The thermogenic effect of food (TEF) is highest for which macronutrient?

The thermogenic effect of food (TEF) refers to the increase in metabolic rate following the ingestion of food, primarily due to the energy expended in digesting, absorbing, and metabolizing nutrients. Among the macronutrients, protein has the highest thermogenic effect. This is because the body requires more energy to break down proteins compared to carbohydrates and fats, which leads to a greater increase in energy expenditure during the digestion and metabolism processes.

Protein digestion involves complex processes such as deamination and transamination that not only require energy but also involve the synthesis of new proteins. This results in a higher caloric expenditure per gram consumed, estimated at about 20-30% of the energy content of protein being expended during its processing. On the other hand, carbohydrates generally contribute about 5-10%, and fats contribute even less, around 0-3%.

This high thermogenic effect of protein can play a significant role in weight management and metabolic health, which is crucial for patients dealing with obesity. Understanding the TEF is vital when formulating dietary recommendations for weight loss or maintenance, emphasizing a higher protein intake can be advantageous for promoting thermogenesis and enhancing overall energy expenditure.