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