Certain foods, he says, can be as powerful as drugs. Dr. Drewnowski and others have identified an opiate-like effect when we eat high-fat, high-carb stuff like chocolate. Fat and carbohydrates (especially in the form of sugar) elevate serotonin, a chemical in the brain that regulates mood. But serotonin levels can plummet during periods of depression–and during long stretches of rigorous exercise. Which explains why jilted lovers and sweaty hikers both reach for a pint of Ben and Jerry’s.
But is serotonin the only thing driving our junk-food fantasies? We asked our experts if hikers might be craving a Hershey’s bar or bag of Fritos because our bodies aren’t getting enough of the nutrients those snacks contain. On this question, the jury is still out. Dr. Drewnowski calls the notion “complete nonsense,” but Mary Howley, a registered dietitian and backcountry nutrition counselor, disagrees. “Yes, fat and sugar are mood-improving comfort foods, but they also help us get up the trail,” she says. “The sugar provides quick energy to the brain, and the fat provides long-term energy to the muscles.”
Either way, you have a green light to eat junk. “The diet rules change when you’re backpacking,” says Marsha Beckerman, a registered dietitian who’s in charge of meal planning for more than 500 athletes at the University of Texas, Austin, and helps create menus for mountaineering expeditions. “Backpackers, like any endurance athletes, have permission to eat. There is no such thing as junk food if it helps get you up that hill.”
Beckerman recommends that people on a typical weeklong hike eat about 50 percent more than they do at home. That means you can–and should–consume fat in the form of nuts, peanut butter, and oils. “Fat is your friend on long hikes,” she says. “The wilderness is no place to skimp on calories, so take tuna that’s packed in oil, not water.”
NOLS is also trying to convince its students, normally a weight-conscious bunch, to embrace the idea of eating fat. “For a 3-week NOLS hiking or skiing course, we recommend a diet of 3,000 to 4,500 calories a day,” says Howley. She and Beckerman both emphasize the importance of variety, though, noting that only a combination of carbs, fat, and protein will provide the necessary energy and muscle recovery for a hard, mountain hike.
But what about the beer? “Obviously there’s no nutritional need,” laughs Howley. “But if it satisfies a craving that’s based on an emotional need to celebrate, then why not?”
Note: To purchase the 2002 NOLS Nutrition Field Guide ($15), call (307) 332-8800, or write to firstname.lastname@example.org.