Regular body-weight logs help us estimate accurate trend-weight numbers and hence accurate calorie recommendations for you. It is normal to have day to day body weight fluctuations.
In some cases, we see fluctuations as high as 2kgs in a day for users. However, these fluctuations, which in most cases are water-weight, do not affect the recommendations big time
Regular logging of weight, if not daily, at least 3 times a week to get accurate recommendations.