Mitochondria are the “powerhouses” of our cells. Their main job is to burn nutrients (primarily carbohydrates and fats) from food to produce energy.
In a healthy person, this process is efficient and well-regulated. However, in people with overweight or obesity, this energy-producing machinery begins to fail in key tissues.

Adipose Tissue (Fat): Fat cells (adipocytes) not only store energy but are also metabolically active.
In obesity, an excess of nutrients — especially a high-fat diet — can overload the mitochondria in these cells. This leads to dysfunction, reducing their capacity to burn fat.
As a result, fat accumulates further, and the adipose tissue becomes inflamed — a state known as chronic low-grade inflammation, a hallmark of obesity.

Skeletal Muscle: Skeletal muscle is the body’s main energy consumer at rest and during physical activity.
In obesity, mitochondria in muscle cells show lower efficiency, reducing their capacity to oxidize or “burn” fats.
This leads to lipid buildup in muscle tissue, which is directly linked to insulin resistance — a condition in which cells do not respond well to insulin and cannot efficiently absorb glucose from the blood, potentially leading to type 2 diabetes.

Liver: Similar to liver disease, obesity can lead to fat accumulation in the liver (non-alcoholic fatty liver disease).
Mitochondria in liver cells are also compromised, impairing their ability to process and burn fat, which perpetuates the disease.