Man Who Lost Over 100 Pounds Reveals the 1 Lifestyle Change That Had the Biggest Impact

While earning his doctorate degree, Martin Christiansen turned to food to cope with stress. Now, he's embracing new habits.

Martin Christiansen logs his progress in a spreadsheet so that he can look back at his weight and blood pressure for any given day.

“When I go see my weight loss doctor, I usually have a PowerPoint with me to highlight things I’ve been doing,” Christiansen tells TODAY.com.

But today, he flips through his papers. According to his latest calculations, over the last year, he has lost 2 pounds of muscle and 30 pounds of fat, bringing his total weight loss to more than 100 pounds. And he’s not stopping here.

The Weight of Stress

For most of his adult life, Christiansen’s weight stayed steady around 180 pounds. However, during the final year of his Ph.D. program in 2001, to cope with the pressure of writing his dissertation and 18-hour days focused solely on calculations, he ate.

“My problem really was that I stayed hungry no matter what,” he recalls. “Yeah, I would be hungry after eating food. I would be hungry when my stomach could have no more food in it.”

The now-53-year-old’s preferred haunt was a nearby pizza place he’d go to with his wife, Katie, in their Laurel, Maryland, neighborhood. As he continued to soothe with food, Christiansen found himself at 386 pounds, his highest weight.

Martin Christiansen
Christiansen at First Landing State Park in 2022.Courtesy Martin Christiansen

He tried changing his habits. He started running. “That was a great distraction for me. And I really enjoyed that,” he says.

Christiansen went on to run the Chicago Marathon and kept at the sport until he tore his meniscus, a piece of cartilage in the knee. After two surgeries, running was no longer an option. “That was one of the techniques I was using to try to control my weight,” Christiansen says.

Then came the diets. “I tried all kinds of various diets, as everyone does who is trying to lose weight,” Christiansen says. His technique, however, was uniquely him.

The mechanical engineer approached weight loss much like he approaches many things in life. “I’m a researcher. So, this stuff all comes with (peer-reviewed research) papers and other things,” he explains.

His data-backed approach led Christiansen to diets that had him eating more meat, then less meat, then vegetables, then different vegetables, until he found the Greger Diet, founded by physician Dr. Michael Greger, in 2020.

“It’s a diet that minimizes the intake of meat, eggs, dairy and processed junk, and maximizes the intake of fruits, vegetables, legumes like beans, whole grains, nuts and seeds, mushrooms — basically, real food that grows out of the ground. Those are our healthiest choices,” Greger previously told TODAY.com.

While on the diet, at one point, Christiansen lost 38 pounds, but his weight fluctuated over the next three years. He stuck with it until November 2023, when he found the program that made the biggest change.

A Promising Program

“My primary care doctor suggested it,” Christiansen recalls. At the time, he was 351.9 pounds, and she suggested he enroll in The Johns Hopkins Healthful Eating, Activity & Weight Program, which counsels patients looking to achieve healthier lifestyles and manage chronic disease.

He met with a physician who assessed his diet and fitness practices, and together they customized a plan for a new weight loss process. Every month, he’d meet with his doctor to check in.

Like with most things, Christiansen made the process his own.

“I constantly make the joke I’m an engineer. There is no cure, (but) if there’s data, I will calculate. You know, I’m probably the only person who I know that has a linear regression of my weight loss. And people say weight loss is highly erratic. I’m like, ‘mine’s linear.’”

Since Christiansen already had a consistent walking routine — his peak is 60 miles in one week — the plan was to continue doing it. He also added weightlifting with a physical therapist and woodworking with heavy construction materials to his weekly rotation.

Men standing in new york city with his wife.
In one day, Christiansen and his wife, Katie, might walk up to 18 miles during their trips to New York City. Here, they're at the downtown walking path they're fond of.Courtesy Martin Christiansen

Doctors also prescribed him a weight loss pill. And for the first time in a long time, after one slice of pizza, Christiansen was full. Soon after, his doctor replaced that pill with a prescription for Mounjaro, sometimes referred to by its active ingredient, tirzepatide. It’s FDA approved to treat Type 2 diabetes.

It works by activating receptors in the brain for two hormones, GIP and GLP-1, which are produced after eating. This leads to decreased appetite and food intake, TODAY.com previously reported.

Along with his Mounjaro injections, Christiansen had to fit movement into his daily schedule and make dietary changes, including increasing his protein intake.

“I didn’t just go to fast food and eat hamburgers,” he says. He stocked his fridge with smoked salmon, beef from a local farm and dough he made himself for thin-crust pizzas and pizza pockets filled with vegetables and minimal cheese.

Christiansen stands with the cutting board he made for his parents this year.
Christiansen stands with the cutting board he made for his parents this year.Courtesy Martin Christiansen

Christiansen compared his weight loss progress to that of participants observed in clinical studies. Though his doctor increased his dosage at a slower rate than researchers did with their trial patients, “I’m right on the line,” he says.

Today, Christiansen is still losing weight while taking 15 milligrams of Mounjaro, the highest dose. “The last time I saw my weight loss doctor, where I updated him on all the things, I was losing point eight pounds per week, which is still a pretty steep clip,” he says.

What the Future Holds

Of his many woodworking projects, Christiansen has completed two side tables made from Cherry wood, cutting boards and a bench made of Baltic birch. Now, he’s working on a dresser.

“I try to do something every day,” Christiansen says about his fitness routine. With rare exceptions — French fries in particular — Christiansen’s diet is focused on whole foods. His blood pressure has returned to a normal range, and he’s more than 100 pounds down, a 26% reduction by his calculations.

Christiansen and his wife, Katie, happened upon this flowerbed during one of their 15-mile walks in New York earlier this year.
Christiansen and his wife, Katie, happened upon this flowerbed during one of their 15-mile walks in New York earlier this year.Courtesy Martin Christiansen

At 275.5 pounds, he’s got more weight to lose, but Christiansen says he doesn’t have a goal. “I’m going to do my best,” he adds.

“People used to ask what it takes you to get a Ph.D.,” says Christiansen. “There are only two things you need. ... You need to want it, and you need to want it every day.'”