[1] shows that artificial sweeteners lead to higher insulin resistance. It is so because they provoke insulin level increase due to their sweet taste.
Caffeine is a tricky one.
If you can drink 6 cups of espresso a day, you have 50% less chance developing dementia. But, how can you drink 6 cups of coffee per day if you do not have good health? It can be that the "small positive effects of caffeine" are due to caffeine consumers have a little better health overall and these with worse health have to consume less caffeine.
For an anecdote, I once went completely off caffeine for a month and haven't noticed a thing after first three days, when I was unusually sleepy. Even training results followed the same progression.
[1] shows that artificial sweeteners lead to higher insulin resistance. It is so because they provoke insulin level increase due to their sweet taste.
Caffeine is a tricky one.
If you can drink 6 cups of espresso a day, you have 50% less chance developing dementia. But, how can you drink 6 cups of coffee per day if you do not have good health? It can be that the "small positive effects of caffeine" are due to caffeine consumers have a little better health overall and these with worse health have to consume less caffeine.
For an anecdote, I once went completely off caffeine for a month and haven't noticed a thing after first three days, when I was unusually sleepy. Even training results followed the same progression.