The journal, created by Manzanares in 2008, hit Target store shelves nationwide last month with an initial shipment of 5,500 books and 2,000 per month thereafter.
The 12-week journal is based on goal-setting, reflection and rewards. It includes organized charts to track meals and workouts, as well as helpful tips like drinking water to combat fatigue and eating small meals throughout the day to boost metabolism.
"Fitbooks" and "Fitbook Junior," designed for youths, are available on the company website, getfitbook.com.
The philosophy of "live life fit" was born out of Manzanares' own struggles with her weight and body image. Once a devout calorie counter, she now focuses on healthy lifestyle habits, such as eating balanced meals and regular exercise.
"I think that it's easy for people to get stuck in this mode when they're unhappy with their weight where they think to themselves, 'I'd be happy if I was just five pounds lighter,'" Manzanares said. "They're obsessed with the symptom of their unhappiness, not the cause. People with a 'Fitbook' are able to take their mind off the detail of every little calorie and create bigger, achievable goals."
However, if you can't ditch the calorie calculator cold turkey, Manzanares suggested a two-week time fame in which calories are logged but no longer than that.
Two weeks is adequate to understand how many calories you're consuming and how to choose a healthy meal by appearance and weight, she said.
Additionally, studies show that writing about fitness goals and meals will on average lead to 500 to 1,000 fewer calories consumed a day — no calorie counting required, Manzanares said.
"When you're happy, you find your healthy weight," Manzanares said. "People are able to achieve their goals when they are happy."