US News and World Reports published a ranking of diets based on input from a panel of diet, nutrition, and health experts. The rankings and methodology can be found here: https://health.usnews.com/best-diet/best-diets-overall.
There are a combination of general diets such as “Mediterranean” and “Asian”, as well as for profit diet programs such as “NOOM” and the “Ornish Diet”. Like any ranking system, the rankings depend on the criteria and the ranking panel.
The criteria that was used is listed below:
How easy it is to follow.
Its ability to produce short-term weight loss.
Its ability to produce long-term weight loss.
Its nutritional completeness.
Its safety.
Its potential for preventing and managing diabetes.
Its potential for preventing and managing heart disease.
Interestingly, the Vegan diet is rated number 17 and the cons were: 1) “The diet can be complicated/difficult to follow” and 2) “Some nutrients can be lacking”. Those 2 categories, especially the difficult to follow gave an advantage to the “programs”, like Jenny Craig or NOOM, that hold your hand all the way, were cited for several diet types. The nutrients lacking in a vegan diet are known and, arguably, can be compensated for with a few supplements.
The analysis didn’t highlight a few important factors in any diet, such as locally sourced (meaning not factory raised) ingredients, a variety of foods to get the widest spectrum of nutrients, and minimally processed ingredients.
I think it is worth reading a variety sources of information, even if your favorite is not at the top of their list, so read the report for yourself.