Your extra calories should come in the form of carbohydrates, which are digested quickly and provide sustained energy during winter travel. Regardless of the season, you should get 60 to 65 percent of your calories from carbohydrates; 20 to 25 percent from proteins; and 10 to 15 percent from fats. How do you figure out those ratios? You can menu-plan with a calculator, or use the Nutrition Analysis Tool at www.nat.uiuc.edu. Simply enter your proposed trail menu and the Tool does the rest.
*Calculated from the NAT Energy Calculator for a 165-pound, 35-pound, 35-year-old male.