The secret of happiness is freedom. The secret of freedom is courage. --Thucydides, ancient Greek historian and author
Freedom isn't about having everything you want (although, as indicated by our country's economy, this might be the pervading but erroneous popular definition). Freedom is about being able to make choices.
You can let others dictate what you should eat. It definitely requires less brain power if you do that -- but will it make you happy long-term? (Obviously not or you would still be on that diet!)
And if the secret of freedom is courage, then wouldn't you want to be brave, enter the unexplored territory of trusting your own body to tell you how much food is enough? Because isn't your real goal to be happier? Happier with your weight? Happier at work? Happier when you participate in activities with your family and friends?
Are you doing the work required to live with freedom?