This goal has the following fine print specified by mwalla:
I decided to beemind the moving average of my daily weight instead of the daily values themselves. Data entry and trend calculation are done in a Tasker app, which also populates an email that I send to IFTTT, which sends the trend value here, logs a 1 in my weigh daily goal (weighly), and logs the actual weight value to a google spreadsheet for posterity.