Certain words can entice individuals to eat high-calorie foods, and these “food word cues” may be influenced by both stress and genetics, new data suggest.
“This research adds to a growing body of work suggesting that environmental factors, such as food advertising and stress, directly influence our brains and eating behavior and can make it difficult for some people to regulate their food intake, especially adults who are already obese, or teens who are at increased genetic risk of becoming obese later in life,” said study investigator Susan Carnell, PhD, who is an assistant professor of psychiatry and behavioral sciences at Johns Hopkins University School of Medicine in Baltimore.
Words as ‘Food Cues’
Dr Carnell, who presented findings from 2 studies at ObesityWeek 2015, said food cues come in many forms including emotions, images, smells, tastes, and food words.
Historically, it has been assumed that images or smells were stronger food cues than food words. However, because they are ubiquitous in advertising and other contexts, it appears food words may have a significant impact on eating behavior.
In the first study, Dr Carnell and colleagues found that individuals with obesity were more likely to consume energy-dense foods compared with those with normal weight after experiencing stress. This was documented in brain imaging scans.
In addition, neural responses to high-calorie food words compared with low-calorie food words also increased for individuals with obesity under both stressed and non-stressed conditions.
In this study, the researchers enrolled 17 individuals with obesity and 12 individuals with normal weight. All volunteers underwent a functional magnetic resonance imaging (fMRI) scan during which they viewed words describing high-calorie foods, low-calorie foods, and non-foods, and rated how much they wanted to eat each food item.
The researchers found that individuals with obesity had a stronger response to words such as chocolate spread and chicken wings in a widespread neural circuit spanning multiple areas of the brain.
Moreover, the researchers found that when they subjected the volunteers to a combined social and physiological stressor, both individuals with obesity and those with normal weight showed slightly altered responses to high-calorie food words.
“We should be aware that maintaining a healthy body weight is more difficult for some people than others, and those that struggle need sympathy and practical support to help them manage their responses rather than blame. The good news is that brain responses and behavior are definitely malleable. So, obese individuals and those at high obesity risk should not give up hope. They are not doomed to become or stay obese,” Dr Carnell told Endocrinology Advisor.
Role of Genetics
In the second study, the investigators identified an association between higher genetic risk for obesity in teenagers based on several known obesity-associated genetic variants and subjective responses to food words.
The study revealed that 1 specific genetic variant (MC4R) was associated with greater intake of high-calorie foods during a laboratory test meal (P=.036), while another (FTO) was associated with lower scores on a questionnaire measuring self-regulation of food intake (P=.044).
Dr Carnell noted that tiny differences in our genome affect how we interact with the surrounding environment. She said while some of the genetic variants may have helped individuals maintain a healthy body weight in the past, they could now be working against them and making certain individuals more susceptible to obesity and diabetes.
For this investigation, Dr Carnell and her team genotyped 35 adolescents aged 14 to 19 years with varying familial risk for obesity. The cohort included 20 girls and 15 boys. The researchers assessed the subjective appetite responses to food and non-food words.
Dr Carnell said these two studies could help the clinical research community identify new behavioral treatment strategies based on reducing the impact of food cues, particularly for those at high risk for obesity.
“Endocrinologists should care because these findings highlight how vulnerable some of their patients are to even minimal prompts to eat in the environment, such as seeing food words on food menus or food advertising, which may tempt them to overeat,” said Dr Carnell.
“Obese patients or those who have a genetic predisposition for gaining weight may be particularly vulnerable. Stress could also contribute to obesity, potentially causing some of [endocrinologists’] patients’ brains to respond differently to food cues in the environment, and to overeat when given the opportunity.”
She said it may help individuals who are obese or could be at high genetic risk for becoming obese to change their immediate food environments.
“For example, if they know when they look at a restaurant menu they’ll be tempted to eat something unhealthy, they could bypass the menu by asking the server to only describe the healthiest options. They may also want to avoid fast food restaurants with lots of these choices available, and bring in their own healthier foods for lunch at work, for example,” said Dr Carnell.
Also, if patients have a history of overeating unhealthy foods when stressed, clinicians may want to give patients advice on stress reduction and stress management, according to Dr Carnell. In addition, she said clinicians should help patients to be aware of this tendency so they can spot it when it happens and try to take action.
Dr Carnell suggests that these individuals learn coping mechanisms, like talking to a friend of eating, listening to music, meditating, or going for a walk.
- Carnell S. Abstract T-OR-2103. Neural Responses to Food Words in Obese and Lean Individuals Under Stressed and Non-Stressed Conditions.
- Benson L, Pryor K, Lohse B, Geliebter A, Chung W, Carnell S. Abstract T-P-3060. Genetic Obesity Risk and Appetite in Adolescents. Both presented at: ObesityWeek 2015; November 2-6, 2015; Los Angeles.