Abstract: Artificial sweeteners (ASs), high-intensity substitutes for sugar with minimal calories, are used extensively in foods. In recent years, their potential health risks to humans have gradually attracted more attention as consumption levels increase. This systematic review examines how different doses of artificial sweeteners affect the gastrointestinal tract, cardiovascular system, liver, and tumor development, along with their underlying mechanisms. Research indicates that common sweeteners like sucralose and aspartame generally increase the risks of colitis, atherosclerosis, fatty liver disease, and tumors by disrupting gut microbiota, raising intestinal permeability, and inducing chronic inflammation. Although individual artificial sweeteners may show minor protective effects within acceptable daily intake (ADI) limits or at specific doses, overall negative health effects tend to dominate. The review also highlights that current ADI standards, based only on short-term exposure assessments, significantly underestimate the cumulative and combined health risks from long-term, mixed exposures in real-world settings. Therefore, future efforts should incorporate multi-omics and systems toxicology approaches to develop a dynamic risk assessment system based on real-world exposure levels and population variability. This framework will provide scientific evidence for the safe use and regulation of artificial sweeteners.