Cant live on potatoes alone, you need protein so he needs to bring a few cows and some chickens to space. For that you need grass, water and oxygen.
Going to space and living on mars is a pipe dream that wont be realized for at least 200-300 years into the future. Its only a sales pitch, the real reason they want to go to Mars is to send robots to mine precious metals and minerals. But even that is still 50 years into the future, in the interim they just selling a dream.