Step 1 : Identify a strong personal purpose the “Why” by asking the question Why do I want to lose weight?. Minimum three times until you get something that deeply connect with you. The last Why should be a core motivation.
Step 2: find a least three core motivation related to your goal.
Step3: write down your core motivation and sign it
Step 4: post in visible place.

More information check this you Tube videos about this topic
• https://youtu.be/d2sqGvWYdc4
• https://youtu.be/PalTF1g51Z8
• https://youtu.be/Mrv2hdrT2WU