[6] In 2022, Jamil worked on two superhero projects: the animated film DC League of Super-Pets and the live-action television series She-Hulk: Attorney at Law.

[8] At nine, she was diagnosed with hypermobile Ehlers-Danlos syndrome, a genetic disorder affecting the connective tissue in the body,[9][non-primary source needed][10] and at 12 with coeliac disease.

She believes her eating disorder developed due to societal pressure, including magazine articles selling weight loss products.

[26][27] In January 2009, when the previous presenter, Alexa Chung, left the morning TV show Freshly Squeezed, Jamil succeeded her as co-host, alongside Nick Grimshaw.

[43] While working as a writer at 3 Arts, her agents told her that Michael Schur, who co-created Parks and Recreation, was looking for a British actress for an upcoming comedy series.

[47][48][49] In September 2016, the NBC fantasy comedy series The Good Place premiered, with Jamil as a regular cast member, playing Tahani Al-Jamil.

"[58] In April 2020, she debuted her podcast I Weigh with Jameela Jamil, which focuses on women's accomplishments, body positivity, activism and racial inclusivity.

[60] In June 2021, Jamil was cast as the supervillain Mary MacPherran / Titania in the Disney+ streaming series She-Hulk: Attorney at Law (2022), set in the Marvel Cinematic Universe.

[63] In March 2018, Jamil created an Instagram account called I Weigh,[64] inspired by a picture that she came across online of Kourtney, Kim and Khloé Kardashian with their half-sisters Kendall and Kylie Jenner, detailing each woman's weight.

[64] The account welcomes submissions of followers' non-edited or airbrushed selfies using the hashtag #iweigh, with text describing the things that they feel grateful for or proud of.

[68] Jamil created a petition on change.org titled "Stop celebrities promoting toxic diet products on social media", with a goal of reaching 150,000 signatures.

She called upon social media networks such as Facebook, Twitter, and Instagram to ban the practice, noting its dangerous effects on teenagers.

They are instead, flogged in glossy paid adverts by celebrities and influencers with no expertise or authority in nutrition/medicine/biology.Using social media, Jamil often criticises media industry standards and labels other female celebrities "double agents of the patriarchy" by promoting unhealthy body image, often invoking her own experience of having an eating disorder in her arguments.

In 2013, she criticised Rihanna in her column for Company magazine, blaming her for maintaining a relationship with her abuser for fame, smoking marijuana, and posting "provocative images on Instagram to millions of hungry followers".

[70] In 2014, she voiced her disapproval of Beyoncé sexualising her public image like Nicki Minaj, Rihanna, Miley Cyrus, Iggy Azalea and criticised all these artists for "delud[ing] themselves into thinking it's 'feminism' if you get your fanny out on 'your terms'.

[77] In February 2020, she encountered criticism for taking a role as a host of the HBO voguing contest show Legendary, as she was not perceived as queer.

[87] In 2023, Jamil signed an open letter expressing "serious concerns about editorial bias" in The New York Times's reporting on transgender people.

The letter characterized the newspaper's reporting as using "an eerily familiar mix of pseudoscience and euphemistic, charged language", and raised concerns about the Times's employment practices for trans contributors.

[96] Jamil was one of 15 women selected to appear on the cover of the September 2019 issue of British Vogue "Forces for Change", by guest editor Meghan, Duchess of Sussex.

[105][106] On 10 October 2019, as part of World Mental Health Day, Jamil said she survived a suicide attempt six years earlier.

[107][108] In a 2020 episode of the talkshow Red Table Talk, she said she had also attempted suicide eight years earlier due to a nervous breakdown.

[110][111] In May 2024, Jamil said that her battle with an eating disorder has "destroyed" her bone density and damaged "my kidney, my liver, my digestive system, my heart".