a mindfulness-based weight loss intervention trial. Appetite, 91, 311–320. http://doi.org/10.1016/j.appet.2015.04.062
Highlights
- We examined acute cortisol and nausea responses to naltrexone
- Naltrexone responses were associated with measures of hedonic eating
- Naltrexone responses may identify greater opioid-mediated hedonic eating drive
- A mindfulness vs. standard weight loss program may improve food addiction
Abstract
There are currently no commonly used or easily accessible ‘biomarkers’ of hedonic eating. Physiologic responses to acute opioidergic blockade, indexed by cortisol changes and nausea, may represent indirect functional measures of opioid-mediated hedonic eating drive and predict weight loss following a mindfulness-based intervention for stress eating. In the current study, we tested whether cortisol and nausea responses induced by oral ingestion of an opioidergic antagonist (naltrexone) correlated with weight and self-report measures of hedonic eating and predicted changes in these measures following a mindfulness-based weight loss intervention. Obese women (N=88; age=46.7±13.2 years; BMI=35.8±3.8) elected to complete an optional sub-study prior to a 5.5-month weight loss intervention with or without mindfulness training. On two separate days, participants ingested naltrexone and placebo pills, collected saliva samples, and reported nausea levels. Supporting previous findings, naltrexone-induced cortisol increases were associated with greater hedonic eating (greater food addiction symptoms and reward-driven eating) and less mindful eating. Among participants with larger cortisol increases (+1 SD above mean), mindfulness participants (relative to control participants) reported greater reductions in food addiction symptoms, b=−0.95, SE(b=0.40, 95% CI [−1.74, −0.15], p=.021. Naltrexone-induced nausea was marginally associated with reward-based eating. Among participants who endorsed naltrexone-induced nausea (n=38), mindfulness participants (relative to control participants) reported greater reductions in food addiction symptoms, b=−1.00, 95% CI [−1.85, −0.77], p=.024, and trended toward reduced reward-based eating, binge eating, and weight, post-intervention. Single assessments of naltrexone-induced cortisol increases and nausea responses may be useful time- and cost-effective biological markers to identify obese individuals with greater opioid-mediated hedonic eating drive who may benefit from weight loss interventions with adjuvant mindfulness training that targets hedonic eating.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4485926/