You can read Gary Taubes stuff. He is a science writer, who was sucked into the diet controversies about 10 years ago. Books and articles in NY Times Magazine, among others. http://www.garytaubes.com/
Look for these articles in NYTimes Magazine:
There are online videos linked from his site.
This video is from an appearance in 2011 in
(Search youtube for "Gary Taubes Walnut Creek")
For Sugar, there is also the Robert Lustig: "Sugar, the bitter truth" (search for it on Youtube -- 90 minutes.
A 90-minute discussion of the nuances of fructose biochemistry and human physiology. He does not like Coca-cola.
Lustig is a specialist on pediatric hormone disorders and the leading expert in childhood obesity at the University of California, San Francisco, School of Medicine
Warning: After viewing this, you probably won't be drinking gatorate, soda, or fruit juice.
Started as a cardiologist, and moved into dieting and nutrition when he found out about low carbohydrate diets (he was far from the first), and set up a clinic in NYC, along with a radio show in the 70s. He passed away some time ago, but his name lives on. I find his books "Atkins Diet Revolution", for one fairly interesting. Read Gary Taubes to find out why this is not in the mainstream.