protein. protein keeps us feeling satisfied throughout the day. we avoid those hunger pangs. >> reporter: nutritionists say there are some drawbacks but you're not anti-paleo but not the biggest fan. >> you know i think the paleo diet is a fine as a jump-start to weight loss. the problem i have with it eliminates other healthy feuds. if you are going to follow paleo for an extended time, i would recommend supplementing your diet with a calcium vitamin d supplement.รง >> reporter: modified paleo maybe renaissance man diet. >> right. >> reporter: in addition a lot of your time will be spent cooking in your kitchen, but michelle says she doesn't mine. >> it is a lot more work. but it's worth it. >> reporter: juju chang, abc news, new york. >> all right. so, off the bat, how long did cavemen live? >> i don't know. >> not very long. they died like in their 20s, 30s, their teeth rotted. >> good point. >> whole grains are not that bad for you. >> i want to know, how do they