What's very inspiring are the body transformations posted by members of forums. Just check out the ridiculous before-and-after shots on the following thread from the SomethingAwful Forums' fitness subforum:

http://forums.somethingawful.com/showthread.php?threadid=333...

Threads like these are what inspire people to radically change their lifestyle, start lifting weights, and stay motivated. They go on to keep fitness logs to keep themselves publicly accountable, and also join Fitocracy and weight/diet-tracker sites. There're also a lot of helpful resource threads on such forums, informing newbies on diet, exercises, supplements, etc.

On the scientific side of things, I've spent the last few weeks reading a range of PubMed(Central) articles and various blogs and forums on fitness and diet. There are many schools of thought, but many are mostly supported by anecdotal evidence and not studies.

What I've found most helpful are scientific studies/articles, e.g.

- Evidence-based resistance training recommendations
http://baye.com/wp-content/uploads/2011/09/ebrtr-Fisher1.pdf

- ISSN recommendations for supplementation
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2853497/?tool=pu...

- Protein per day for muscle-building: 1.6 g/kg of bodyweight (not the 1+g/lb that many sites tout)
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2129150/

- Reduce saturated fat intake and replace with polyunsaturated fats, not carbs or monounsaturated fats
http://www.ncbi.nlm.nih.gov/pubmed/19211817

Scientific bloggers are also good to read, if they assess studies critically - people like Bill Shrapnel, DH Kiefer, Bryan Chung, Stephan Guyenet, Alan Aragon. Check their blogs out if you aren't already following them.

My current understanding of various controversial topics, based (mostly) on studies:

Calories in, calories out - absolute calories matters, but is mediated by the effect of composition of diet. Consuming more protein tends to result in an increased lean-mass-to-fat ratio (whether due to satiety, hormonal effects, or a combination of the two).

Carbs/sugars/starches - high glycaemic-index carbs are riskier than saturated fats for heart disease. They are also associated with weight gain. The endless intake of rice in Asian countries (like mine) makes many of us fat and at risk of heart disease.

Dietary cholesterol - probably not as bad as previously assumed, but having >6 eggs a week actually increases your risk of heart disease/events.

Intermittent fasting - I haven't seen the scientific evidence for this, though a friend assures me it's out there. All I see is Berkhan's leangains.com and I'm not sure I'm convinced. I searched PubMed for a bit but didn't come across anything.

Diet vs exercise for weight loss - diet is the key to weight loss. Neither cardio (whether HIIT or low-intensity) nor resistance training alone is particularly effective at causing weight loss (claims of raised metabolism notwithstanding); you need a calorie deficit as well.

Training to muscular failure - training to failure actually provides more efficient strength gains.

Genetics and muscle - genes play a major, possibly the largest, role in determining how much muscle mass individuals can gain and how easily they do it. "...it appears that those who are naturally lean and muscular to start with, can gain strength and size to a much greater degree than naturally ‘skinny’ individuals." i.e. ectomorphs won't be exploding with muscle in short order, despite their best efforts.