Is it Unhealthy to Eat lipids? No, it isn't, we need lipids. However, some types of lipids like saturated fats and trans fats are harmful.
Lipids serve various purposes in the organisms of animal and plants. Lipids in the form of triglicerides are called fats, like olive oil, sunflower oil, beef fat, lard , etc…. These are mainly energy reserves. There are various other lipids that serve more specific purposes. Lipids are used to make cell membranes, to make nerve coatings and also to perform signalling functions around the body, in the form of hormones.
The main characteristic of lipids is their insolubility in water (for example, a mixture of oil and vinegar, made as a salad dressing, separates spontaneously after a while). Lipids do dissolve in organic solvents.