Avoiding Surcharges. Because airlines charge a peak travel day surcharge on the most popular days of travel -- Sunday, Monday and Friday -- you can get the best discounts on those off-peak days. However, during the summer, peak and off-peak travel days do not really exist.
Proteins are essential nutrients for the human body. They are one of the building blocks of body tissue, and can also serve as a fuel source. As a fuel, proteins contain 4 kcal per gram, just like carbohydrates and unlike lipids, which contain 9 kcal per gram.
Protein is one of three primary types of macronutrients that provide your body with energy, regulate its functioning and facilitate development.hoto Credit ColorBlind Images/Blend Images/Getty Images. Protein is one of three primary types of macronutrients that provide your body with energy, regulate its functioning and facilitate development. A protein consists of a chain of amino acids that your body uses for energy and to make new proteins.