Why is regulation of blood glucose a concern in obesity?

Weight gain in many cases leads to a state in which tissues are not able to efficiently remove glucose (sugar) from the bloodstream, and furthermore the liver may release new glucose into blood at an accelerated rate. Both of these factors lead to rising blood glucose levels and ultimately can lead to pre-diabetes and type 2 diabetes. While glucose is a carbohydrate, carbohydrate metabolism is not the only source of the metabolic problem in type 2 diabetes and pre-diabetes. The way we handle fat in the body also affects blood glucose levels by affecting how well our cells respond to insulin.

Introduction to blood lipids and which type markedly affects blood glucose

There are numerous types of fats in blood, including cholesterol, triglyceride, and free fatty acids. Cholesterol and triglyceride are often measured clinically because of their relation to heart disease risk. Free fatty acids, also referred to as non-esterified fatty acids, are another type of fat in the blood with a strong connection to health and disease risks. There is a strong connection between one’s free fatty acid levels and their blood glucose metabolism. Research in humans and laboratory animals have shown that higher concentrations and flux rates of plasma free fatty acids can impair regulation of blood glucose, leading to inefficient removal of glucose from blood alongside higher rates of glucose release into blood by the liver.

Altered free fatty acid metabolism in people with obesity

Adipose tissue (fat tissue) is the major contributor to the free fatty acid pool in the bloodstream. When the amount of adipose tissue rises during weight gain, the body’s adipose tissue accelerates its release of free fatty acids into blood. This causes excessive transport of free fatty acids to multiple organs, especially the liver, and this fat accumulation outside of adipose tissue through various mechanisms can harm insulin sensitivity, thus impairing the regulation of blood glucose levels.

What can we do about it?

Weight loss can help reduce plasma free fatty acids, but there are other approaches to note. Getting an ample amount of uninterrupted sleep (e.g., at least 7 hours) may reduce plasma free fatty acid concentration. Further, in individuals with obstructive sleep apnea, seeking treatment may reduce plasma free fatty acids. For cigarette smokers, quitting may also reduce plasma free fatty acids. Ultimately, there are multiple factors that could be harnessed to reduce the free fatty acid level in the bloodstream, creating a metabolic environment in the body that may support improved blood glucose regulation.

Summary and conclusions

For people with obesity, it is common to have pre-diabetes or diabetes. One reason for the impairment in glucose metabolism is that the fat tissue is releasing free fatty acids at a rate that is much faster than the body’s energy needs. This excess fat transfer to other organs can ultimately impair glucose regulation. Thus, the fats in the blood can be considered as one of the major culprits for the worsening of blood glucose regulation that commonly occurs in obesity.