Dad loses 100 pounds in 6 months after seeing photo of himself sleeping in church

A dad of two from Texas is celebrating a 100-pound weight loss that he says was inspired by a photo of him taken by his wife.

The photo showed Jamie Wooldridge, of Southlake, Texas, sleeping while sitting on a pew inside a church.

"The photo was not flattering at all," Wooldridge told "Good Morning America." "It was like, OK, I need to do something about this."

After seeing that photo of himself and recognizing that his overall health -- including his cholesterol and blood pressure levels -- was suffering, Wooldridge started a weight loss journey that he said helped him lose 100 pounds within six months.

His first step towards weight loss was to begin counting the calories he consumed using an app on his phone.

"I was shocked to see that I was probably consuming 4,000 to 5,000 calories a day," he said. "It was humbling."

Wooldridge said he figured out that for his age and activity level he should be consuming around 3,300 calories per day to maintain his weight. He said he began eating around 1,000 calories less than that, around 2,200 calories per day, in order to lose weight.

He said he cut down his calories without cutting out his favorite foods, like pizza, explaining, "If I'm going to have pizza, well I'm just going to budget that into my calorie allotment for the day." (Experts advise those looking to make major changes to their diet to consult with a medical professional.)

Wooldridge also decreased his processed sugar intake and cooked with an air fryer to lower the fat content in some of his favorite foods, like French fries.

He said he learned to plan ahead so that he could stay consistent with his eating even while celebrating things like birthdays or eating meals at restaurants.

"Every month there’s going to be something," he said. "There's so many tools out there that can help you be successful."

When it came to getting active, Wooldridge said he continued his daily habit of walking several miles, and gradually increased the intensity to running.

His advice to sticking with diet and exercise goals, he said, is to "make your resolution your routine."

Dr. Veronica R. Johnson, an obesity medicine physician and assistant professor at Northwestern University Feinberg School of Medicine, emphasized that anyone making significant changes to their diet should consult with a health care provider.

Johnson, who did not treat Wooldridge, said that while most people may not lose such a significant amount of weight in a short timeframe, any weight lost can improve a person's health.

"It's sometimes not as easy for patients to lose weight using lifestyle alone," Johnson told "GMA." "So, if you really want to get to an overall, healthy weight and you're struggling, seeking out a health care professional to help you on your journey is really important."

In addition to talking with a health care provider, an online resource for people looking to make healthy changes is MyPlate.gov, a U.S. Department of Agriculture website that offers tools like a calculator to determine your daily caloric needs.