I've uploaded six powerpoint slides from Dr. Kelly's presentation (with his kind permission).
They're available for download here, from the Files page of this Meetup site.

The idea here is that the view of plant-based diet has shifted over time:

-a plant-based diet used to be viewed as a diet that carried significant additional risk of nutritional deficiencies, in contrast with animal-based diets that were thought to be a more optimal dietary pattern.

-this thinking has shifted, so that today plant-based diets are still perceived as carrying additional risk of deficiency, but now animal-based diets are also perceived as having similar risks but of "nutritional excess." In other words, people eating a plant-based diet need to "be careful" no more, no less than people eating an animal-based diet.

-the third slide shows a more accurate model depicting the fact that the risk of excess with an animal-based diet is greater than the risk of deficiency with a plant-based diet, thereby putting a greater proportion of animal-based-diet-eaters at health risk than plant-based-diet-eaters.

-the fourth slide shows a proposed hypothesis of dietary adequacy: not only has the risk of excess been understated until now, but the risk of deficiency has been overstated. As evidence mounts of the protective characteristics of plant-based diet, it will come to be viewed as typifying the optimal diet, whereas "you will need to be more careful" if you eat an animal-based diet.

You can read the original article by Joan Sabaté here:
http://tinyurl.com/5a...

(The citation on the slides should actually read: Joan Sabaté,
The contribution of vegetarian diets to health and disease: a paradigm shift?
Am. J. Clinical Nutrition, Sep 2003; 78: 502S - 507S. )