We report on an analysis of the gas and dust budget in the the interstellar medium ( ISM ) of the Large Magellanic Cloud ( LMC ) .
Recent observations from the Spitzer Space Telescope enable us to study the mid-infrared dust excess of asymptotic giant branch ( AGB ) stars in the LMC .
This is the first time we can quantitatively assess the gas and dust input from AGB stars over a complete galaxy , fully based on observations .
The integrated mass-loss rate over all intermediate and high mass-loss rate carbon-rich AGB candidates in the LMC is 8.5 \times 10 ^ { -3 } M _ { \odot } yr ^ { -1 } , up to 2.1 \times 10 ^ { -2 } M _ { \odot } yr ^ { -1 } .
This number could be increased up to 2.7 \times 10 ^ { -2 } M _ { \odot } yr ^ { -1 } if oxygen-rich stars are included .
This is overall consistent with theoretical expectations , considering the star formation rate when these low- and intermediate-mass stars where formed , and the initial mass functions .

AGB stars are one of the most important gas sources in the LMC , with supernovae ( SNe ) , which produces about 2–4 \times 10 ^ { -2 } M _ { \odot } yr ^ { -1 } .
At the moment , the star formation rate exceeds the gas feedback from AGB stars and SNe in the LMC , and the current star formation depends on gas already present in the ISM .
This suggests that as the gas in the ISM is exhausted , the star formation rate will eventually decline in the LMC , unless gas is supplied externally .

Our estimates suggest ‘ a missing dust-mass problem ’ in the LMC , which is similarly found in high-z galaxies : the accumulated dust mass from AGB stars and possibly SNe over the dust life time ( 400–800 Myrs ) is significant less than the dust mass in the ISM .
Another dust source is required , possibly related to star-forming regions .