Can an American live in Guadalajara,Mexico for $400 a month for food and rent?

Yes if you like to be at the corner begging for money.
Of course not. What kind of city you americans think Guadalajara is? Guadalajara is as modern as any other city in the States, and expensive. You will need at least 1,500.00 usd monthly to live decently here.

yes you can i live in guadalara and many people make less than that! $100.00 american dollers is right about $1000.00 pasos.It can be done you will not be able to live like you can in america but you will not starve to death Report It

It can be done, you would be cutting it close eating out of the mkt. fruit bakery rolls. I don't know how long you could last. I stayed for a month in Pt. Escondido in a hut on the beach rent food everything for $400.00 5 years ago. If you take a crock pot you can live cheeper. I know a man living in Oaxaca for less than that, but he has been doing it for years knows in and outs.

Too tight!

Live in a student room and buy food in market

The answer is YES. You will be not eating out living in a cheap dumpy place but yes it can be done if you expect much.

Maybe if you rented a room in a poorer neighborhood and ate what poor Mexicans eat. Many Mexicans live on less than $300US a month.
It gets pretty cold in the winter and there's no heating in even expensive houses and apartments.
You might try to find someone to share with.

Why would you want to? Anyone, American of other, can live anywhere for 400USD a month. It depends on how much privation you wish to endure. Retirees squeak by on 1,200 a month in Mexico with a little help from family. If you are talking about a social cultural experience, its possible to find a family who will take you in.

No chance. Simple as that.