Days packed with meetings, deadlines, and errands leave little time for lunch, so you run out for a slice of pizza and keep powering through the afternoon. Soon, you’re hungry again, drowsy, and a little too cranky to focus on your boss’ PowerPoint. You just steered yourself straight into a sugar crash that brought on a post-lunch slump. The processed grains in your pizza crust or sandwich’s white bread are stripped of their most nutritious parts, the bran and the germ. These simple, high-glycemic-index carbohydrates energize you quickly with a spike to your blood sugar that suddenly drops to leave you lethargic and a bit brain foggy.

Feel more vibrant by fueling your afternoon with whole grains, fruits, and vegetables as well as healthy fats (avocado, nuts, seeds, and olives) and plant-based proteins (beans, tofu and lentils) that keep you satisfied and sustain energy. Complex carbs like unprocessed grains, fruits, and vegetables are filled with fiber so they are high on the glycemic index. That means they are slower to digest and keep your blood sugar stable, aka no after-nosh crash that makes it hard to focus. All that fiber helps you feel fuller longer and avoid cravings so soon after the lunch hour.

Get even more bang for your nutritional buck by choosing sprouted grains, which boast increased amounts of vitamins (antioxidants in particular) and minerals that are more easily absorbed than nutrients found in regular whole grains. Breads made from sprouted grains are also easier to digest thanks to the enzymes they retain, so you don’t feel as tired or bloated after eating them. Even better: Compared with non-sprouted whole grains, the sprouted variety contains more fiber and has less of an impact on your blood sugar levels.

Thinking you don’t have time to pack a healthy lunch at night or in the a.m.? Just bring a few ingredients that you can turn into your midday meal in the time it takes to grab an empty-calorie lunch from a deli.