--- title: Thanksgiving Day 2015: Turkey's Impact on Your Body description: Why Thanksgiving makes you sleepy canonical: https://time.com/4124271/thanksgiving-day-2015-turkey/ author: Alexandra Sifferlin article:opinion: false article:content_tier: free article:published_time: 2015-11-24T15:12:47.000Z article:modified_time: 2026-05-11T04:50:34.247Z article:section: Health og:title: This Is Your Body on Turkey og:description: Why Thanksgiving makes you sleepy og:url: https://time.com/4124271/thanksgiving-day-2015-turkey/ og:site_name: TIME og:image: https://static.time.com/v3/assets/bltea6093859af6183b/bltde093bcdab65f2d0/6988d9b9bc6cfc69913e2a3c/time-logo.jpg?branch=production og:image:width: 1200 og:image:height: 675 og:image:alt: TIME og:type: article twitter:card: summary_large_image twitter:title: This Is Your Body on Turkey twitter:description: Why Thanksgiving makes you sleepy twitter:image: https://static.time.com/v3/assets/bltea6093859af6183b/bltde093bcdab65f2d0/6988d9b9bc6cfc69913e2a3c/time-logo.jpg?branch=production --- # This Is Your Body on Turkey by [Alexandra Sifferlin](https://time.com/author/alexandra-sifferlin/) and [Heather Jones](https://time.com/author/heather-jones/) Nov 24, 2015 3:12 PM UTC by [Alexandra Sifferlin](https://time.com/author/alexandra-sifferlin/) and [Heather Jones](https://time.com/author/heather-jones/) Nov 24, 2015 3:12 PM UTC It’s that time of year again, when we loosen our belt buckles and prepare to eat a whole lot of [turkey](http://time.com/money/4124279/cheap-thanksgiving-turkey-prices/). And mashed potatoes. And gravy, and stuffing. And cranberry sauce. Eating turkey—and especially overeating turkey—has some very real biological effects. You’ve surely heard that turkey contains compounds that make you sleepy, but that’s not all that’s going on (and that’s not entirely true, either). We asked Matthew Hartings, an assistant professor of chemistry at American University, to break down all the things that happen inside our bodies when we feast:  ```json [{"@context":"https://schema.org","@type":"NewsArticle","@id":"https://time.com/4124271/thanksgiving-day-2015-turkey/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/4124271/thanksgiving-day-2015-turkey/"},"headline":"This Is Your Body on Turkey","datePublished":"2015-11-24T15:12:47.000Z","dateModified":"2026-05-11T04:50:34.247Z","description":"Why Thanksgiving makes you sleepy","url":"https://time.com/4124271/thanksgiving-day-2015-turkey/","keywords":["Nutrition","Turkey","Thanksgiving"],"thumbnailUrl":"","author":[{"@type":"Person","name":"Alexandra Sifferlin","jobTitle":null,"url":"https://time.com/author/alexandra-sifferlin/"},{"@type":"Person","name":"Heather Jones","jobTitle":null,"url":"https://time.com/author/heather-jones/"}],"articleSection":"Health","image":[],"publisher":{"@type":"Organization","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":"/section/health/","name":"Health"}},{"@type":"ListItem","position":2,"item":{"@id":"/tag/nutrition/","name":"Nutrition"}},{"@type":"ListItem","position":3,"item":{"@id":"https://time.com/4124271/thanksgiving-day-2015-turkey/","name":"This Is Your Body on Turkey"}}]}] ```