There could also be other undiagnosed conditions that are making that post-lunch slump worse. If feeling tired after every meal (or all the time) is pretty typical for you, it’s a good idea to speak with your doctor. And here’s Naidoo’s pro tip: “Research suggests that including vinegar7 in carbohydrate-rich meals may improve glycemic control and, subsequently, prevent post-meal fatigue.” In other words, maintaining regular mealtimes can help you stave off those post-meal yawns. “If you’re unsure where to start, focus on adding colorful, fiber-rich, and antioxidant-packed vegetables and fruits to your plate,” says Naidoo. “The added nutrients fend off fatigue, and fiber nourishes the gut, which, in turn, encourages a healthy brain.”