"How can a woman approaching middle age get more energy?"

Many women start to feel like they're dragging in their late 30s and 40s. They're losing testosterone, which may act as an antidepressant, and experiencing a flux in their levels of estrogen and progesterone, which may also influence mood and energy. One of the most effective tactics for perking up comes down to how you plan your meals. "Many of my clients seem to think that by filling one meal with energy-generating nutrients—say, a green smoothie for breakfast or a salad at lunch—they've done their duty for the day," says dietitian Ashley Koff. "But your body needs several energy pit stops so you can refuel." Koff suggests small meals every three hours that combine a variety of nutrients. Her energy-boosting meal plan:

Breakfast: Oatmeal with hempseeds.

A.M. snack: Half cup of cottage cheese with berries.

Lunch: Half a turkey sandwich with salad.

P.M. snack: Half cup of tuna salad with wheat crackers.

Dinner: Wild salmon with non-starchy veggies.