1. Energy Storage: Fats are highly efficient energy storage molecules. They contain more than twice the energy per gram than carbohydrates or proteins. This makes them ideal for long-term energy reserves, especially for animals that need to store energy for periods of food scarcity or for extended periods of activity.

2. Insulation and Protection: Fats act as excellent insulators, both for the body and for individual cells. This insulation helps maintain body temperature in cold environments. Fats also provide cushioning and protection for vital organs, preventing damage from impact or pressure.