How obesity changes the brain and makes it harder to lose weight

The association between the brain and obesity has been primarily studied, but its long-term effects are still being evaluated.

“It’s not necessarily that you’re not eating enough, it’s that you’re not getting signals to the parts of your brain responsible for the positive emotions that food brings,” he says. Lizzie Davis PhD RDN, Assistant Professor of Nutritional Sciences and Director of the Dietician Education Program at the University of Alabama at Birmingham.

Experts explain that hormone levels help regulate appetite and energy.

“It is understood that important hormonal signals are affected, such as: leptin And insulin, which regulates appetite and energy homeostasis, is often dysregulated in obesity.” Doctor.Sahar TakshushChief Expert in Obesity and Obesity Medicine and Assistant Professor in the Division of Diabetes, Endocrinology, and Metabolism at Vanderbilt University Medical Center in Tennessee.

In the study, researchers conducted a controlled trial of 60 people, 30 of whom received medical treatment. obesity (BMI >30) and 30 underweight (BMI <25).During testing, participants were fed carbohydratesTo understand the direct gut-brain connection, fat, water (control) will be ingested using a nasogastric tube, a route that bypasses the mouth and is sent directly to the stomach.

All participants ate the same meal the night before the test. If participants consumed carbohydrates, fat, or water during the test, the brain was scanned by functional MRI (fMRI) and single-photon emission computed tomography (SPECT) to understand the brain’s response to these foods. Rated.

Using these testing techniques, researchers were able to understand the effects of food on different reward centers in the brain, especially an area called the striatum.

By looking at this area, the researchers found that in lean people, the striatum moves slower, and as a result, the brain understands that the body is nourished. dopamine Levels also increased, indicating satisfaction.

However, in patients with medical obesity, the striatum was sluggish, dopamine levels were not elevated, and, as a result, the brain did not recognize postprandial satiety or satisfaction.

Takshush explains that dopamine is a key neurotransmitter responsible for “the reward, motivation and pleasure systems in the brain.”

“The reward-deficiency hypothesis proposes that decreased responses of the brain’s reward system to food stimuli and obesity lead to increased food intake to achieve the same level of pleasure,” she explained.

“We thought that lean and obese people would respond differently, but we didn’t expect obese people to see so little change in brain activity,” he said. Dr. Mireille Celerylead author of the study and professor of endocrinology at Yale University School of Medicine, press release.

Medically obese patients were then asked to lose about 10% of their body weight. body weight Within 3 months – an amount already scientifically known to improve metabolism, blood sugar levels and improve overall health.

Interestingly, the participants who lost the 10% had no change in their brain’s ability to perceive feelings of fullness or satisfaction.

“Compared to the obese and 10% weight loss groups, the lean group released significantly more dopamine,” Davis said. “This is important because dopamine is a reward transmitter and signals pleasure.” do.

“This means that before and after the 10% weight loss, the lean group got more pleasure and satisfaction from the lipid infusion than the obese group,” Davis continued.

according to world health organizationOverweight or obesity kills 4 million people each year.

As medical professionals learned about the biological effects of obesity, they became more fortunate to find long-term obesity treatments.

This study leads to the idea that there may be irreversible changes taking place in the brains of medically obese people, so weight loss can be quickly regained.

Obesity is a complex concept that has many effects on the brain.

“Obesity causes a chronic low-grade inflammatory state, which is associated with altered brain function and can lead to cognitive impairment. mood disordersan increased risk of neurodegenerative diseases – this complex relationship between obesity and brain signaling is an important topic of ongoing research,” Takkouche told Healthline.

While this data and information is compelling, we still have much to learn about the brain and obesity.

“Conclusions drawn from this paper should be taken with caution as the sample size is small and the study design does not allow for causation. In other words, we cannot say that this is the cause of obesity.” Davis told Healthline.

The next step, Serlie says, is to understand when the brain does this. “We need to find out where that point at which the brain begins to lose its ability to regulate food intake and what determines that switch, because if we knew when and how that would happen , because we might be able to prevent it.”

“Losing weight is not just about ‘eat less and move more. We have,” says Takshush.

“It’s important to be patient with yourself and others.” trying to lose weight Because it can be more complicated than it looks,” she said.

Dr. Rajiv Baal is an MBA, Master’s, Physician in Emergency Medicine, Director of the Florida College of Emergency Medicine, and Health Writer.he can be found at Rajivvar MD.