It's one of the most popular New Year's resolutions (and life-long quests, really): Become healthier, fitter, and leaner.

Six of the ten "how-to" questions that saw the biggest spike in Google searches at the start of the year were about how to cook healthy food. For example, "How to make kale chips" and "how to steam broccoli" both made the list. 

But making kale chips in the luxury of your own home is easy, compared with facing down the temptation you'll face to blow your diet when you have to stay late at the office. Here are some tips from nutritionists, dieticians, and productivity experts on how to eat healthy during a busy work day (and even become more efficient in the process). 

1. Take a proper lunch break.

No matter how busy you are, don't put off lunch so you can send another email. Not only are people who take a leisurely lunch away from their desk  more positive and more creative, they're also fitter. A study published in the British Medical Journal found that men and women who scarf down their food are 84 percent and 50 percent more likely, respectively, to be overweight than their slow-eating counterparts.

If your office frowns upon taking lunch away from your desk, then step outside to take a 5-10 minute walk a few times a day. Kimberly Elsbach, a professor at the University of California, Davis who studies workplace psychology, tells NPR that the first step is managers and employees should take is to "create a culture" around taking lunch breaks. 

"Set up an online forum where you say, 'OK, these are the different activities we're doing,'" Elsbach says. "'There's one group that's going to meet and eat sack lunch outside. There's another group that's going to go for a walk.'"

2. Stock your desk with healthy snacks.

The hungrier you are when you leave work, the more likely you are to grab takeout on the way home. So no matter how busy you are, you shouldn't go hours without eating. In addition, you're likely to be more productive if you snack throughout the day than if you eat large, infrequent meals. The body is better able to maintain glucose levels, so you don't experience the headaches and impaired memory that follow too much of a drop in blood sugar. 

The best way to ensure that your blood sugar levels don't get too low, especially when you have trouble fitting in a break, is to keep a variety of healthy snacks at your desk. Dietician Sarah Romotsky tells The Muse that the best office snacks are ones that contain a mix of complex carbs, protein, and fat, such as trail mix or Greek yogurt with granola. And workplace productivity author Ron Friedman even suggests setting up an automated subscription service to refill your snacks when you're running low. 

3. Keep a full water bottle at your desk.

While it's a commonly held belief, there's no concrete evidence that drinking more water makes you lose weight, nut it does help you avoid overeating, according to nutritionists. Staying properly hydrated also makes both men and women feel more optimistic and less stressed out, according to two studies conducted by researchers at the University of Connecticut. 

To remember to take a break, get up, and get a drink of water while in the middle of a time-consuming project, writer Jenna M. Uszenski on career advice website Levo League suggests setting calendar reminders during the work day. There are also apps that track how much water you drink like Waterlogged, which will send you alerts so you can tell if you're dehydrated.