"More than 80% of people who drank water even once in their lifetime have died!" is a true statement of fact (if you follow the accepted estimate of ~100 billion humans ever). Does it communicate something incorrect? That very much depends on the reader.
Truth vs. Lie, especially by omission, is so context dependent that there's no objective measure one can use.
Truth in this context is not well defined.
"Dietary cholesterol increase associated with increased mortality" and "Dietary cholesterol increase not associated with increased mortality" are, in fact, both true depending on context. A well written and researched article may elucidate the context in which the headline is true, or (as is more often the case) will just assume that context.
Is it fake news? Depends on the reader's context, but for 99% of the readers at least one of them is fake news, because they are not familiar with the context in which the other is true.
In my experience, the things reported where people -- if they actually looked at the evidence -- would have consensus about "true" or "fake" are actually a small fraction of the things which are - in widely accepted contexts - false.
Let's say I publish an article saying "oxycontin is addictive even if used as prescribed" - today it is considered true, five years ago it was considered fake. The facts did not change, and quite a few people claimed that was the case and had facts to back them up five years ago. This one is easy to talk about because it's essentially been "resolved". There are thousands of examples that have not been resolved, and depend on your context and sources about whether they are "fake" or "not fake".
The whole point of lying by omission is that the statement is true -- even when what is communicated isn't.