"I was out of shape, living on fast food and not exercising," he wrote on his website.

That year, his father died, and his physical and mental health reached rock bottom. But after a friend suggested he try running to ease his depression, he started making gradual lifestyle changes, taking up more exercise and eating better.

By 53, Maroon had signed up for his first Ironman Triathlon and has since completed eight in total. Maroon came in second in his age category for the 2022 National Senior Games triathlon.

Maroon previously shared with BI how he was staying fit, and his diet principles are explained below.

Follow a Mediterranean-style diet

Maroon says he follows the Mediterranean diet, which US News & World Report has said for seven years in a row is the best way to eat.

It's not a "diet" in the way you may think, but more a way of eating that centers on healthy choices rather than restriction.

It's mostly plant-based and focuses on whole foods, including fruits, vegetables, whole grains, beans, legumes, and healthy fats such as olive oil. It includes some fatty fish and red meat on occasion.

The diet has been linked to a multitude of health benefits, including a lower risk of heart disease, cancer, and Alzheimer's disease.

Avoid ultra-processed food

Ultra-processed foods, or UPFs, are made using techniques that are difficult to recreate at home and may include additives such as salts, sugars, and saturated fats, according to the Nova scale, which categorizes foods by how processed they are.

An easy way to tell whether something is ultra-processed is if it doesn't look like its ingredients — such as protein bars or hot dogs.

UPFs have been linked to an increased risk of illnesses, including cancer, dementia, and cardiovascular disease.

Avoid trans fatty acids

Trans fats can increase levels of "bad" low-density-lipoprotein cholesterol in the blood while decreasing levels of "good" high-density-lipoprotein cholesterol, which can increase the risk of heart disease and stroke, as Dana Ellis Hunnes, a senior dietitian at UCLA Medical Center, previously told BI.

Artificial trans fats are made by hydrogenating vegetable oil. They were commonly found in packaged UPFs until the FDA declared trans fats unsafe to eat in 2015. The FDA gave food manufacturers three years to remove trans fats from their products, so most foods no longer contain them.

But foods can still legally contain under 0.5 grams of trans fats, as Kristin Gillespie, a registered dietitian, previously told BI, so it can be worth watching out for them. They typically appear in ingredient lists as "partially hydrogenated" oil in foods such as margarine, premade pie crust, non-dairy coffee creamer, and packaged baked goods.

Eat less sugar

The healthiest diet involves "avoiding a whole lot of things that people like to eat," Maroon says, including sugar.

Heidi Tissenbaum,a professor in molecular, cell, and cancer biology at the University of Massachusetts Chan Medical School, previously told BI that in her research, removing added sugar from the diet of roundworms, which are used to model the human health span, was linked to increased longevity. It's theorized that this is because when the body metabolizes sugar, it produces by-products associated with an increased risk of diabetes, cardiovascular disease, chronic kidney disease, and Alzheimer's disease.

She said it was also important to keep blood-sugar levels stable to prevent wearing out the mechanism the pancreas uses to regulate spikes, which could increase the risk of developing type 2 diabetes.

Avoiding UPFs, which tend to be high in added sugar, can help with this because eating more fiber-filled whole foods helps regulate blood-sugar levels.