As an RD myself (MPH, RDN actually) I have found that the profession, as a whole, is populated with individuals that love food, like helping people, and are interested in "diets" up to a point. There is so much I agree with TA concerning guilt over food choices (reaks havoc on hormones) and the wrong emphasis on monomacros (limiting any macro is a mistake).
But, there is a problem with the premise of the question. The problem assumes the person eating fast food doesn't overeat or commit other dietary abuses concerning sugar, salt, and fat, this versus an organic diet that has organic chips, cookies, grain-based desserts, and commits the aforementioned abuses. Looking at epi-studies, the majority of health benefits come about due to weight loss, not macro makeup, mononutrient emphassis, or new "Superfood" inclusion.
Lastly, one major problem with TA 's argument has nothing to do with his argument, it is that he has a really good physique, so some credence is lent to his position. He has control over his behavior which is the main problem with how all diets fail or work. Behavior change! TA, I have been assuming, can put the fork down after 10 bites and the majority of people will go to bite 20.
D