They're great for you!
Serving Size 100g
Calories: 160
Fat: 14.66g
Carb: 8.53g
Protein: 2g
Fiber: 6.7g
Potassium: 485 mg
http://www.nal.usda.gov/fnic/foodcomp/search/Avocados have 60% more potassium than bananas. They have the highest fiber content of any fruit, including 75% insoluble and 25% soluble fiber. They are rich in B vitamins, as well as vitamin E and vitamin K. About 75% of an avocado's calories come from fat, most of which is monounsaturated fat.
Data suggest the presence of an appetite depressant in avocado and that avocado pulp interferes with hepatic fat metabolism.
http://www.ncbi.nlm.nih.gov/pubmed/12097685High avocado intake has been shown to have an effect on blood serum cholesterol levels. Specifically, after a seven day diet rich in avocados, hypercholesterolemia patients showed a 17% decrease in total serum cholesterol levels. These subjects also showed a 22% decrease in both LDL (bad cholesterol) and triglyceride levels and 11% increase in HDL (good cholesterol) levels.
http://grande.nal.usda.gov/ibids/index.php?mode2=detail&origin=ibids_references&therow=45635