First of all, let us establish the fact that a day without food cannot kill you, after all people fast for 40days and 40 nights and even when Satan tempted Jesus with bread after he has not eaten for over a month he did not fall, instead he responded man shall not live by bread alone... But let us recount what a day without phone can do to us;
You can loose a business deal.
You can loose your job on counts of negligence.
You can die from not getting access to life saving or privilege information.
You can fall victim to avoidable circumstances that a phone call or text message could have prevented.
Imagine travelling long distance to see someone that is not in and won't be back anytime soon, a phone call would have prevented such unnecessary expenses. In this internet era, I don't think there's anyone whose not mobile. even those women that trade in bush markets, the illiterates, they all use mobile phones. It could be the phones without internet connection but they are still mobile and they can communicate with their customers through phone calls.
If you are the type of person that renders services and you are a hot cake in your field, you can not risk you phone battery draining. Hence powerbanks are fast selling as that is the only portable thing that can be carried around to boost our phones.
Just few days without network some of us can attest how boring our life turned out, for those who can't handle their emotions, I bet they lost interest and appetite in food as we've all succeeded in building our lives around our social media profiles. Thus, the phone becomes useless when it cannot be utilized for connective purposes.
It is also worthy to note that it is from the usage of phone that a lot of people get money to even purchase food items. There are people and companies who will loose millions if their phone run down or becomes unreachable. Imagine after being unemployed for years and you finally get a call to come for an interview but that is the day your number becomes unreachable as your phone was maybe stolen or your battery has ran down. Imagine loosing a lifetime opportunity or causing your company to loose millions because you are not mobile.
A friend of mine spent some reasonable amount of days in cell because the money he kept in his office was stolen. How did it happen?
They were done with sales but before he finished reconciling the account, it was already late and the account department was closed so he left the money in the office and went home. He got home, showered, ate dinner and slept off as he was exhausted.
He woke up at past 10pm and saw that his supervisor had called him an hour earlier, he returned the call but no response. The next morning he got a call that his office was burgled. He rushed down and saw that all the money that his 15years salary cannot pay was gone. When investigation started the Supervisor in his defense said he had called him to make sure the money gets to account but my friend busied his call. Oga supervisor lied.
My friend in his defense said he had sent my supervisor a message on what to do with the money but the supervisor never responded.
Supervisor claimed to not have seen the message lol. That was how my friend entered cell for two weeks.
In summary, I don't think a day without food will kill anyone not even a foodie but then a day without phone can cause irreversible damages.