[adrian_b]

In principle, it seems impossible for any artificial sweetener to be completely safe, unless it is consumed only sporadically, not regularly.

Unfortunately, the receptors for sweetness do not exist for the sole purpose of giving pleasure to the brain.

They are also used to signal to various organs to prepare for an influx of carbohydrates. When the signal is frequently present, but then the expected carbohydrates do not come, then this is likely to perturb some control functions of the body, like in the fable about the boy who cried wolf.

[arghwhat]

> it seems impossible for any artificial sweetener to be completely safe, unless it is consumed only sporadically, not regularly.

This also holds for non-artificial sweetener, or in fact any substance entering our body.

Disturbing a process expecting a large influx of carbohydrates vs. disturbing the body with an actual high influx of carbohydrates, disturbing the body by neither consuming nor triggering carbohydrate processes, ...

Drinking bitter fluids - say, coffee - trigger early toxicity warnings that prepare your body for emergency oral bowel evacuation, as "bitter" is the taste of various substances evolution associated with food poisoning. What other mechanisms might that trigger? That's a lot of "crying wolf" for many people.

[discreteevent]

> disturbing the body with an actual high influx of carbohydrates

Eating food in order to have energy to do things is not "disturbing". The parent was talking about telling your body many times a day that its going to get carbohydrates that it doesn't need (and is not going to receive in the case of sweeteners) is the problem.

[arghwhat]

> Eating food in order to have energy to do things is not "disturbing"

It most certainly is. It disrupts several processes, requires significant energy and resource expenditure, spikes various hormones that may or may not be able to develop intolerances. Significant impact to the gut, pancreas, brain (e.g., reward systems).

Not all of the effects are as high profile as full on diabetes, but its most certainly very disruptive.

Even the most healthy things are disruptive and stressful. Exercise is also incredibly disruptive, causing significant continuous injury and a panic-like reaction trying to keep your body from falling apart at the seams den eject your heart through the nearest chest opening.

Living is the act of balancing on a knife's edge with every force in nature trying to knock you over. You live not because of nature, but in spite of it.

[adrian_b]

That drinking something bitter prepares your body in any way, is interesting speculation, which may be true or not. I am not aware of any evidence in favor of this idea. It seems more likely that the only purpose of the bitter taste is to make you spit the food before swallowing it. The sour taste has the same purpose for most animals. Humans and their relatives are among the few who enjoy sour things, and even some bitter things.

On the other hand, for the sweet taste we know that receptors exist not only in the mouth, but also in the intestine, where also the starch from the food would be already digested into glucose or maltose, so it would be sensed as sweet, and where the sweetness receptors do not cause any conscious sensation, so they must have another purpose.

The role of the sweetness receptors from the intestine is not known yet, because short-term studies could not determine it. However, they must have some effects, though those might appear only after longer times of periodic stimulation.

[arghwhat]

> I am not aware of any evidence in favor of this idea. It seems more likely that the only purpose of the bitter taste is to make you spit the food before swallowing it.

That would not explain why the stomach delays opening in response to bitter in the mouth, similar to preparing for protein digestion on glutamate detection.

But of course, we don't exactly have a spec sheet to work with here, so all we can do is theorize on why a particular trait might have evolved...