The main differences between cottage cheese and ricotta cheese are the texture and byproducts from which each cheese is made. Cottage cheese is lumpier and heavier than ricotta cheese, while ricotta cheese is grainier than cottage cheese. Cottage cheese is a byproduct of curd, while ricotta cheese is a byproduct of whey.
In most recipes, cottage cheese is a perfectly acceptable substitute for ricotta cheese in warm cheese dips and Italian dishes like lasagna and stuffed shells. The texture difference may be noticeable, but the calorie savings are noticeable, too. On average, a half-cup of low-fat cottage cheese has 81 calories and 1 gram of fat compared to the same amount of part-skim ricotta cheese, which has 171 calories and 10 grams of fat.