The medical field (which i am in) discourages the Atkin's diet. Too much fat intake which may drop weight but will cause fatty plaques in arteries. The human body is designed to run on glucose (sugars/carbs).
BUT. Here is what i did for breakfast to cut my fat. Note that i'm a vegetarian by nature so bear with me.
I went to making omelettes with egg-white products (i buy the generic... no fat, no carb, its raw protein) and i scramble it in with some soy-rizo (chorizo... but soy) to add some more flavour. Also use some veggies (spinach in small amounts, onion, pepper, jalapeno). Make a 2-3 egg equivalent omelette. Side of fresh fruit (apple, orange, banana, strawberries, etc...).
Its rather low in calories and fat. Adds a small amount of carbs and a lot of protein. Soy products for meat replacement should be a serious consideration if you want to drop weight. Soy diets also bind cholesterol lowering your VLDL and LDL cholesterol.
Also, one GREAT thing i did. Mind you i'm 24 and get made fun of a lot for this. Metamucil. It also lowers cholesterol and keeps you regular.
Lastly... FIBER FIBER FIBER. Prevents colon cancer and helps with all kinds of other problems. I eat 1/2 cup of Fiber-1 cereal per day with soymilk and a banana.. covers almost 60% of your required fiber in one bowl.
Fad diets dont work, hands down. Everything in moderation. American diet is too high in meat and fat which leads to early heart disease, so be careful. You may be thin now... but when your kidneys fail... dont say i didnt tell you so ;)