Jean Lassalle, 52, has lost 21kg (46lbs) since starting his protest and was admitted to hospital on Friday.
But he agreed to end the protest after Toyal told Interior Minister Nicolas Sarkozy it would not close its paint factory in Accous in the Pyrenees.
The firm employs about 150 people in Mr Lassalle's constituency.
It planned to open another factory 60km away and the MP feared the Accous site would close, despite the firm's insistence that it would not.
Like a sad clown. I'm not asking to win. I'm asking for good sense to triumph
After talks with Mr Sarkozy, Toyal agreed to continue investment in Accous before investing elsewhere.
150 Jobs. 150 jobs that weren't necessarily at risk. So basically the people that live in one part (of the same country) should benefit before anyone else. Brilliant!