What to wear when you are 5'1 and 160 lbs

I say wear whatever you want. With one provision. Just make sure it's not too tight. No one minds a large woman dressing sexy. We DO mind a woman that wears clothes that are two sizes too small. Be comfortable. The better you feel, the better you'll look.

Very well said by Bonestructure.

It is very important to wear your size, does not matter what your size is. Always wear dresses only of right size. Smaller size dresses give greasy look. Try to wear dress with vertical lines or designs. Avoid bog and bold design dresses.

Same way avoid dresses in 2 color they will divide you appearance in two part. try to wear outfits of one color or with same design that will give single and taller look.  Back dresses are blessing for you. 

Read here some basic tips about this year plus size fashion.

http://www.gownsexpress.com/blog/plus-size-fashion-hits-the-grounds-of-2012.html