• New research suggests that obesity affects different parts of the brain in men and women, potentially requiring sex-specific treatment options.
  • While some brain imaging studies have shown how obesity affects eating habits, this study analyzed different types of brain scans in combination with other clinical information to compare differences between males and females with high BMI compared to those with a normal BMI.
  • The researchers found that specific parts of the brain differed between males and females with high BMI, indicating that tailoring treatments to each person’s sex may be crucial in combating obesity.

According to the researchers, it’s important to consider differences between males and females when studying obesity.

The study, published in Brain Communications, involved the analysis of data from MRI scans, clinical characteristics, and medical histories to identify sex-specific processes in the brain that lead to obesity, suggesting that men and women develop obesity for different reasons.

Previous research involving brain imaging has shown how obesity affects eating habits, but not many studies have looked at multiple types of brain imaging to see how obesity is different in males and females.

Multiple types of brain scans

The researchers used a data-driven approach using multimodal brain imaging (structure, connectivity, and function) to better understand how obesity manifests differently in the brain for women and men.

The study involved the review of data from 183 participants, including 78 with high BMI and 105 with normal BMI.

The researchers used multiple types of brain scans and surveys to collect data on mood, early life experiences, and eating habits.

They analyzed this data using a method called DIABLO to see if they could accurately tell the difference between participants with high BMI and those with normal BMI, as well as the difference between males and females with high BMI.

Males vs. females: Obesity affected by different brain parts

The analysis was able to correctly differentiate high BMI from normal BMI participants and males with high BMI from females with high BMI with 77% and 75% accuracy, respectively.

The study found differences in specific parts of the brain between males and females with high BMI, related to early life experiences, mental health, and the sense of touch.

Dr. Arpana Gupta, associate professor at the David Geffen School of Medicine at UCLA and lead author of the study, explained the background to Medical News Today, saying “in a [recently] published review of the literature, we found that all neuroimaging studies since 2010 ignored how obesity at the brain level differed between men and women.”

They found that out of 199 studies, only 13 studies looked at sex differences and 16 looked at within-sex patterns in the brain.

“This made us realize how understudied sex differences are when it comes to obesity mechanisms at the brain level,” Dr. Gupta explained.

“We know that brain signatures in the brain are altered for obese individuals as it has implications for how one views food and how this in turn leads to food cravings, altered eating patterns and in turn obesity. However, looking at differences in how these brain patterns differ by sex is a game changer as it suggests that the pathways to how women and men develop obesity are different.”

— Dr. Arpana Gupta, PhD

Compulsive eating and hunger

Dr. Gupta noted that women with obesity exhibited changes in emotion-related brain regions that were linked to higher levels of compulsive eating. Meanwhile, in men, brain regions related to eating behavior and obesity were associated with gut and visceral sensations linked to abdominal discomfort and hunger.

Medical News Today also spoke to three independent experts, who were not involved in this research, for their perspectives.

Dr. Florencia Halperin, chief medical officer at Form, a company that provides medical treatment for obesity and associated metabolic conditions, noted that the paper is interesting for two reasons:

  • First, gender differences in obesity exist, but the reasons are unclear.
  • Second, obesity has biological underpinnings, and understanding how the brains of people with obesity differ from those without could help with diagnosis and treatment.

“This study suggests that MRI-based imaging studies might be able to help us detect differences between people with obesity and those with [healthy] BMI. However, the current study has limitations. The cross-sectional nature of the study (comparing one group to another group) means we cannot in any way prove causality.”
— Dr. Florencia Halperin

“In other words, yes, they observed brain MRI differences between men and women, and based on BMI, but we do not know that it is definitely gender or BMI that explains those differences. It could be something else,” added Dr. Halperin.

Dr. Sarah-Nicole Bostan, director of Behavior Change Strategy at Signos said the research is “compelling as it nods to the age-old therapeutic question of “what works, for who, and under what conditions.”

Kelsey Costa, registered dietitian nutritionist at MIDSS, agreed, telling MNT that “the findings of this paper point towards a more comprehensive, personalized approach to weight loss which considers lifestyle factors, emotional regulation techniques, and potential vulnerability factors such as early life trauma.”

However, Costa noted two methodological issues. First, the use of BMI as a marker of obesity.

Even though there were “several noteworthy findings based on that measure [BMI], it would be beneficial to consider more accurate measurements of obesity, such as visceral adiposity or waist-hip ratio, to validate the research finding,” she said.

Second, there was missing information on most of the prominent male obesity drivers.

“Compared with men, women with high BMI had more significant alterations in their neural signatures and lower mental health scores. This suggests that females may be more vulnerable to developing food cravings, addictions, and other unhealthy ingestive behaviors,” Costa explained.

“While this insight is vitally important, questions about what drivers of obesity are most prominent in males remain unanswered,” she added.

How this may shape treatments for obesity

Dr. Halperin notes that “at this time I think these studies are thought-provoking and suggest ideas for further study, but they do not in and of themselves have implications for patients.”

Dr. Bostan agreed, highlighting the comorbidities associated with obesity.

“Given that people with high BMI report significantly greater childhood adverse events, early life trauma, anxiety, depression, visceral sensitivity (a tendency to notice bodily symptoms with hypervigilance), physical dysfunction, frequent symptoms of general sickness, and significantly lower physical and mental health-related quality of life, treatments for obesity must do better in addressing these chronic stressors which compound weight loss efforts.”
— Dr. Sarah-Nicole Bostan

“These comorbidities don’t go away on their own, but most programs for weight loss do not address these factors despite their clear influence on the brain and on a person’s day-to-day choices,” Dr. Bostan explained.

Costa concluded that “the findings of this research represent an essential step forward in developing personalized treatments for obesity.”

“The ability to predict sex-specific obesity based on neural alterations presents an opportunity to tailor treatment plans and preventive measures, particularly for females with high BMI, for which an emotional component may be especially relevant,” Costa said.

“Those that struggle with obesity should seek to gain awareness of the underlying drivers and sex-specific pathophysiology so that treatments can be tailored to their individual needs,” she added.

“In practice, this may include consulting with a dietitian to understand the role of lifestyle factors and dietary behaviors in weight control and a cognitive behavior therapist to address any emotional and stress-related issues contributing to unhealthy eating behaviors.”
— Kelsey Costa

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