A study published in NeuroImage has found a network of brain connections that are in-sync with the contractions of the gastro-intestinal tract and that connectivity in this brain network is associated with predictability of weight loss success.

The research was conducted by Gidon Levakov and team at Ben-Gurion University of the Negev, in Israel. 

When an individual is hungry or full, the digestive tract communicates this information with the brain via nerves. When digestion occurs in the stomach, the stomach muscles emit electrical signals in order to contract and churn the food exposing the surface area to digestive chemicals. The hungrier a person is, the more powerful these stomach contractions become.

Specific brain networks send electrical signals in an organized and interconnected fashion between different regions of the brain. Previous research has linked electrical activity emitted from the stomach muscles contracting during digestion to the sensory and motor resting-state networks in the brain.

The primary focus of the current research was to identify brain connections that form networks associated with electrical activity emitted during stomach contractions. The researchers were also interested in examining the extent to which brain connectivity can predict one’s ability to lose weight after a lifestyle intervention such as dieting or exercise.

It was hypothesized that a specific brain network is active and that these interconnections sync with electrical signals from stomach muscles (via cranial nerves) thereby predicting one’s ability to successfully lose weight.

Participants were recruited based on waist circumference, levels of fat in their blood, and age.  They were divided into three groups which would receive different types of interventions: 

• i) physical activity

• ii) physical activity and a Mediterrian diet

• iii) physical activity, Mediterrian diet and supplements of antioxidant compounds

Weight of the participants was measured at the start of the experiment and after six months of weight loss intervention. Weight loss was reported as the percent of the weight participants decreased from their starting weight.

Magnetic Resonance Imaging (MRI) was used to identify a specific resting-state network that correlates with the electrical signal from stomach muscle contractions. 

From the MRI data they collected, the researchers identified a specific subnetwork involving the sensory and motor cortices that, based on size and position in the brain, was associated with future weight loss success following a diet intervention. This effect was found the same across all three interventions.

The researchers speculate that success of weight loss following six months of dietary and physical interventions relies on connectivity patterns between cortical areas, and sensory and motor regions. The signals sent throughout the subnetwork correspond with the timing and location of stomach muscle contractions and thus predict future weight loss. 

This study provides evidence of a brain-gastric network that is associated with successful weight loss and that sensory and motor cortices are influenced by electrical signals from the digestive tract.