Remember, all calories aren't created equal One of the biggest mistakes women trying to slim down make is treating every calorie the same. Many women think the calories from say, a granola bar, are going to be processed by the body the same way the calories from a chicken breast are. This is not true, says Kirsch. When you are trying to loose weight "skip processed carbs and excessive fruit or fat. Stick to nutrient-rich, quality calories such as chicken, quinoa and vegetables," he says.