Gorske claims that after getting his first car, the first place he went to was a McDonald's on May 17, 1972. He purchased and ate three Big Macs at lunch time. He then returned two more times that day to consume a total of nine Big Macs the same day he discovered the burger. He further claims to have eaten 265 Big Macs in the following month, an average of 8.5 Big Macs per day. If true, this would be equivalent to over 4,600 calories and 247 grams of fat daily, for a total of 143,100 calories and 16.9 pounds of fat in one month. He also claims to drink almost nothing but Coca-Cola and, according to Super Size Me, he rarely eats the fries. At first, Don kept all the boxes of Big Macs he ate in the back of his car. He met and proposed to his wife, Mary, at a McDonald's in 1973. In addition, he has a statue of Ronald McDonald in his yard. Gorske also states that he has only eaten one Burger King Whopper sandwich in his life in 1984, and will never eat one again. Gorske claimed that he first tried a Whopper after his friend bet him $5 to do so, and that he then spent the money on Big Macs.
In 2003, Don Gorske ate 741 Big Macs, an average of 2.03 Big Macs per day. Gorske is 6 foot 2 inches tall (1.88m), 185 pounds (83 kg), and claims a cholesterol level of 140. His claimed average daily consumption of two Big Macs amounts to 1,080 calories, according to the nutritional information published by McDonald's; this does not take into account his energy intake from fluids. The USDA recommends about 2,200 calories per day. Gorske consumes mainly calorie-rich food, but he maintains a stable weight by consuming fewer calories daily than the average American. He says his taste buds have always fluctuated in sensitivity, so he often eats a Big Mac without being able to taste it.
On May 17, 2011, Gorske ate his 25,000th Big Mac at his favorite McDonald's restaurant in Fond du Lac. On his birthdays he puts candles in Big Mac like a cake and when Christmas time comes around he treats himself to more Big Macs while his family have more traditional Christmas food. He claims that since he ate his first Big Mac, there have only been eight separate days in which he did not eat a single Big Mac. One of these days was the day his mother died, and he did not eat a Big Mac to respect her request. Other days included a "Snow Day" when McDonald's was unable to open due to snow, a Thanksgiving, days he was traveling and could not find a McDonald's, and various days Gorske had to stay at work past midnight. Gorske has since started keeping an "emergency stash" of Big Macs in his freezer for emergencies and snow days. Don Gorske also records when and where he eats his Big Macs in a notebook that he always carries. Gorske has kept every burger receipt in a box.
Gorske claims to have eaten 25,000 Big Macs as of May 17, 2011, and ate his 29,000th Big Mac on December 8, 2016. He also maintains that he has no (known) health issues and has not had reason to visit a doctor. At his doctor visit on April 26, 2011, his first since 1985, his cholesterol level was 156 mg/dl, which is below the average of 208 mg/dl.
Gorske worked as a correctional officer at Waupun Correctional Institution for 25 years. He retired in May 2011.
He appeared in the documentary Super Size Me. In the DVD extras for the film, it is revealed he works as a correctional officer. He also makes a cameo appearance in cartoon form in the film.
In 2006, Gorske appeared as a contestant on the game show I've Got a Secret. Celebrity panelist Billy Bean was able to guess the Big Mac as Gorske's food of choice.
On May 25, 2009, Gorske was featured on The Rachael Ray Show.
To congratulate Gorske on eating his 25,000th Big Mac, he appeared on The Kyle & Jackie O Show on May 20, 2011 and Lopez Tonight on May 23, 2011.