But while stars have access to teams of doctors, dietitians and trainers, regular people mostly manage their food intake alone. And that, say experts, is where public examples like Swank can be deceptive.
"Their bodies are their full-time job," Sharon Akabas, the associate director of the Institute for Human Nutrition at Columbia University, said of celebrities like Swank and Simpson. "Most people don't have that time, and then what they end up doing is taking different pieces of the regimen in the hope that they can achieve what she has."
"What these people really sell is hope," Akabas continued. "They hook people in that they'll lose weight. — But almost no one can maintain these regimens."
Rudd Center's Schwartz agreed.
"There are patients with eating disorders who aren't eating enough and then take vitamins to make themselves feel like they aren't putting themselves in danger," Schwartz said. "My biggest concern with this story is that if Hilary Swank is doing this … it may give some young women the impression that they don't have to eat a balanced and adequate diet."
But Garcia, who emphasized that Swank's supplements are just that — a supplement to an already-balanced diet — said such concerns were misplaced.
"From my perspective it's interesting that people don't question the fact that many stars have really bad practices," he said. "They eat tons of fast food, they smoke, they drink — and no one comes out and says, 'whoa, what's that all about?'"
He added, "What we're interested in is just a really good state of health."
As for Swank, it seems her pills pose a potential health hazard, though not in the way one might expect.
"I shoved them right in my mouth right before I met you, which I actually shouldn't do," Swank told W Magazine of her favored Longevity Pak. "Because I choked on my vitamins once before."