For more than 10 years, New York nutritionist Tanya Zuckerbrot has helped hundreds of patients in her private practice to lose weight and maintain a healthy lifestyle through her fiber-based diet. After years of success, Zuckerbrot?a Great Neck, N.Y., native who now calls the Upper East Side home?wanted her program to have a broader impact. In 2007, she published the F-Factor Diet, a book billed as a break from fad diets and an approach to permanent weight loss. There are so many different types of diets out there. What sets the F-Factor apart? Most low-carb diets have you cut out food, but the F-Factor diet has you add in high fiber food. You get to feel full all day, but every time you step on scale you?re losing weight. That?s a novelty. Why fiber? Fiber is the calorie-free part of a carbohydrate. It also has other benefits. It helps lower cholesterol, the risk for cardiovascular disease, type-2 diabetes and certain forms of cancer. We?re in a fiber deficit?the average American eats only 9 to 11 grams of fiber per day. My patients get about 25 grams a day. What about carbs? Carbs in and of themselves don?t make you fat. The problem is the carbs served in this country, the portions are so large. Think of your body as a car. If you put in too much gasoline, it will spill out. But if you eat too many carbs, your body says, ?Hmmm, I can turn this into something else.? And guess what the something else is? Fat. My patients eat carbs. But because they?re high-fiber carbs, they have more energy. How does the program work? Well, there are three stages. Step one is the most diet-like part, a jump start, and patients lose about 4 to 6 pounds. The first two weeks are about cutting back on all carbs, except cereal and fruit and crackers. You can also eat generous portions of proteins and all the vegetables you want. I believe in eating every three to four hours. By feeling full, you?re able to make a better decision about what to eat at the next meal. Step two, you add more carbs back in. Step three is maintenance. What?s the food like? The most important part is that the diet is coming from real foods. You?re not eating these chemically modified foods; it?s all natural. My patients eat fruits, veggies, whole grains, nuts, lean proteins and low-fat dairy. How did you come up with the program? Through my work with cardiologists and endocrinologists at New York hospitals. They were referring patients to me to improve their patients? clinical status through diet. After three months of adding fiber, we did their bloodwork and saw that the diabetic patients had improved, and cardiovascular patients lowered their cholesterol levels and triglycerides. Something else happened though: Everybody lost weight, and it wasn?t something I intended to do. How much weight do people lose and how quickly? After two weeks, you notice a difference: Your stomach is flat. There?s a myth that fiber bloats you. If anything, it gives you the best stomach ever because you?re going to the bathroom more often. A guy down in Florida on the diet has lost 196 pounds as of now. I like to go out to eat pretty often though. Can I still follow the diet? That?s another beauty of the program. My patients can dine at any restaurant, and for New Yorkers, that?s the most freeing thing in the world. I always say that for dieting, you should not sacrifice the social aspect of eating. I look at Menupages.com with my patients and discuss the food on the menu with them to figure out what they can eat. What about you? Do you practice what you preach? I live by the diet. I?ve been doing it for 10 years. I?ve been pregnant twice on it. It allowed me to eat healthy during my pregnancies but not gain excessive weight. As a dietician, people think you never eat. It?s the opposite though. I?m obsessed with food. The holiday season is often a hard time for people looking to control their weight. What kinds of tips do you have for people this time of year? The average American gains between 7 and 11 pounds between Thanksgiving and New Year?s. My recommendation for people who work in an office is to keep healthier snacks around: string cheese, crackers, nuts, microwavable popcorn, fresh fruit, packages of oatmeal. All those high-fiber choices will help keep you feeling full. My tip for people at parties is this: Don?t just take the first thing that comes by you on a tray. If there?s crudités or chicken skewers, eat those first and then give yourself a treat, eat that pig in a blanket. Also, have a high-fiber protein snack before you get there so you arrive somewhat satisfied. What else do you have in the works? I?ve started a new website with four other women dieticians in their twenties and thirties: www.skinnyandthecity.com. The site combines diet and beauty tips with fashion. It?s a guide to staying healthy but keeping the lifestyle you want. That?s my passion?helping people, and especially women, to look and feel their best.