The aim of this thesis is to present the basic characteristics of the endogenous cannabinoid system, with emphasis on its role in the regulation of metabolic functions. In this context, the effects and risks of cannabis use on the development of obesity and diabetes will be emphasized. Although there are a number of risk factors for developing diabetes, obesity is one of the most important. Cannabis administration can cause the development of obesity by activating CB1 receptors in hunger / satiety control centers. CB1 receptors are also present on peripheral tissues and together with the CB2 receptor subtype participate in the maintenance of metabolic homeostasis. The negative effects are due to the activation of the CB1 receptor, while the agonist effect on the CB2 receptor has a protective effect. It has also been shown that in the background of numerous complications of diabetes, such as diabetic neuropathy, nephropathy, retinopathy and cardiomyopathy, the modulating action of endogenous cannabinoids is ordered. Stimulation of CB1 receptors by exogenous ligands such as THC, also increases the risk of metabolic changes when consuming marijuana, acutely and chronically. Acutely, cannabis induces the development of glucose intolerance, as well as food intake and energy storage. Its chronic use reduces food intake and increases body weight. All this speaks in favor of the complexity of the topic and the need for its extensive explanation. New knowledge will contribute to understanding the risks of acute and chronic cannabis use, and may direct and develop new drugs with effects on the cannabinoid system.