FatOK estimates the fitness state from the four points of view:
1. Health (waist-to-height ratio)
2. Traditional body mass index (the estimation of "thickness or thinness" by weight and height)
3. US Army Body Fat Standard (the estimation of the body fat percentage by the height and the circumferences of waist, neck, and maybe hips)
4. Fitness (using the "military" method above to estimate the body fat percentage)

For the selected goal you see your progress to this goal.

FatOK notifies at the time to update the measurements for your main goal two weeks since the last measurements. The two weeks interval is the minimal time to unambiguously estimate whether you lose or gain your body fat in the case of healthy slimming. You may also set the notification time on the notification day.

FatOK also estimates the caloric intake needed to decrease, maintain or increase the body fat percentage.

In general FatOK estimations of fitness are approximately valid for the adults of the age 21 years old or older. Military Body Fat Standard, body fat percentage, and caloric intake estimates are approximately correct only for the adults of the age 17 years and older. The Waist-to-height ratio estimations are approximately valid not only for adults but for children also.

FatOk works in close cooperation with the Apple iPhone Health app. In particular, it stores the weight, waist, height, and body fat percentage in the common Health App database and you may watch the complete plot of your weight, waist, and body fat percentage with time in the Health App.

Fat OK syncs with your favorite smart bathroom scale if it can sync with the Apple Health app.

You should be aware the FatOK gives only the estimations. These estimations are approximately correct for the majority of people but not for all. In case of doubt always seek the advice of your physician or other qualified health providers.

FatOK is not a medical device or application. It is not designed or intended for use in the diagnosis of disease or other conditions, or in the cure, mitigation, treatment, or prevention of disease.