verbs - Correct usage of "consists of"

I found a confusing usage of "consist of" in Belles Make Up site:

• Water consists of 70% of our whole body.

I think that above sentence is wrong because water is within our body, not the body in water; therefore, it should have been like this:

Additionally, how and when to use "made up of"?

Answer

Your suspicion is correct. I've checked the following dictionaries:
American Heritage Dictionary
Oxford Living Dictionaries
Collins Dictionary
Merriam-Webster Dictionary
Random House Unabridged
Random House Kernerman Webster's College Dictionary

And not one of them attests to your first quotation example being correct, but instead your second one as being correct.

Generally the definition is something like:

1. To be made up or composed: New York City consists of five boroughs.
   American Heritage Dictionary

However, note that inversions of this kind tend to naturally drift among people and time periods. For example this is the usage note from American Heritage Dictionary for the word "comprise":

Usage Note: The traditional rule states that the whole comprises the
parts and the parts compose the whole. In strict usage: The Union

comprises 50 states. Fifty states compose (or make up) the Union. Even
though many writers maintain this distinction, comprise is often used
in place of compose, especially in the passive: The Union is comprised
of 50 states. Our surveys show that opposition to this usage has
abated but has not disappeared. In the 1960s, 53 percent of the Usage
Panel found this usage unacceptable; by 1996, the proportion objecting
had declined to 35 percent; and by 2011, it had fallen a bit more, to
32 percent.
Free Dictionary

This note is a good example of how the acceptability of word usage changes over time, and I'm not sure if "consist" is undergoing the same sort of drift.

Another and even more contentious example is "substitute" where strictly speaking the "substitute" is the replacement supposed to take the place of the thing removed, however it's extremely common for it to be used the other way around. The dictionary usage panel generally disapproves of the 'incorrect' use. However the panel is more accepting of its use in a sports context, where it's very common for one player to be substituted by another. The thing is that language naturally evolves whether we like it or not.

If you're interested in the "substitute" controversy, here is the link to the usage note.
Substitute