March 17, 2026, 1:24 p.m. ET
- Matt Kaestner changed to a plant-based diet after being diagnosed with Type 2 diabetes.
- A staple at 5K races in Central Massachusetts, Kaestner plans to run his first marathon in May.
- He hopes that by talking about his weight loss journey, he can inspire others.
SHREWSBURY – “Wake up, big man.”
Matt Kaestner heard those words while he was lying on the bench at the gym. He had fallen asleep for 10 minutes and didn’t even know, a scary situation. A few other health scares popped up over the next few months, and he found himself constantly tired and struggling to accomplish basic tasks.
Eventually he went to the doctor, where he found out he had Type 2 diabetes.
“The [doctor] looked at my bloodwork and she said that I should be in the hospital, and that scared me,” Kaestner said.
Kaestner, 48, has always been big – he weighed over 11 pounds at birth and was a star football player at Assabet Valley Technical High School, playing on the offensive and defensive lines. However, in later years his weight continued to climb upward, all the way up to 510 pounds.
“When I look back on it and see old pictures of myself, I can’t really believe I was ever that big,” Kaestner said. “You don’t realize that is happening in real time.”
A life-changing diagnosis
Type 2 diabetes can cause blood sugar to build up in the body, disrupting a person’s natural hunger cues. Kaestner said he recalled eating excessively, including multiple pizzas but still not feeling satisfied.
“I think a lot of people would have a better understanding about why people might be overweight if they better understood what diabetes does to the body,” Kaestner said. “People see someone and they think that they are just lazy, but for me, my body was literally telling me to eat when I didn’t need to.”
The diagnosis helped change things for Kaestner. He received treatment for his diabetes and made the switch to a plant-based diet, in part because he saw a documentary, “The Game Changers,” on Netflix, which focuses on elite athletes who follow such diets.
“My wife was already doing the plant-based diet, so I started doing it and I noticed some changes right away, I had more energy and I dropped about 25 pounds,” Kaestner said.
Kaestner began the process in 2020, and today he said he weighs just a bit under 300 pounds, after losing more than 200 pounds. Kaestner said he has always been active, and even at his heaviest he was regularly going to the gym and exercising, but his diet was restricting him from getting healthier.
“I would go to Orangetheory Fitness and do a high-intensity workout, but I just kept getting bigger,” Kaestner said. “It was really just about what I was eating. I’d burn 1,000 calories and then go eat 3,000 calories.”
Today Kaestner said he is primarily on a vegan diet, although he said he does occasionally allow himself to eat a hot dog or a slice of pizza as a cheat meal. He and his wife, Joleen Kaestner, grow their own vegetables in their garden behind their Shrewsbury home.
“We started with just the basics, tomatoes and cucumbers, and over time we’ve added more stuff: Broccoli, lettuce, onions and peppers,” he said.
Embracing the running lifestyle
Running has been a huge influence on his weight loss.
“I always wanted to get into running and when I first started it was just too much. So I started with walking, then I slowly transitioned into light jogging and then finally running,” he said.
Matt Kaestner found a home with the Central Mass Striders running club and at Sneakerama, the Lake Street shoe store that hosts weekly fun runs Thursday nights in Worcester. Over the past few years he has been a staple at the weekly runs, both as a participant and as a volunteer who helps runners cross the street.
“When I stand in the crosswalk with a stop sign, people stop,” Matt Kaestner, who stands 6-feet 2-inches tall and previously worked as as a correction officer for the Worcester County Sheriff’s Office, said with a laugh. “The people at Sneakerama and Central Mass Striders have been extremely supportive of me as I’ve gone on this journey, telling me constantly that I can do this.”
He is also a staple at community 5K races in the area and has run the Falmouth Road Race the last several years, representing the Cape and Islands Veterans Outreach Center. He will be running in his first half marathon in Providence in May and said that he has an ultimate goal of running in the Boston Marathon.
“Just to be able to cross that finish line and say that I did it – I don’t care if it takes me six hours – I could run it,” Matt Kaestner said. “I’d need to be able to get the fundraising goal, which is really difficult, but I would love to be able to do it. People used to laugh at me even when I was a kid when I said I wanted to run the Boston Marathon and to cross that finish line, that would be incredible.”
Sharing his story
A realtor with Century 21, Matt Kaestner has labeled himself “The Running Realtor.” He runs a Facebook and Instagram page documenting his career and his running.
He said that while most people in his life have been very supportive of his weight loss, there have been some relationships he said he had to end.
“I had people who questioned my diet, who did not want to support my lifestyle change,” he said. “I realized those people were really not my friends. I’m still the same me, I just eat differently now.”
Matt Kaestner said his weight-loss journey has not always been easy. He has dealt with some lingering physical issues and at one point in 2024, he gained 80 pounds, but he said he is happy with where he is at today.
“I think maybe I’d like to get down to 250 pounds. That would be a reasonable goal. I know how difficult it can be, but I am determined to never go back up again,” he said.
His wife said people don’t even recognize him anymore.
“I am so proud of him and when people see him for the first time in a while, they will tell me how great Matt looks and that they can’t believe it is him,” Joleen Kaestner said.
A lifelong Shrewsbury resident, Matt Kaestner said he doesn’t want to preach to anyone about how to get in better health, but he hopes that by talking about his journey he can have a positive impact on other people.
“I am not going to be slapping a burger out of anyone’s hands. I know what works for me and what might work for someone else could be entirely different,” he said. “I think that if one person can hear about my story and it helps them with their weight loss, that would be amazing.”