Triglycerides are the primary form of fat found in both the human body and foods, especially in animal products like meat, butter, and dairy, as well as in plant oils such as soybean, olive, and canola oils. They are lipid molecules composed of one glycerol unit and three fatty acid chains.
In the context of diet, triglycerides are a major source of dietary fat and energy, delivering 9 kilocalories per gram. Foods naturally high in triglycerides include lard, suet, and processed foods rich in added fats. The overall fatty acid composition of the triglycerides present — saturated, monounsaturated, or polyunsaturated — varies by food source and affects both functional culinary attributes and health outcomes.
In cooking, triglycerides play essential roles. Their physical properties — such as melting point, smoke point, and stability — are determined by the chemical structure of their fatty acid chains. Animal fats typically contain more saturated triglycerides, which are solid at room temperature and valued for their structure in baking and frying. Plant-based oils generally have more unsaturated triglycerides, which are liquid at room temperature and contribute to food texture, moisture retention, and flavor dispersal. The manipulation of triglyceride-rich ingredients in culinary practices, such as clarifying butter, rendering lard, or emulsifying dressings, relies upon the behavior of these molecules under heat and mechanical action.
Dietary intake of triglycerides has direct effects on human health, particularly regarding blood lipid profiles and cardiovascular risk. After ingestion, triglycerides are broken down in the digestive tract and absorbed into the bloodstream, where they are reassembled and transported in lipoproteins. Elevated blood triglyceride levels, often resulting from excessive dietary fat or carbohydrates, are associated with an increased risk of atherosclerosis, pancreatitis, and metabolic syndrome. The type of fatty acids present in dietary triglycerides also influences health; high intake of saturated and trans fatty acids is linked to adverse cardiovascular outcomes, while unsaturated fatty acids (notably omega-3s) are considered protective. Regulatory authorities, including the World Health Organization and the United States Dietary Guidelines, recommend limiting saturated fat intake and replacing it with unsaturated fat sources to maintain healthy blood triglyceride levels.