Dina believes she is eating right, but she can't seem to shed those last 15 pounds. Fellow mom Evita shares her frustration. "I think I'm making healthy choices with my food," she says, "but I just don't understand why the weight isn't coming off." After Rachael challenges each woman to keep a food diary of everything they put into their mouths in one week, celebrity nutritionist Christine Avanti analyzes their menus and give them the skinny on their choices.

"It's deceiving because a lot of times meals seem like they're low in calories because they're smaller," Christine tells Rachael, "but actually they're packed with calories because maybe they have too much fat in them." To help Dina and Evita -- and the countless others trying to lose those last few pounds -- Christine weighs in on the dos and don't of dieting.

• You need to eat four meals a day -- one every fours hours -- to train your metabolism and to keep it at a high rate.

• Keep your daily caloric intake at an even level. After a day of indulging, the tendency for most people is to drastically reduce the amount of food they normally eat. "The metabolism is very confused - you have fat storage with the big day, and then you're slowing down your metabolism with the small food day."

• Be aware of the fat content of your food because size can be deceiving -- even a small bowl of nuts can have up to 30 grams of fat. The daily intake of fat for women should be only be about 40 grams, or 10 grams per meal.

• You should be getting a nice balanced meal of one part protein, two part carbs. Be wary of many dairy products, which actually have twice as much fat as protein per ounce.