In your purse: almonds

Protein and fiber in almonds can help you power through the afternoon. They’re loaded with calcium, zinc, vitamin E, and immune-boosting alpha-linolenic acid (a precursor to omega-3s), all of which promote optimal brain function.

In the car: water

Dehydration can sap your stamina and cloud your thinking. In fact, experts claim that even 2 percent dehydration interferes with performance. You should drink enough water so that your urine is clear or light yellow. For most people, that’s 8–10 glasses a day.

In the office fridge: raw veggies and hummus

High in fiber, protein, and alpha-linolenic acid, hummus is the perfect snack to have on hand. It’s also a good source of iron, which is critical during an afternoon energy slump (low iron can translate to low energy). Pair it with some raw vegetables for a crunchy, tasty treat.

At your desk: whole fruit,especially apples

Apples are high in fiber and loaded with disease-fighting antioxidants. What’s more, apples contain boron, a mineral that reportedly keeps college sophomores awake during class.

Source: Jonny Bowden, PhD, CNS