he catches passes from tom brady, and once dated supermodel adriana lima, but there's one thing he can'tesist. >> only one burger a day to keep the conditioning away. >> he joins 22 other athletes for "the body issue" of "espn" the magazine, which celebrates the power and beauty of the human form. boston celtic isaiah thomas en ws he can dribbevle, without wearing a stitch. and football star ezekiel elliot is just as pumped up out of as ! >> get this party started! >> women athletes also show it all. tennis pro caroline wozniacki is both sexy and strong. and it was a group shoot for the u.s. national women's hockey team. last year, nba all-star dwyane wade needed convincing to be in the body issue. >> like, i would nevern evewalk around my own house by myself th no clothes on. nd>> a right now, dwyane and his wife, gabrielle union, are showing off their his and hers fashion game on their european vacation. t." ielle told "e. he wasn't always a fashionisto. >> whemen i t him, he was wearing oversized bedazzled jeans, and then something happened. now it's a s-medium. there's his man-pris.

from celebrities like kim kardashian and adriana lima and lebron james and tim tebow, the keto diet designednto a state, ketosis, your body is so low on carbs it starts burning fat for fuel. >> this will lose weight. follow some months supervised you are getting the right percentages. >> reporter: how do you do it? keto dieters drastically cut carbs to about 10% of their daily diet. and some cases, just 20 grams a day. >> put all your carbs together. what does that look like? >> maybe, a slice of bread. >> that's it. >> 31-year-old samantha has been on the keto diet four weeks. >> your breakfast looks very different. >> all my meals are different. >> so far work. samantha losing 17 pounds and counting. but she says it is not just great for weight loss. she feels better overall too. >> i have more energy. with this one running around. my workouts have gotten so much better. definitely more stamina. >> the other keys to keto. getting 20% of your calories from protein. and eating lots of fat. for some, more than 70% of their diet. >> so this glass of olive oil represents the recommended intake