Nutritional Update for Physicians: Plant-Based Diets
This article contains a pretty good discussion of the differences between a whole foods plant-based diet (health-promoting) and vegan or vegetarian diets (not necessarily health-promoting). The whole foods plant-based diet is defined by what it includes (whole plant foods, emphasizing vegetables, fruits, nuts, and seeds, plus B12 and sun exposure), whereas vegan diets are defined by what they exclude (animal products) with no restrictions on what they include within the plant realm and no specific attention to nutritional adequacy. Thus a vegan diet can include refined oils, hydrogenated oils, large amounts of saturated fats (tropical), refined carbohydrates, and so on, and the vegan does not necessarily eat recommended levels of fruits, vegetables, nuts, or seeds, get sun exposure, take vitamin B12, have a reasonable essential fatty acid balance, or pay any attention to getting adequate intakes of energy or other essential nutrients. The incorrect conflation of these two can lead one to confuse their health effects.
While many vegans do eat whole foods plant-based diets to some extent, not all do, and the inclusion of the latter in data sets defined by exclusion (no animal products) can confound results of research. Keeping this in mind, it remains remarkable that, as reviewed in this article, a significant number of studies have provided evidence that people eating vegan or plant-based diets have significantly reduced risks of obesity, diabetes, cardiovascular disease, hypertension, and overall mortality.
The article also leads off with a case study of an individual prescribed a plant-based diet, with a report of the positive health effects.