The bottom line: "Choosing a diet partner, like choosing a diet, is a very personal matter," says Schwarz. Just as there is no one diet that's perfect for every person, Schwarz tells WebMD, there is no one type of diet buddy that is universally better than another.
Shafran agrees, "The truth is that even if we share the same goals, what it takes to get us there is different for every person. And that means every person needs something slightly different in a diet buddy."
So how do you figure out what you need? Look deep inside yourself and be brutally honest about what you need to get your weight loss mojo working, Dweck says.
Don't just focus on doing things together, Shafran says.
"Diet buddies are just two people who share a common goal and know they can count on each other to help them achieve that goal in whatever way it takes to do that," says Shafran.
For some, that may mean working out together or getting together to cook or swap recipes a couple times a week. For others, it can mean taking turns babysitting so that each of you can get to the gym separately.
Another consideration is mutual availability. Both partners should agree up front on how much time and energy they have to devote to the partnership, and discuss what they need from each other during that time.
Also important: The primary mode of contact and support. If you're constantly monitoring your email and need a buddy who's always there when you send out that Instant Message S.O.S., be sure you pick a buddy who is as computer-accessible as you. If what you really need is face-to-face contact, pick a buddy who has a similar need -- and the time to share.
"For some people, the anonymity of having an Internet buddy is the best solution. For others, it has to be someone who they can get together with for a Wednesday night weigh-in," says Shafran. "It doesn't matter, as long as both buddies want the same thing."
No matter what your mode of communication, it's important that buddies spend time listening to each other.
"It can be online in a chat; it can be on the phone; it can be in an email; or it can be in person, as long as there is some time that each of you can devote to listening and encouraging the other," says Dweck.
It's also important to recognize that encouragement comes in many different forms.
"For some people, it means hearing kind and supportive words; for others, it means having someone come by and literally drag them out of the house and to the gym," Dweck says. "As long as both buddies know what the other needs and expects, then they can be there for each other."