How can nutritional science be made more accurate?

[sanantone]

On the subject of diet. There is a lot of studies. But there is no pictures of the before and after of a person to sustain those studies.
(I am not taking about the marketing campaigns promoting diet). I just would like to see plain before and after pictures with real
people for every proposed diet. And then a follow up. Why it is so hard ? Maybe they all know that their proposition do not pass
a reality test.

Scientific studies don't display pictures of participants. That would be considered unethical. An IRB would never approve that. Plus, these people are often considered patients, so their healthcare information is confidential under HIPAA.

---

Maybe independent studies with people that allow their personal information to be released (Open Source Style).

That's entering dangerous territory. An independent group of people should always review research proposals involving human test subjects. Before internal review boards, there were a lot of unethical studies in medicine and psychology that caused harm to the subjects. Besides, most people are fine with just reading the data.