What's the relation between visceral fat and organ fat?

Visceral fat and organ (intra-abdominal) fat are closely related but distinct in their locations and the potential health risks they pose.

1. Location and Composition: Visceral fat is stored within the abdominal cavity and is packed in between internal organs like the liver, pancreas, and intestines. This type of fat is different from subcutaneous fat, which is found beneath the skin.

2. Health Risks: Visceral fat is particularly concerning due to its proximity to vital organs and its metabolic activity. It drains directly into the portal vein, carrying fatty acids to the liver, which impacts liver function and insulin action. This contributes significantly to metabolic syndrome, which includes conditions like diabetes, high blood pressure, and heart disease 1.

3. Impact of Stress and Cortisol: Visceral fat can be influenced by cortisol levels, which are elevated by stress. Cortisol promotes the storage of visceral fat, making it an active player in stress-related weight gain. This is evident in cases such as major depressive disorder, where patients lose subcutaneous fat while gaining visceral fat due to high cortisol levels 1.

Understanding these associations between visceral and organ fat is crucial for addressing related health risks effectively and adopting appropriate lifestyle and medical interventions.

The process by which organs can no longer efficiently handle insulin, which then leads to spillover into other fat stores such as visceral fat, occurs as part of the progression towards insulin resistance and type 2 diabetes. Here's a detailed explanation from the Huberman Lab:

1. Insulin Resistance Development: Initially, tissues such as muscle and liver become less responsive to insulin's effects. The pancreas responds by producing more insulin to manage glucose levels. Over time, the amount of insulin needed increases as the body's response continues to diminish.

2. Progression to Type 2 Diabetes: As insulin resistance worsens, the liver becomes affected as well. This organ normally helps regulate glucose levels in the blood, but when it becomes insulin resistant, it incorrectly releases too much glucose. At the same time, muscle tissues fail to adequately absorb and utilize glucose, leading to further elevations in blood glucose levels.

3. Impact on Pancreas: Simultaneously, fat begins to accumulate abnormally, not just in typical fat stores but also in the muscles, liver, and notably in the pancreas itself. This fat accumulation within the pancreas leads to inflammation and dysfunction of the pancreatic beta cells, the cells responsible for insulin production.

4. Need for Exogenous Insulin: Eventually, the pancreas may become so impaired that it can no longer produce adequate insulin, necessitating the introduction of insulin therapy from external sources to manage blood glucose levels.

This cascade, exacerbated by factors like physical inactivity, sleep deprivation, and an energy imbalance, leads to severe metabolic disruptions, including the "spillover" of insulin to other fat stores like visceral fat 1.