Facebook causing depression when used too much? What were the alternative groups doing? Correlation is a tricky thing to measure. I'm not sure how I feel about these types of studies or what utility they really provide.

Other than maybe giving the reader some perspective on their life. Anything used in a poor context, for example not combined with the right attitude, environment, etc can cause issues.

Often we just fall into negative cycles and need to be kicked in the butt to change them. We often fixate on one specific thing, like I quit smoking and suddenly became healthy (but I also worked out, started eating better, spent less time/money on a neutral/negative activity, etc, etc). There are always so many moving parts.

At most you could critique Solyent if they advertised as the solution to your health problems. Rather than something to replace 1-2 daily meals when you're on a tight schedule. The former is a complicated multi-faceted lifestyle thing that no company could offer with a single product but that won't stop them from positioning the product that way. But we should be smart enough to know it will only ever (potentially) be a component of it.