Definition: Fats are substances that give an object its weight, usually in a liquid or solid state. These include fats like butter, oil, and dairy products, as well as complex carbohydrates and lipids found in the body. Definition: Fats are essential components of our cells and play crucial roles in metabolism, energy production, and signaling pathways. They help maintain cell integrity, protect organs, and regulate body temperature. Fatty acid is a chemical molecule that comprises the fatty substance of an organism, consisting primarily of three types: cholesterol (a white or yellowish gel), triglycerides, and bile acids.