Rebecca Harrington spent a year trying out more than a dozen celebrity eating plans, all in the name of science…er, comedy.

By Julie Mazziotta
Updated: January 30, 2017
Photos: Getty Images

Ever wondered if you could handle BeyoncÃ©â€™sÂ punishing workouts while maintaining her post-baby diet? What about sustaining yourself on Victoria Beckhamâ€™s regimented eating plan for a day?

Rebecca Harrington spent a year trying out these diets and 12 more celebrity eating plans, all in the name of scienceâ€¦er, comedy. Her new book, Iâ€™ll Have What Sheâ€™s Having: My Adventures in Celebrity Dieting ($11, covers everything from the delicious (Gwyneth Paltrowâ€™s â€œtruly spectacularâ€ fish tacos) to the gross (see: Greta Garboâ€™s celery loaf).

RELATED:Â 25 Shocking Celebrity Weight Changes

Harrington, 29, tells Health that she started testing celeb diets after stumbling upon William Howard Taftâ€™s â€œhorrible but funnyâ€ diet online. From there, she moved on to Elizabeth Taylorâ€™s eating plan and a writing project was born.

She tried to stick to each diet for 10 days. Each brought different, oftenÂ hilarious challenges, and had varying results:

She found BeyoncÃ©â€™s favorite plan to be the most effective for weight loss; she lost 10 pounds doing a combination ofÂ theÂ Master Cleanse diet (which Queen Bey reportedly endured to lose 20 pounds for a movie role back in 2006) followed by the protein-packed eating plan Mrs. CarterÂ followed after Blue Ivy was born.

Harrington says she gained weight while following Cameron Diazâ€™s regimen, but chalks it up to muscle gain from following the star's workout schedule.

RELATED: 22 Stars Who Don't Seem to Age

In following the eating plans of long-ago celebrities likeÂ Jackie Kennedy and Marilyn Monroe (which includes choking down two raw eggs whipped into warm milk for breakfast, then starving until a hot fudge sundae dinner) as well as present-day superstars like Madonna and Victoria Beckham (who once followed the Five Hands Diet, meaning she eats just five handfuls of food a day), Harrington was able to tease out a change of tides:

â€œIn the past, diet food was abundant but disgusting. Now, diet food has smaller portions but is better tasting. I donâ€™t know which is more humane," she says.

Regardless, Harrington wouldnâ€™t recommend these diets to anyone. â€œI think they are all sort of insane for different reasons,â€ she says. â€œFor some diets, the food is so disgusting you would not wish it on your worst enemy. For other diets, the food tastes good but is way too expensive. A woman canâ€™t win!â€

â€œIf anything, I think it makes you feel quite grateful to eat like a non-famous.â€ We'll second that!

RELATED: 14 Ways to Cut Portions Without Feeling Hungry