[Avodah] aveilus of Nine Days is equivalent to Shloshim

[SBA]

From: "Moshe Feldman" 
>> The aveilus of Nine Days is equivalent to Shloshim.  <snip>   RMS is
quoted as saying: if someone wishes to be machmir on himself and not wash on
Erev Tisha B'Av, "m'heicha teisi." <<

Doron Beckerman> I've always wondered about the equivalence of  the Nine
Days to Shloshim -
============
Nefesh HaRav p. 191 cites Pischei Tshuva OC 551:3 citing Tshuvas Panim
Me'iros that a woman is permitted to have a haircut during the Nine
Days given that there are *some* poskim who permit her to have a
haircut during Shloshim.  The implication is that the Nine Days are no
more chamur than Shloshim.
>>

What about eating meat? Who bans eat during Shloshim - or even Shiva?

SBA