Q: I need more energy—I feel like I'm dragging during the day. Can a diet change increase my energy?
A: Yes, definitely. But before we look at how food choices can help, let's cover a few equally important basics: First, are you sleeping enough? Look at any 5-year-old. Children have energy to burn, and it's not from coffee or energy drinks. It comes from the fact that they go to bed early and sleep for 10 hours or more every night. High energy is the natural state of a well-rested person. So make a rule: Lights out by 10 p.m. Stick with it, and you'll see the difference.
Second, are you exercising enough? Sedentary living is a vicious cycle. If you're sedentary, your muscles and heart lose their ability to handle exercise. The resulting lack of energy means you'll tend to stay inactive. To break out of that cycle, start with a brisk walk for 30 minutes a day or an hour three times a week (see your doctor first, to make sure your heart and joints are up for it), and gradually increase the intensity and duration of your exercise sessions.
Third, sometimes there is a medical cause for a loss of energy. Your health care provider can check for anemia, thyroid problems, depression, or other contributors. Whether you follow a vegan diet or not, you should take a vitamin B12 supplement.
Q: OK, what about food?
A: What keeps your muscles revved up are molecules of glycogen. If you were to view glycogen under a powerful microscope, it would look like a long, branching string of beads. Each "bead" is a molecule of glucose, or simple sugar. Marathoners eat lots of rice, bread, pasta, and other starchy foods, because when starches are digested, they release glucose that the body stores in the muscles and liver, like extra batteries.
My two favorite endurance athletes are Brendan Brazier and Scott Jurek. Most people would be proud to have run a marathon. Brazier leads the pack in Ironman triathlons and 50-kilometer ultramarathons, and is as particular about food as a Formula One driver is about racing fuel. Brazier's diet is loaded with healthful carbohydrates. Early in his racing career, Brazier found that animal products slowed his recovery after exercise. His energy returns quickly with a totally vegan diet, and he is ready to compete again. And perhaps no one has more energy than Scott Jurek. In 1999, Jurek entered the 100-mile Western States Endurance Run. He and 334 other runners set off running, and not only did Scott win that racehe won the race every year for the next six years, setting the course record in 2004 at 15:36:27. Like Brendan, Scott leaves the pepperoni pizza, sausage omelets, and all other animal products off the menu, sticking to a high-carb, vegan menu.
Q: But not all carbohydrates are the same, are they?
A: No, and that's an important point. For energy, you want carbohydrates with staying power. The glycemic index shows you which ones those are. Foods that score high on the glycemic index, such as sugar, white and wheat breads, white potatoes, and most cold cereals, digest too rapidly and cause your blood sugar to spike. Then, as your blood sugar falls, your energy flags and cravings kick in.
But low glycemic-index foods have a much gentler effect on blood sugar, helping you avoid highs and lows. Some good choices are oatmeal, beans, rye or pumpernickel bread, pasta (yes, even if it's made of white flour, it has a low glycemic index), yams, and sweet potatoes. There is another reason to avoid high-glycemic-index foods: They tend to boost serotonin in the brain, which can make you sleepy. This effect is blocked by lower-glycemic-index foods and also by high-protein foods. So that strip of veggie bacon or scrambled tofu in the morning before your bagel will help keep your energy from flagging.
Q: Are there some foods that really sap your energy?
A: In addition to sugary and high glycemic-index foods, pay attention to fatty foods. You know the slowdown that many people experience after a meal, especially after huge holiday dinners loaded with meat, cheese, and gravy? It turns out that animal fats—and any sort of saturated fats—tend to make the blood more viscous, or "thicker." Your blood becomes more like oil and less like water. I suspect that is the main reason many people feel tired after heavy meals, and is also why so many people who go vegan notice that their energy increases.
Q: How about coffee or energy drinks?
A: I can't say I recommend either one. The main function of drinking caffeinated beverages every morning is to combat the withdrawal that comes from having had them the day before. Caffeine withdrawal reduces alertness and mental clarity, and causes headaches. A morning cup of coffee simply hoists you temporarily out of your withdrawal.
Energy drinks such as Red Bull combine caffeine (about the same amount as in a small cup of coffee) with the amino acid taurine and other additives to increase alertness and boost athletic performance. Whether its effects are caused by caffeine or by its other ingredients is not yet clear, but many people report a withdrawal syndrome very much like caffeine. The bottom line: Get a good night's sleep; exercise regularly; eat plenty of healthful complex carbs and plant-based protein; skip the sugar, fatty foods, and caffeine—and you should have energy to burn.