Personalised 'his and hers' anti-obesity pills could be on the horizon, according to new research. Scientists have discovered "sex-specific" brain signals that cause men and women to eat too much.
They combined data from MRI (magnetic resonance imaging) scans with patients' clinical features and individual histories. Senior author Dr Arpana Gupta, of the University of California, Los Angeles, said: "We found differences in several of the brain’s networks associated with early life adversity, mental health quality, and the way sensory stimulation is experienced.
"The resulting brain signatures, based on multimodal MRI imaging, may help us more precisely tailor obesity interventions based on an individual's sex."
The first study of its kind could shed fresh light on why women are more likely to be obese. In England, the rate is slightly higher - 29 percent as opposed to 27 per cent for men. In many countries the gender gap is much greater.
Previous research by the same team found emotion-related and compulsive eating appear to play a major role in obesity in women. Men's eating behaviour tends to be affected by a greater awareness of gut sensations and visceral responses – those related to abdominal discomfort.
The latest results reveal differences in brain structure, function and connectivity. For example, alterations in certain neuronal networks suggest women with a high BMI (body mass index) are more drawn to highly processed foods.
It increases the risk of developing cravings for burgers, ice cream, biscuits and cakes. Dr Gupta said: "In designing treatment plans for females with high BMI, it may be important to focus on emotional regulation techniques and vulnerability factors."
The 183 study participants were aged 18 to 55 - almost half of whom were obese. They filled out a battery of self-report questionnaires assessing childhood trauma, anxiety and depression, visceral sensitivity, food addiction, bowel symptoms, personality traits, and many other factors.
Each participant also underwent three different brain MRIs to assess structure, function and connectivity. Data sets from the three scans and from clinical information were analysed using an analytical tool that seeks to identify a limited number of variables from multiple data sets to predict an outcome.
The results show specific network connectivity changes associated with high BMI, regardless of sex. In females, the study identified brain regions and networks with alterations associated with early life trauma. These appear consistent with previous observations that females with obesity, compared to males, may have greater anxiety, lower resilience and difficulty integrating emotions with action-directed goal planning.
Females also may be more susceptible to the sight, smell and taste of ultra-processed foods. Added Dr Gupta: "Although causality is unknown, the strong associations between clinical markers, such as anxiety, depression, obesity and neural signatures suggest the importance of the bidirectional mechanistic connection of the gut-brain axis." The study is published in the journal Brain Communications.
