Here’s a scenario for you: You’re at work, it’s 2 p.m., and even though it’s been a few hours since you’ve had lunch, all you want to do is go home and take a nap. If you’ve experienced this at some time or another at work, then you should probably keep reading.

When people think of health and fitness, they usually think of how it will affect their lives in terms of looking good in that new swimsuit in time for their vacation, or not getting short of breath when walking up three flights of stairs to their apartment while carrying two bags of groceries. How your health and fitness affects your work performance is rarely considered, despite the fact that it can have a great impact on your productivity at your job.

Will Mitchell, an entrepreneur-turned-professional-athlete-turned-entrepreneur, knows just how important it is to stay fit and healthy, whether you’re spending the majority of your time on the field or at a desk. “After my return to entrepreneurship, I went from peak physical shape to a complete slob (telling myself diet and exercise would somehow hurt my productivity),” he says. “My work performance tanked as a result, and it took me a long time to accept that diet and exercise were the reason why.” Like Mitchell, there are many experts who agree that diet and exercise play an important role in workplace performance, as well as your overall performance in pretty much any area of life.

So what should you eat while at work? Lori Langer, a registered dietitian, has some suggestions. “Have a little protein with each meal and snack to keep your glucose curve from taking major swings,” she says. “Nuts, seeds, or dairy with some fruit make great snacks.” She also suggests staying away from sugary foods, energy drinks, and a lot of caffeine.

Coffee addicts, don’t panic. You don’t have to cut coffee out of your life forever, but it may be a good idea to slowly cut back. For your body to run at peak performance daily, Langer says you should “consume whole foods such as fruits, veggies, lean meats, dairy, and whole grains. Avoid processed foods, anything that comes in a box, and contains more than a few ingredients.” In addition to eating healthier, she says “exercise, in any form, will increase energy levels. Many state they don't have time for exercise, but it will pay off by making you more productive.”

If you haven’t hit the gym in a while, and really have little time to do so, there’s no need to worry. Sometimes, being healthy is as simple as staying hydrated, which is the key to being productive in the workplace, according to Christina Chambers, a natural health and wellness expert. She says, “Dehydration has been linked to the dreaded afternoon slump and affects both mental and physical performance.”

Langer agrees. “Dehydration can lead to headaches, lower back pain, and other ailments that limit productivity,” she says.

So, when you get home from work today, perhaps you should ditch the after-work routine of sitting on the couch and watching television, and consider doing a bit of cardio and preparing yourself a healthy lunch for tomorrow. Especially since doing these little things could make a big difference on how well you do at your job, as well as how you look in your new swimsuit.

“A nutrient-deficient mind will create nutrient-deficient thought,” says Mitchell, “and anybody who says otherwise isn't pushing themselves to their full potential.”