Your starting weight should already be entered during the signup process. However, if you need to adjust it, just go tap on the Main Menu to access your Profile and tap on Manage Profile.
It is important to be accurate with this weight when you first start! Overestimating or underestimating your starting weight will change your macros accordingly. Please note that this is not a goal weight entry either. This is the weight you are currently at before you begin your first Fat Loss, Maintenance, or Muscle Gain phase.
As you move through the phases of Fat Loss or Muscle Gain, you will not need to update the starting weight. The reason for this is that if you are seeing progress, then the macros you have been given are working as is and we want to keep it that way! Updating the starting weight will change those macros. If you do reach a plateau on a certain phase, you can always move to the next phase.
If you move to a different plan (for example, from Fat Loss to Maintenance) you WILL want to update your starting weight at that time. If you ever have a question about when it's appropriate, don't hesitate to reach out to StaxChat!