I read the whole article on CNN. As expected, Limbaugh's description of the diet is seriously flawed.
For one thing, the guy didn't just eat Twinkies. He ate a can of vegetables, a protein shake and a multi-vitamin every day. Limbaugh doesn't mention those trivial
details in the transcript. The Twinkies provided the diet's caloric content. The nutrition came from other sources. So, referring to it as a "Twinkie diet" is disingenuous. Another point Limbaugh fails to mention: when you do the math, the guy only ate five individual Twinkie cakes a day. That's not exactly stuffing your face with Twinkies. Finally, though Twinkies have a reputation as being tiny cakes of death, they're really nothing more than 150 calories of flour, sugar, eggs, and lard (plus a bunch of flavor and texture additives with scary names, that are nonetheless ubiquitous in processed foods). The fat content is 4.5 grams, so eating five a day amouts to 22.5 grams of fat intake a day, significantly less than the 30 grams that constitute a low fat diet. And the cholesterol content? A mere 20 mg, or 7% of the RDA. Multiply that by 5 and you've got a grand total of 35% of your daily recommended cholesterol content. No wonder his cholesterol count improved!
Limbaugh, of course, mentions none of this. Instead he uses this diet to attack Michelle Obama, and reinforce his listener's desire to be told that everything those danged liberal authority figures have told them up to now is false, and the way to really lose weight is to stuff yourself with Twinkies, Doritos and Cheese Puffs.