If your starting weight is incorrect, you can adjust it anytime in the app.
To do this:
Go to the main Daily tab.
Scroll down to the Current Weight section and tap "Update". A calendar with your weight entries will appear.
Scroll back to the day you began your fasting journey and tap it.
Edit the weight you entered for that day and tap "Save".
Alternatively, you can use the main calendar at the top to find your first fasting log and update your weight in the Current Weight section in the same way.
If you're on paid plan, you can also check your Weight graphs:
Go to the Progress tab, scroll to the Weight section, and tap "Explore More".
Scroll through your weight log to find and edit your first weight entry.