Joey Thurman enjoys a scroll-stopping health and fitness challenge. When we connected and he shared that he was about to do a 24-hour Dunkin’ Donuts challenge while wearing a continuous glucose monitor, I said, “I want in.” Thurman, a Chicago-based fitness expert, who’s worked with a wide range of clientele from WWE wrestlers to hedge fund executives, is known for putting his body through self-experiments to better understand what his clients might go through.
“I’m a human guinea pig myself,” he told me. “I like really seeing what happens to my body and how I feel.”
This time, he set out to consume nothing but Dunkin’ Donuts a la carte for an entire day while tracking his blood sugar response. Think sandwiches, wraps, donuts, bacon snacks, and coffee. I jumped in to bring a female perspective to the metabolic madness. Equipped with continuous glucose monitors (CGM) and a food log app, we wanted to see if resistance training, walks, and apple cider vinegar could blunt the damage, or whether the glucose roller coaster would run the show.
What the Numbers Showed
I aimed for roughly 2,000 calories and 100 grams of protein. However, it proved to be a challenge at a chain where donuts and croissants rule the menu. My actual log came in at just under 2,400 calories: about 94 grams of protein, 202 grams of carbs, and 129 grams of fat. Joey went bigger in every sense, consuming 4,500 calories with a much higher protein target. He carries way more muscle mass than I do, so his target made perfect sense.
Klaudia /M&F
My blood sugar started stable sitting at my 85 mg/dL baseline, but it quickly turned into a Six Flags roller coaster ride that never seemed to end. By the time of the challenge I had been wearing the CGM for 10 days, so I knew my normal patterns well. Most meals would spike me to 95-98, hardly ever cracking 100 unless dessert was involved. Yet every single Dunkin’ meal launched me into the triple digits.
Thurman’s levels were slightly different but equally revealing. His glucose was in the triple digits most of the day and even hit 160 mg/dL at one point.
The spikes were just one thing, it was the relentless frequency. To hit our protein goal, Joey and I had to eat five times throughout the day, roughly every three hours. This created a metabolic nightmare where we’d trigger another insulin response before our glucose could even return to baseline from the previous meal. Our pancreases were working overtime, pumping out insulin to deal with waves of refined carbs, never getting a break to let our blood sugar truly stabilize. Be sure to check out his video as he logged the entire day! He even added a control day a day prior to see how Dunkin Donuts would impact his blood sugar without any activity involved.
Why Bioindividuality Matters
The differences between us were interesting and likely rooted in bioindividuality. My blood sugar never soared into extreme highs, but it lingered longer after meals. Thurman explained that might be due to the high fat content. “These are higher fat meals, which slows gastric emptying,” he noted when I described my sluggish glucose clearance.
But the most fascinating difference showed up overnight. My data settled into the 80s mg/dL and stayed steady. Joey’s, on the other hand, had a sharp drop to 73mg/dL at 3:15 a.m., which was a lot lower than at any point throughout the day for him, followed by a rebound spike to 140 mg/dl. All that likely a liver glucose dump that coincided exactly with him waking up.
“I dropped down to 73 [mg/dL] at 3:15 AM, and then at 3:45, it jumped up to 140 [mg/dL],” Joey said, checking his sleep data. “I was awake at 3:48. The exact same time. That’s directly coinciding.” For athletes and lifters who often wrestle with sleep quality, that kind of glucose swing is a reminder of how food choices and meal timing might ripple into recovery.
Calories vs Hunger
What struck us both was hunger. Despite consuming 4,500 calories, Thurman was ravenous. “The hunger was really interesting,” he reflected. “I felt more full than any other day having half the calories.”
I felt the same way, and we were both “hangry” all day.
The culprit, he explained, was likely the lack of fiber on the Dunkin’ menu. On the Dunkin’ day, Joey consumed just 11 grams of fiber, while his average is at least six times that amount. While fat slows gastric emptying, it doesn’t trigger the same satiety signals as fiber-rich foods. We were eating constantly but never feeling truly satisfied.
How Movement Impacted Blood Sugar
From a training perspective, the results were mixed. Thurman enjoyed the pump that comes with carb-loading. He kept his workout simple and accessible. He did three working sets each of back squats, bench press, and cable rows, totaling about 12-15 compound movement sets. “My workout was great. I mean, I’m always vascular, but I was all pumped up, ready to go,” he said.
My experience was different. I tackled a lower-body HIIT circuit. I could still lift, but my legs felt heavy, and the energy swings made it hard to stay focused. By dinner, the bacon-and-donut combos produced what felt like a pharmaceutical yo-yo of energy and brain fog.
Thurman’s post-meal workouts and walks made a dramatic difference, he recalled. In addition to resistance training, he also tracked over 14,000 steps that day. “It stayed pretty much stable the entire time from that walk a few hours beforehand,” he shared. “Movement is the biggest difference maker, and a brisk walk is the fastest, easiest and most effective hack.”
I also give credit to his skeletal muscle acting like a glucose sponge, pulling sugar out of his bloodstream through insulin-independent pathways.
The Practical Takeaways
So what should you take from this metabolic rollercoaster ride?
Walk it off, literally. A walk after meals is a simple but powerful tool. As Thurman put it: “Five to ten minutes after a meal. Do it three times a day. That’s 30 minutes of movement without ‘working out.’ Sesame Street math,” he explained with a smile.
Protein helps, but it’s not a shield when paired with high fat and sugar. We both hit our protein targets but still felt undernourished and glucose spikes were still frequent.
Fiber remains the foundation for satiety and stable energy. The significantly lower levels of fiber than what we both were used to left us hungry the entire day.
Timing matters. Eating too frequently before glucose from the last meal would clear kept our blood sugar levels elevated between meals.
The Mental Game
The psychological component proved as important as the physiological. Thurman’s perspective on planned indulgence versus guilt-driven restriction was particularly insightful: “If you’re going to have a day where you go crazy, be prepared mentally. You need to know yourself and your responses. If you can’t have a cheat day without beating yourself up the next day, don’t.”
He advocates for reframing “cheat days” as strategic refeeds around high-activity periods. “Structure it around a big workout day, like leg day.”
The Bottom Line
You can’t outlift donuts forever. Protein and exercise blunted the glucose spikes, but fat, sugar, and low fiber still dragged our focus, hunger, and recovery.
The data confirmed what we both felt: exercise helps a lot, but it isn’t a free pass. A simple walk after meals can work wonders, but it can’t completely override the metabolic cost of eating like a toddler at a birthday party for an entire day.
Most importantly, this experiment reinforced that sustainable health is about making informed choices and understanding the consequences. Sometimes that means strategically planned indulgence around activity. Sometimes it means walking away from the donut case entirely.
