Sean Kelly is a nutrition-focused social entrepreneur who co-founded HUMAN (Helping Unite Mankind And Nutrition) in 2008. Through customized micro markets, office snack delivery services and vending machines, HUMAN optimizes workplace engagement and delivers on its vision "to make healthy food more convenient than junk food." With more than 2,000 locations across 45 U.S. States, Canada, and Puerto Rico, the "better-for-you" platform delivers a wide variety of healthy snacks, fresh produce, coffees, and locally-sourced foods.

When your team is engaged and having a good experience at work, their creative limits know no bounds. The unfortunate reality, according to Dale Carnegie, is that roughly 71 percent of all employees in the United States are not fully engaged by their jobs. What's even more sobering is that companies with engaged employees outperformed those without by up to 202 percent.

How can you tell if your employees are engaged? It's evident when people go above and beyond their "roles" and are dedicated to advancing the company's goals. It's an office where employees love their jobs and stay for longer than a couple years.

Here are five simple ways you can improve the engagement and culture of your team.

Give Praise and Give It Often

Appreciation is a fundamental need for humans: we crave it from our families, friends and colleagues. Showing gratefulness for someone releases dopamine in that person's brain, which creates feelings of pride and pleasure. Alternatively, a lack of appreciation forces people to find that dopamine "hit" from other sources. A Gallup study found that the number one reason why most Americans quit their jobs is because they do not feel appreciated. When employees are given recognition, they immediately feel that their work is both respected and valued. This increases their confidence and productivity, and motivates them to continue the good work for which they've received praise.

Every Friday afternoon at HUMAN HQ, we gather together to give someone else on the team praise for something they did well during that week. It gives that person some well-deserved appreciation and they get to be recognized in front of the whole team. We call ours the "Crush-It Call," but you can change the name to suit your company's culture. Another way to achieve this sentiment is for managers to write a personal card to employees for events like birthdays and work anniversaries. Be sure to include recognition of good work in these hand-written notes.

Invest in Your Employees' Development

When the managers on your team are committed to the personal and professional growth of each team member, magical things happen. Again, this is a way of showing each team member his or her value to the organization: you're letting people know that you care about their growth within the company as well as outside of it. Some companies may be timid about teaching their employees too much or giving them too many skills, fearing employees will leave; quite the opposite is true. If you provide your team with growth and the ability to expand their knowledge, they'll actually produce more and stay longer. We encourage personal development at our company by paying for professional or personal development courses, books or seminars. Each Monday, we also hold a "Sensei Session" where we use our lunch hour to discuss personal and professional development topics.

Create a Flexible Work Environment

Give your team the freedom to achieve results without focusing on micromanagement or time spent at work. While it's easy to measure time, I've found the most important thing to focus on is developing the metrics and determining what behaviors produce success. Then it's all about measuring those metrics and monitoring the behaviors. Let your team know that as long as they hit their results, it doesn't matter how much time they spend at their desks. If they want to go to the gym or run errands in the middle of the day, give them the flexibility to do so. Always keep the focus on bottom line, not on the time spent at the office.

Connect What You Do With a Higher Purpose

The telltale sign of low engagement at work is when most people are watching the clock, counting down the minutes until they can go home. In order to curb clock-watching and increase engagement, it is imperative to connect what you do with a higher purpose. This is important for any organization, regardless of your business's industry or service. You must know your core values, talk about them and hire by them.

At our company, we require all new hires to take a "Core Value Quiz" that they submit to our Director of Talent Acquisition. We also nominate a "Value Victor" each month, which is a team member who embodied a certain core value.

Provide Perks That Improve the Health of Your Office

It's not just about giving away free stuff; it's about creating an environment where employees love coming to work every day, and feel appreciated and rewarded for helping the company succeed. Corporations like Google, Yahoo! and Facebook are notorious for their perks -- Google is constantly setting the bar higher with their free meals (cooked by a cafeteria chef), $12K in tuition reimbursement and other bonuses. These perks pay off through increased innovation, productivity, low turnover, low sickness rates and high employee satisfaction. While this doesn't necessarily mean that you need to hire an in-house chef or build an office gym, you do need to show employees you care about them and their well-being. Hiring a masseuse for the day, taking a half-day Friday to enjoy an activity together, or offering healthy snacks are all simple rewards to give back to a hard-working team.

If you're able to implement these employee engagement activities consistently, you'll attract and retain the individuals who are dedicated to your organization. It's a big reason why we have been able to successfully pivot and grow our business since I co-founded HUMAN in 2008. My belief is that companies who do not invest in some type of engagement program will fail, especially as millennials begin to dominate the workforce.

Just remember this: it's never too late to work on your engagement tactics, so be proactive in creating an amazing culture.