When importing steps from Huawei Health to Fddb you have to distinguish between two separate issues - on the one hand the sheer number of steps and on the other hand the associated calorie consumption.
Number of steps
The number of steps is offset against activities, as certain activities can also contain steps, such as walking or jogging. These are subtracted from the total number of steps per day so that there is no double calculation of the steps and the associated calorie consumption.
Huawei Health does not pass on a fixed calorie consumption to Fddb for steps counted without an associated activity. Therefore, Fddb has decided to calculate a fixed calorie consumption of 0.044 kcal per step for these steps. I.e. for 10,000 steps, recorded via the Huawei Health app (or a connected tracker), you will be credited with 440 kcal.
This definition can lead to deviations in the calorie consumption shown in the Fddb app and in Huawei Health and should only be viewed very superficially, as the actual consumption differs from person to person.