What is lipogenesis
Have you heard of the term lipogenesis? Well, it simply describes the process of formation and building up of fat inside one’s body. Scientifically put, (direct quote) “a process of fatty acid and triglyceride synthesis from glucose or other substrates…” The body stores the excess carbs as fatty acids (fat) using a difficult and inefficient process called de novo lipogenesis. Simply put, if you consume too much carbohydrates, more than your daily caloric requirements, the body will use the process of lipogenesis to store them as fat.
Actually your body preferentially burns the carbs and stores the excess calories from fat in the adipose (fat) tissue.
If you are consuming too much carbs and/or too much fat, the body stimulates the process of lipogenesis and stores the excess fat in the form of triglycerides. If you are fasting, the subcutaneous fat releases excess plasma free fatty acids which accumulate in the non-adipose tissues (like muscle, pancreas, liver, heart, etc.) in the form of triglycerides. This process may lead to cell dysfunction and apoptosis (aka cell death).
What excessive lipogenesis can do?
The excessive lipids accumulation may cause lipotoxicity, dysfunction of the cells and changes in the metabolic pathways in adipose (fat) tissue and in peripheral organs – like muscle, pancreas, liver and heart. This is a risk factor for various metabolic disorders – like obesity, fatty liver disease, diabetes, hepatocellular carcinoma and cardiovascular diseases.
De novo lipogenesis
The de novo lipogenesis is the process in which carbohydrates are converted into lipids (fats).
This process occurs because it’s easier for the body to store lipids and they are a more energy-dense molecule with more ATP (the main energy currency in the body). The de novo lipogenesis occur when the intake of carbohydrates surpasses the energy need AND when you aren’t consuming sufficient amount of fat.
The de novo lipogenesis occur in the cells of the liver (hepatocytes), in the fat cells (adipocites) primarily but can occur in most body cells.
A few side words
High intake of sugar and high intake of fat correlate with development of non-alcoholic fatty liver disease and obesity. The de novo lipogenesis may lead to hepatic lipid accumulation which may lead to non-alcoholic fatty liver disease. This process haven’t been thought to be a major factor for storing liver lipids. But the initial studies which showed that less than 5% of the stored triglycerides are derived from the de novo lipogenesis were done with subjects under fasting conditions and on lean subjects. But insulin resistant and obese patients have much higher rates of lipogenesis. Recent analysis of obese non-alcoholic fatty liver disease patients showed that 26 percent of the liver fats in those subjects came from the de novo lipogenesis. Another study showed that the de novo lipogenesis is a central factor for the non-alcoholic fatty liver disease.
Excessive lipogenesis may also lead to other health problems, mainly affecting the heart,pancreas, liver and mucles.