Sun energy effect on human physical requirement

Have recently read about a German Cancer researcher claiming to get all his energy from soaking in Sun light , something like photosynthesis of plant ., claim that he had not eated solid food in years.
There has been numerous claims in the past which where investigated , and not much scientific result have ever been published .
Does anyone ? have a scientific result or ongoing test at reliable facility .
I have alway felt that what ever food you consume and it effect on your body is more to your belief , rather than calorie or other cause . Any comment would be greatly appreciated

I am a swimmer, and I have always been taught to never lay down in the sun inbetween my races due to the fact that the sun seems to make you tired? Although early in the morning if I am to lay down in my family room where the sun hits I seem to feel energized for the day. I know its wierd but its what happens lol. The photosythesis idea seems to be a little farfetched. Maybe the sun could excite your cells and maybe make certian reactions happen quicker or more effectively ( I do not have much knowledge in biology this is purely guess). Sorry about the random begning but I hope you saw my point.

There has been numerous claims in the past which where investigated , and not much scientific result have ever been published .
Does anyone ? have a scientific result or ongoing test at reliable facility['quote]
I think you sort of answered your own question. Ther were investigations, and, not surprisingly, the claim that the sun can feed humans was found to be baseless. Anyone attempting it will die a slow death of starvation. The people that claim to do it, are, simply, frauds.