The Foods Your Body Needs in Your 20s and 30s

At this stage, runners’ lives diverge in a few different directions. Some train more intensely on college teams, in pro groups, or as recreational racers. Others shift their focus to work or family, logging miles on the side for physical and mental well-being. “For some people, it might be their peak, and they’re running their highest mileage and longer distances,” Sakiko Minagawa says, a registered dietitian for the division of sports medicine at Nationwide Children’s Hospital in Dublin, Ohio. “For others, it actually might be less because they now have a full-time job or full-time parenting.” What you eat in your 20s and 30s can help power you no matter which route you take.

Regardless of your lifestyle, your body’s still building new bone, at least until your mid- to late 20s, registered dietitian nutritionist Yasi Ansari says. The food you eat contributes to this construction project, leaving you with stronger scaffolding for the rest of your life. Proper fueling also regulates your hormones, powerful chemical messengers that guide everything from your menstrual cycle to your mental health to your muscle growth.

Pregnant, or trying to be? Continuing to consume a variety of macro- and micronutrients prepares your body to grow another healthy human. Once you’re expecting and while you’re breastfeeding, your overall energy needs—and requirements for some vitamins and minerals—increase even more.

Tips for What to Eat in Your 20s and 30s

Ditch Diets

Some runners aim for a specific number on the scale, or a “race weight.” Starting with this goal in mind can be counterproductive: One 2019 study found collegiate athletes who aimed for a thin physique had 89 percent more injuries than those who didn’t put a priority on being lean. Instead, focus on eating a wide range of foods that make you feel strong and healthy, registered dietician nutritionist Lauren Antonucci says.

Track Your Cycle

Reproduction is often one of the first functions that shuts down when you’re underfueled, making your period a powerful gauge of your energy intake. Keep tabs on your cycle, and if it’s erratic or halts altogether (and you’re not pregnant), talk to your doc or an R.D.—you might need more fuel, or specific foods to support your training and life. When things are flowing normally, nutrition tweaks can help you work with your hormones to get the most out of your training, sports dietician Lydia Nader says. For instance, increasing nutrients like magnesium, zinc, and omega-3 fatty acids around the time of your period can decrease inflammation, easing PMS symptoms.

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Add Iron

Your body needs iron to build two key proteins, hemoglobin and myoglobin, which transport and store energizing oxygen. Women lose this vital mineral each month in period blood, and runners leech iron through each strike of their foot on the ground. While teen girls need it too—about 15 milligrams daily—adult women’s recommended intake increases to 18 milligrams. Double those amounts if you’re vegetarian or vegan, because plant sources aren’t absorbed as easily. Better yet, get your blood tested once or twice per year; ask your doc to check your ferritin levels, a measure of iron stored in your tissues (benchmarks vary, but many sports dietitians place the cutoff for low levels at 50 micrograms per liter).

Power Your Pregnancy

Your body needs even more energy to grow a new human, and if you’re running through your pregnancy, it’s more important than ever to ensure you’re eating enough, Minagawa says. Your iron needs roughly double to provide oxygen to your baby—aim for about 27 milligrams. In addition, adequate folate intake prevents birth defects. Good sources include beans, peas, dark green leafy vegetables, and fortified foods, and your doc may recommend a supplement.