Real butter is good for you in moderation and can actually help with weight loss.

Saturated fats have a bad reputation these days but truth is our bodies need saturated fats to function properly. 
Saturated fats :
1. help raise "good" cholesterol which helps weight loss and can also reduce the risk of cardiovascular disease.
2. Help calcium absorption for healthy bones
3. Help protect the liver from medicines and alcohol 
4. Help our brains function and repair 
5. Contributes to a healthy immune system

So it's time to throw out the unhealthy margarine with "trans fats" that are causing so many health issues in the world today and go back to buying good old butter from grass fed cows