No idea why it would be 5 years. But a lockdown would not result in starvation. Why would it? We "only" lock down social life (bad enough with all kinds of negative impacts on people, society and economy), but the food supply won't brake down. Why would it? All necessary things will be kept open.
Worldwide, that's not to be taken for granted. Here in Russia, the police is sometimes stopping agricultural workers from planting their crops because of the lockdowns. (Source in Russian: https://www.kommersant.ru/doc/4311038)
I think the point was not that food distribution would fail, but that the more disadvantaged slice of the population would not have money to buy food anymore.
