As a Registered Dietitian, I live and breath nutrition and appreciate people that do the same. The individuals listed below are who I'd consider "the good guys" of the nutrition blogosphere. You see anybody can be a nutrition expert on the Internet, but these guys truly are and back it up with studies proving their claims. There are no doubt many more but these are my favorites. Here's a quick breakdown:
Alan has a funny and saracastic writing style and his articles toe the line between layperson and medical expert, which keeps them right in the sweetspot of readability. He's coined such terms as "Broscience" which is a fun dig at the bodybuilder types who make up the nutrition as they go (eg "don't eat fat and carbs together bro, it will cause an insulin spike and drive all that fat right into your cells!)
Make no mistake though, he is an expert.
My favorite Aragon article would be his rebuttal of Dr. Lustig, appropriately titled "The Bitter Truth About Fructose Alarmism"
-funny, engaging writing style but still plenty meaty enough for the clinician
-great t-shirt shopping for those of us that want to take our love of nutrition one step further
-outstanding free articles on various sports nutrition topics
-Alan specializes in interpreting the most current research and relaying it for the non-epdemiologist in all of us
-not updated as much recently, but it's a free site and he turned down a full time job with The LA Kings professional hockey team so you know his private practice is booming!
James has a more serious style than Alan and sometimes likes to play logician or debate team captain a bit too much but his articles are excellent. His series on insulin blew my mind. If you think you know about insulin, insulin resistance, etc.. I highly suggest you read his series on it. Read the WHOLE series, it's free and it's worth it!
James has switched his website, weightology.net over to a pay version so I no longer frequent it but he has a great series of free articles available.
-This guy used to run the BS detective blog. IMO, he specializes in breaking down junk science, no matter how high up it comes from and he always backs his claims with studies that are hyperlinked within his articles.
-Like Alan, he makes professional reading, more readable
-The debate/logic jargon gets a bit tiresome but usually that's because his readers antagonize him.
-It's a pay site now. I'm sure it's well worth it but my Glock 19 is entirely too hungry to be spending my dough on this.
Dr. Stephen Guyenet
This guy is incredibly smart and I have no problem admitting I have to read some of his articles multiple times before I really get it but the information is golden. He's probably the most anti-dietitian of the three which seems to mostly stem from his disdain for Ancel Keys, the high carb, low fat diet that followed and is still being followed, and IMO, a false sense that we as dietitians are anti-fat. To clarify; it seems like he wants to dismiss us as not knowing the differences between fats and we would likely dismiss him because he's not an RD. The shame of it is, we could both learn so much from one another.
This is one of my favorites from his site. It's an article on oxidized LDL.
-Detailed, clinician-level articles that address hot topics in nutrition
-Articles that explain mechanisms and provide reasoning for why the lipid hypothesis is bunk (if you choose to believe that way)
-Dr. Guyenet just does a wonderful job of explaining the physiology of various studies. Anyone can read and site studies to back of their claims but Dr. Guyenet's blog is a fantastic resource for learning the how's and why's.
-Appears to be somewhat anti-dietitian. This seems to mostly be from the fact that we educate on AHA Step I type diets/paint saturated fat as the bad guy
-He states that randomized controlled studies are the only type that show that saturated fat increases cholesterol. In otherwords, he's saying that we can't show that with longterm studies. IMO, he's grasping at straws here because RCT with humans are the gold standard and by implying otherwise he's lowering his credibility. However, he's the PhD so maybe he knows something I don't.