This is a segment from a larger guide to sweeteners:
The biggest reason to avoid artificial sweeteners is not related to their potential toxicity, but is rather related to their purpose. The only reason to use a zero-calorie sweetener is to avoid... the excess calories one would ingest through the use of a real sugar, in an effort to reduce total daily caloric intake.
While this goal is achieved in the very short-term, all evidence suggests the use of artificial sweeteners perpetually leads to increased daily caloric intake.
Research shows that when we consume an artificial sweetener, it triggers the first food reward pathway (sensory) but not the second (postingestive). Because we only partially trigger the food reward pathway, we are left feeling unsatisfied with the neurological result of increased hunger, particularly for the sweet food our body thought it was going to receive.
Glucose, on the other hand, triggers both food-reward pathways and suppresses hunger signals in our hypothalamus.
The danger associated with partially triggering our food reward pathways goes even further. When the brain is habitually tricked, it changes its expectations to match the new information, which says that sometimes food is not as satisfying as our mouth thought it would be.
This leads to a diminished sense of reward from eating, which means it takes more food or drink to reach the same level of neurological satiety, or fullness. Furthermore, because the artificial sweeteners are so sweet, they influence our taste for food and we begin to crave sugar more than normal.
PS: This is why we count drinks containing artificial sweeteners as a Cheat. For those of you who were wondering!!