Expect to see freshman Rep. Joe Wilson (R-S.C.) several pounds lighter when he comes back from recess.

The Congressman will be subsisting for 10 days on a diet of dehydrated food, bottled water, sun and sky as he treks 100 miles in the New Mexico Rockies with his son Hunter.

That’s also why Wilson has been seen wearing his hiking boots on the House floor and why, one recent afternoon, he was found walking up and down, up and down the Capitol steps with Hunter. Wilson was getting ready for the hike by breaking in his brand new water-resistant Gore-Tex boots. Wilson admitted later that his colleagues were “somewhat surprised” to see him hiking the Capitol steps, but “they were really supportive when they found out what I was doing.”

Hunter, 17, admitted last week that the experience was “very strange” but added that it was fun.

Wilson will be one of a handful of adult supervisors in a group of 10 Boy Scouts attending a trek offered annually in the Philmont Scout Ranch in New Mexico.

Wilson said he won’t mind the diet of dehydrated food for 10 days. “You’re so hungry, it’s wonderful,” he said, adding that the trek is “an extraordinary example of organization.” Each day of the trip begins with a four- to five-hour-long hike to a base camp, where activities such as branding, rock-climbing and fly-fishing are on hand for the Scouts.

Wilson, braving the trek for the second time — though for the first time with Hunter — said his goal is “to complete the trek without ever asking the Scouts to stop, slow down,” adding that he doesn’t want to hold them back. The key to doing that is foot care, Wilson said, making sure no blisters develop. “The bottom line is having the proper boots, proper socks,” he said.

Wilson first completed the trek in 1999 with his son Julian.

Besides breaking in his boots, Wilson has been measuring his steps — literally. He has a pedometer attached to his belt clip that keeps track of how far he walks each day — 12,000 to 18,000 steps on a typical day, he said.

As preparation for the hike, Wilson said he’s been avoiding elevators and escalators. And he has become inspired by the example of the late Sen. Strom Thurmond (R-S.C.), in whose office Wilson was once an intern. One of the reasons for Thurmond’s longevity and health was “virtually his entire service here he made an effort to use the stairs instead of elevators and escalators when he could,” Wilson said.

Wilson has a long history with the Scouts. All four of his sons have been, or are on their way to becoming, Eagle Scouts, and Wilson himself is the Republican co-chairman of the House Boy Scout Caucus. He was briefly a Boy Scout in his youth, but Wilson said his troop disbanded because it was hard to retain a scout master. That’s why Wilson said he’s grateful for the level of commitment and organization he has found among adults who volunteer for the trek. “Scout leaders and parents of Scouts, they’re very dedicated to promoting the development of young people,” he said.

Also impressive is the Boy Scout imperative to leave no traces of human use behind in campsites, Wilson said. The meticulous picking up of garbage, scattering of campfire ashes and practice of conservation is what keeps the ranch extraordinarily beautiful, he said.

Wilson won’t be the only Congressman in Philmont over the break. Rep. Pete Sessions (R-Texas) will spend recess there doing day hikes with his family, including son Bill, 14.

Sessions has one piece of advice for Wilson. “Be in shape before you go,” he said, adding that “The older you get, the harder it is.” He has done a Philmont trek six times, three times as an Eagle Scout and three times as an adult volunteer.

Sessions said Bill will be able to do the trek two years from now, and he’s already looking forward to joining him on it. Philmont is “my favorite place in the whole world,” Sessions said.