From the article in post one about the same rankings:
"The top three diets for weight loss are the Weight Watchers Diet, the Biggest Loser Diet and the Jenny Craig Diet, according to the rankings. "The data show that dieters had the best luck with Weight Watchers for both short and long term weight loss," and the diet ranked highly in terms of how easy it was to follow, Enos said. "The Weight Watchers plan is also the diet that people most often return to — it appears in the article (and in my own experience) to be the diet that people really refer back to over their lifetime." The experts rated the Weight Watchers diet as a 3.7 out of 5 in the category of easy to follow, whereas the Biggest Loser diet scored a 2.9 in this category, according to the rankings. The Jenny Craig scored a 3.6, but fared less well than Weight Watchers in terms of its ability to produce weight loss."
So why did the other three diets (DASH, TLC and Mayo) rate higher? The focus on overall healthy eating (lowered cholesterol and salt, etc) was looked at as well as simple weight loss.
The Top 10 diets overall according to US News and World Report (looking at Weight Loss, cholesterol, salt, etc):
# 1 DASH Diet (4.1 out of 5.0)
#2 TLC Diet (4.0 out of 5.0)
#3 TIE Mayo Clinic Diet (3.9 out of 5.0)
Mediterranean Diet (3.9 out of 5.0)
Weight Watchers Diet (3.9 out of 5.0)
#6 Volumetrics Diet (3.8 out of 5.0)
#7 Jenny Craig Diet (3.7 out of 5.0)
#8 TIE Biggest Loser Diet (3.6 out of 5.0)
Ornish Diet (3.6 out of 5.0)
#10 Vegetarian Diet (3.5 out of 5.0)
The final conclusion? Probably any of the following will be good picks for most people: DASH, Mayo, TLC, Weight Watchers, Jenny Craig and Biggest Loser. Certain ones may have advantages for certain people.