I liked the experimental method, two weeks on one diet the two weeks on the other without restricting food intake.
I've been doing some dieting of late and made the facetious conclusion that if you limit your diet choices to only foods you don't particularly like to eat, you lose weight :-). But the converse of people working very hard to make their food really tasty (generally by adding sugar and salt according to the paper) people consume more than they need.
I'm not sure what we could do about it though, we can encourage better eating choices but there is a limit on how much that works.