If a restaurant is turning a profit then people will invest in it, regardless of how crappy the food might be. Why else would McDonald's have a market cap of 98 billion. Remember for investors and venture capitalists it is all about the bottom line.
It takes more than a good idea to get investors. You need to have a demonstrated revenue stream and skin in the game. Have you ever sought investment capital for a business venture? I have and I know that it is extremely difficult to get money unless you already have something in place. Investors do not invest in ideas, they invest in businesses. What he has is an idea, it may be a good one, but he needs to invest his own money to prove it is a viable commodity before he can expect others to partner with him. Unless of course they are family or friends that will take a stake in him - but people from the outside are not going to invest in an idea.
I have friend in the business. He and his wife started out young, in their early 20's. They were both in the industry for a few years when they decided to open their own place. To get the money, he tended bar and she waited tables about 80 hours per week. They lived in a one bedroom apartment, they had one car between the two of them - they denied themselves every luxury most of us take for granted. They saved up enough cash over a few years (about 200K) and started a small place, they built it up over the years and now (about 15 years later) they never have to work another day for the rest of their lives. In fact they started a second restaurant about 5 years ago, built that one up and sold it for 2.5 mil. They still have their first place.
But there is a difference between them and what the OP has talked about - they worked their asses off, 2 jobs a piece for years to get to where they are. The OP has not expressed that level of commitment in his posts.
There is a huge market available for someone who wants to sell real food. Take it from the perspective of someone who only eats healthy foods, there are hardly any restaurants you can go to that sell you healthy foods. I would like to eat out more, but there is not much available.
I've sought capital before, and you are right that many investors want you to have an established business and want you to have exhausted all your money and your friends and family's money. But what really sells investors is having one simple compelling concept that is capable of making a ton of money. Anyone who has tried to eat healthy knows there is a huge gaping hole in the restaurant/health food industry. I am confident that if I wanted to, I could sell this concept to investors. The bigger issue is is this guy going to do everything that is necessary to make that business successful. I don't know that answer. I don't know him. But thats something he would have to demonstrate to get money.