Tell them (your girlfriends) that the Paleo diet is the way to go - steak, bacon, fried veggies - good stuff.
The elephant in the room in the Paleo diet is no refined sugar. A real deal-breaker for most girls (and guys) - no dessert, pie, ice cream, cake, cookies, chocolates, sodas, candy, donuts, or anything else with sugar in the top 4 on the ingredient list.
Sadly, this is the one thing that makes the most difference, not just for weight loss, but in how you feel. I have much more energy since I cut out sugar. And my tastebuds have even come back - regular food tastes so much better now. I'm eating all the time, snacking on nuts and fruit constantly in between meals, and I'm gradually losing weight without a whole lot of exercise (I have a desk job).