Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
```
if you have a medical or heart condition , consult your doctor before using the fitbit service , engaging in an exercise program , or changing your diet . 

```
. OPTIONS: ["Unilateral change", "Arbitration", "Contract by using", "Choice of law", "None", "Jurisdiction", "Limitation of liability", "Unilateral termination", "Content removal"].