--- title: William Warr | TIME description: Warr is a global health policy expert, visiting professor at Imperial College London, and an honorary fellow at Oxford. He previously served as the senior adviser on health and technology to the U.K. Prime Minister canonical: https://time.com/author/william-warr/ og:title: TIME | Current & Breaking News | National & World Updates og:description: Breaking news and analysis from time.com. Politics, world news, photos, video, tech reviews, health, science, and entertainment news. og:url: https://time.com/author/william-warr/ og:site_name: TIME og:image: https://static.time.com/v3/assets/bltea6093859af6183b/bltde093bcdab65f2d0/6988d9b9bc6cfc69913e2a3c/time-logo.jpg?branch=production og:image:width: 300 og:image:height: 300 og:image:alt: Breaking news and analysis from time.com. Politics, world news, photos, video, tech reviews, health, science, and entertainment news. og:type: profile twitter:card: summary twitter:title: TIME | Current & Breaking News | National & World Updates twitter:description: Breaking news and analysis from time.com. Politics, world news, photos, video, tech reviews, health, science, and entertainment news. twitter:image: https://static.time.com/v3/assets/bltea6093859af6183b/bltde093bcdab65f2d0/6988d9b9bc6cfc69913e2a3c/time-logo.jpg?branch=production --- # William Warr ## William Warr _Warr is a global health policy expert, visiting professor at Imperial College London, and an honorary fellow at Oxford. He previously served as the senior adviser on health and technology to the U.K. Prime Minister_ ## William Warr *  Mar 4, 2026 ### [Healthcare Is AI’s Hardest Test](https://time.com/7382493/ai-healthcare-doctors/) The real challenge isn’t whether AI works. It’s knowing when, writes William Warr. [IDEAS](/section/ideas/) *  Sep 15, 2025 ### [Weight-Loss Drugs Won’t Make Us Healthy](https://time.com/7316760/weight-loss-drugs-william-warr-ultra-processed-foods/) "Children are growing up in a food environment designed to make them sick," writes William Warr. [IDEAS](/section/ideas/) Meta: null ```json [{"@context":"https://schema.org","@type":"Organization","@id":"https://time.com/","name":"TIME","url":"https://time.com/","logo":{"@type":"ImageObject","url":"https://time.com/images/logo.png","width":528,"height":156},"foundingDate":"March 3, 1923","sameAs":["https://www.facebook.com/time","https://www.instagram.com/time/?hl=en","https://twitter.com/time","https://www.pinterest.com/timemagazine"]},{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"https://time.com/","name":"Home"}},{"@type":"ListItem","position":2,"item":{"@id":"https://time.com/author/william-warr/","name":"William Warr"}}]},{"@context":"https://schema.org","@type":"Person","@id":"https://time.com/author/william-warr/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/author/william-warr/"},"name":"William Warr","jobTitle":null,"description":"Warr is a global health policy expert, visiting professor at Imperial College London, and an honorary fellow at Oxford. He previously served as the senior adviser on health and technology to the U.K. Prime Minister","url":"https://time.com/author/william-warr/","worksFor":{"@type":"Organization","name":"TIME","url":"https://time.com/"}}] ```