Have you lost that loving feeling? Your diet may be partly to blame. In her new book, Eat Your Way to Sexy, nutritionist Elizabeth Somer draws a connection among food, exercise and a sexier attitude.

“The key to feeling totally alive is feeling confident and comfortable in your own skin and energized and playful,” the author of Food and Mood says. “If you think beyond just depression and just fatigue, you start talking about a life that’s truly vital, and that’s a life that’s sexy.”

We spoke with Somer about getting that confidence back, foods that will help spice things up and how to keep from destroying your hard work during the holidays. An edited version of the interview follows.

MORE: So what is sexy, and why do you think so many women have lost that feeling about themselves?
Elizabeth Somer: If you ask somebody, ‘What does it feel like to be sexy?,” usually I get things like, “Well, you know, when I put my little black dress on, that helps.” Or a guy will say, “All I have to do is look at cleavage.” But let’s go beyond that—what drives you to put the dress on in the first place? When you get people to start dieting into that, often they’ll say, “Gosh, I haven’t felt that way in a long time. I haven’t felt that joie de vivre, that playfulness, that confidence.”

Our lives are so hectic and so busy, we stop taking care of the most important thing in our lives: ourselves . . . You only get one chance, one life, one brain, and you’d better take care of it. I think people, at least in this country, certainly not in all countries, are so frantic that we stop looking at the really, truly important thing in life, which is taking care of ourselves.

MORE: That seems to be a daunting task for a lot of people.
ES: I think people think, “Oh, gosh, to eat right, it’s going to cost a lot, and my money is tight these days,” or, “It’s going to take a lot of time,” but that’s just not true. One thing that’s important to do—and we have tons of research to show this—is to eat breakfast. People who eat breakfast have much better moods throughout the day, they think more clearly, they’re more creative, they perform better at work and school, they’re less prone to food cravings, they’re less likely to gain weight, and they have more energy throughout the day. So they’re more ready for sex at night.

All it takes is one minute to eat a nutritious breakfast. It could be a bowl of whole grain cereal with milk and a handful of blueberries. It could be whole wheat toast with peanut butter on top and orange juice. You can have dinner on the table in 15 minutes. There’s no reason to order the junk takeout that is adding to the American waistline and reducing our sex drive. Put some salmon under the broiler, put a sweet potato in the microwave and grab a bag of romaine lettuce. Done.

MORE: How does food help when it comes to feeling sexier?
ES: Well, first, you can’t eat junk and then just throw a couple of sexy foods into the meal and expect to feel better. You really have to follow the 75 percent authentic rule: 75 percent of the time, three quarters of the plate, three out of four bites, need to be a real food that doesn’t come in a box or a bag or a carton. It’s from the produce aisle, it’s whole grains—those kinds of things. And then you can still have a doughnut or whatever, but 75 percent of the time you have got to eat real. But, that said, let’s say you’re eating lots of fruits and vegetables, and you’re eating regularly throughout the day, then there are some foods that have an extra punch.