In the United States, artificial sweeteners such as aspartame are regulated by the Food and Drug Administration (FDA). These products must be tested for safety and approved by the FDA before they can be used. The FDA also sets an acceptable daily intake (ADI) for each sweetener, which is the maximum amount considered safe to consume each day during a person's lifetime. The ADI is set to be about 100 times less than the smallest amount that might cause health concerns, based on studies done in lab animals.
The FDA has set the ADI for aspartame at 50 milligrams per kilogram (mg/kg) of body weight. The European Food Safety Authority (EFSA), which regulates food additives in the European Union, recommends a slightly lower ADI for aspartame, at 40 mg/kg.
To put the ADI for aspartame in perspective, this would be 3,750 milligrams per day for a typical adult weighing 75 kilograms (about 165 pounds), far more than most adults take in daily. A 12 ounce can of diet soda usually contains about 192 milligrams of aspartame and a packet of the tabletop sweetener