Grist is proud to present the Change Gang — profiles of people who are leading change on the ground toward a more sustainable society and a greener planet. Some we’ve written about before; some are new to our pages. Some you’ll have heard of; most you probably won’t. Know someone we should add to the Change Gang? Tell us why.

It doesn’t take Corey Rennell more than a few staccato sentences to explain why, as a kid growing up in Alaska, he first started taking his food seriously.

“My mom was a huge hippie and only fed me natural food. My dad was a hunter. I watched Bambi when I was 7, and then shortly after, my dad killed a deer and served venison as my first taste of red meat. I was confused as to what it was. He said it was deer — baby deer. I had a meltdown and became a vegetarian.”

Today, after some detours that would defy the imagination of even the most baroque novelist — body builder, mountaineer, reality TV show contestant, Harvard graduate — the 26-year-old Rennell is the founder and owner of Core Foods, a San Francisco-headquartered food company that makes what are perhaps best described as ultra-natural energy bars.

Rennell’s “Core Meals” are so natural, in fact, that you won’t be able to find them on the same shelf with the Clif Bars or the Power Bars. These mixtures of nuts and fruit and other natural ingredients — no flour, no sweeteners, no oils — are perishable; they must be refrigerated.

“No bar that you ever eat of mine is ever a month from when I made it,” says Rennell, who is convinced that freshness is critical to maximizing the nutritional benefits from food.

That may not be the most earthshaking theory ever propounded by a Bay Area food activist, but Rennell has pushed his convictions further than most. He isn’t just trying to provide an alternative energy bar; he wants to shake up the whole for-profit food business.

Rennell believes that the economic incentives that put a priority on what he calls “shelf-stable” food have created a nutritional catastrophe. The necessity of loading up food with additives and preservatives and sweeteners all hinges on being able to keep that food hanging around as long possible before it must be sold.

“People aren’t eating fresh fruits and vegetables because we’ve tied up food with profit,” says Rennell. “Food is a business, and for businesses there is nothing worse than a perishable inventory. Your profit margin for an entire year can evaporate overnight if a cooler goes out. So grocery stores prioritize shelf-stable food, which means that all the advertising budget for food goes to shelf-stable food, and the only access consumers have is shelf-stable food.”

Core Foods operates on a unique model. Executive salaries are capped, and all profits get poured back into the business.

“At the end of every year, we don’t take a profit on the food,” says Rennell. “We either lower the price to the consumer or we increase the quality of the ingredients to match the profit that we have as a company. Or we do additional things like increase the sustainability of our packaging or make our employees happier.”

“It was really important to me that we didn’t reconnect food with profit,” adds Rennell. “Because otherwise there is an incentive to lower the quality of the ingredients in the food because it increases the profit margin. And that is a very bad incentive for a healthy food system.”

Rennell’s Core Meal recipes are based on insights he learned while competing in Last Man Standing — a BBC-Discovery Channel joint venture reality TV show that plopped six extreme athletes into the midst of 12 “primitive” tribes all around the world. At the time, Rennell was the president of the Harvard Ski Club and had recently participated in a mountaineering expedition to Kyrgyzstan. He took his nutrition very seriously — and he needed to, in order to survive the rigors of Last Man Standing. But his home-brewed mixtures of raw nuts, whole oats, and whey protein “tasted awful.”

“As I traveled to the different tribes,” he explains, “I got some of them to help me with recipe creation. So actually each one of our bars is inspired loosely by recipes that are traditionally based, that feature the traditional flavors of each region.”

And there you have it: a reality-show contestant who takes his nutritional cues from the indigenous inhabitants of Papua New Guinea and India’s Nagaland plans to overthrow the for-profit model of the food industry while helping us all live healthier lives.

It’s hard not to root for the guy.