Hadley v. Kellogg’s, pending in Northern California federal court.
I skimmed the 109+ page complaint. It’s beautifully written and if you told me that Gary Taubes or Nina Teichholz were standing over the lawyers’ shoulders and hovering over the keyboard as they typed it, I’d believe you. 
It’s really a brilliant piece of writing, including color pictures of the cereals and products at issue (e.g., Nutri-Grain bars).
The gist of the complaint is that Kellogg’s added sugar to cereals but continued to claim they were heart-healthy and nutritious.
The overriding theme of the complaint is that sugar is toxic and terrible for us, and Kellogg’s knew or should have known this (and either warned us or not lauded the products as healthy).
The Court recently denied Kellogg’s motion to dismiss the complaint. The Judge found that the class action complaint contains plausible claims that should be allowed to proceed to trial.
I think this case might have some legs, and won’t suffer the quick defeat like the soda lawsuits saw. Here, you have an allegation that the manufacturer is marketing the product as “healthy” when it’s allegedly not, whereas in the soda lawsuits, no such claim of “healthiness” was made.
I recommend following this one. It’ll be interesting to see how it shakes out. Understandably, one of Kellogg’s main defenses is the Nutrition Facts (“The sugar content is right there - everyone can make their own assessment on whether to consume this or not.”) (By the way, this strikes me as a very formidable defense that the class will have to overcome.)
We will see if the plaintiff is in it for the long haul and not a class action settlement for Raisin Bran coupons! 
Based upon how the complaint reads, he and his lawyers appear to be the real deal and in this for the right reasons. Time will tell.