After Realizing My Weight Put Me At Risk For COVID Complications, I Started Intermittent Fasting and Lost 115 Pounds

By Duane Pretzer, as told to Emily Shiffer


My name is Duane Pretzer, and I am 48 years old. I am from Warren, Michigan, and I work in Corporate Security Management.

At 46, I weighed 300 pounds when I began intermittent fasting with Zero in February 2020. But truthfully, I had been larger than this before. At that time, the Coronavirus pandemic was getting serious. I looked at my current  state of health and realized I had some of the risk factors associated with COVID-related complications. I needed to give myself a fighting chance if I were to get COVID.  

Before I started fasting, I was not disciplined with what I ate, how much I ate, or at what time I ate. I would start my eating and drinking window with coffee creamers and/or high carb foods. I would typically end my day with high carb foods including desserts.   

My goals when I started fasting included weight loss, inflammation reduction, cellular repair, and overall improved health. A friend of mine was using Zero at the time, and they liked how interactive it was, so I decided to give it a try.

I started with the 16:8 time-restricted feeding (TRF) for the first month and lost 15 pounds. While I know this is not necessarily typical for most, it was my clue that intermittent fasting was working for me. When I first started fasting, I felt sluggish and tired. Looking back, I think it was because I was eliminating so many carbs and sugars from my eating protocol. After this ‘detox’ period that lasted about 2-3 weeks, my food cravings started to go away. When I became fat adapted (approximately 1 month), IF became fairly easy for me. 

My favorite feature in the Zero app is the timer, which assists me during my very busy daily life. It takes the guesswork out of when I start and when I can end a fast. It lets me know what Fasting Zone I’m currently in. I also love the statistics feature, which breaks down recent fasts (such as average and length, etc.) 

When I started fasting, I used the Zero app to keep me accountable for when I ate. I used it to change up what I ate and how much I ate. I became more of a mindful eater. My dietary goals were to have foods high in lean protein, good fats and low carbs. I never break my fast with carbs or sugar and never end my eating window with carbs or sugar. This allows me to get into my desired Fasting Zones of fat burning and ketosis quicker during my fasting window. I also stay in a calorie deficit, averaging around 1,800 calories per day.

Here’s what I eat in a day now:

Breakfast: Black coffee and water (typically still in my fasting period) 

Lunch: Lean Proteins such as turkey sausage or bacon, salmon patties, hard boiled eggs, avocado, and cottage cheese   

Dinner: Lean proteins such as ground bison/buffalo meat, ground turkey, grilled chicken, or un-breaded shrimp. I also eat various types of vegetables and salads such as broccoli, green cabbage, kale, Brussels sprouts, asparagus. Instead of pasta or rice, I have Palmini or riced cauliflower. I also enjoy spaghetti squash with meals. 

Snacks: Beef and turkey Chomp Sticks, Quest protein bars, pistachios, bananas 

Dessert: Homemade peanut butter, honey, and oat balls  

I also eliminated cooking with butter and now cook mostly with extra virgin olive oil or avocado oil and sometimes ghee to add flavor to my foods. My favorite meal to break my fast with now is a healthy skillet: 2 eggs, grilled onions, green and red peppers, turkey sausage and bacon, feta cheese, topped with avocado and tomato. 

When I began my IF journey at the start of COVID, it was hard to introduce exercise in the typical sense as no gyms were open. Instead, I incorporated outside and inside workouts with my Apple Fitness Health app. I walked a lot, and I also participated in my first ever virtual 5k. I set my exercise window to occur late into my fasting time period (example: If I was doing a 20:4 TRF, I would exercise at the 18-hour mark of my fast, as I was typically in the fat burning or ketosis stage already). I have plenty of energy during those stages, and it motivates me knowing I’m really helping to burn fat, tone and build muscle. 

I have lost 115 pounds, and my current weight is 185 pounds. I went from a size 3XL to large in shirts, and my waist went from a size 52 to 38. 

Now that I am in a maintenance phase, my protocol is typically 16:8 TRF. At the start of each month, I will do a 48-hour fast to reset my system. I love the flexibility IF allows as a working professional, husband, and dad. During my first year of IF, I averaged 19.5 hours a day fasting. 

I have more energy, get better sleep (I no longer struggle with sleep apnea), have reduced my inflammation, and have had improvements in my metabolic blood panels. I’ve been told by many I look 10 years younger and that I have added some years back on my life. Besides physical benefits, I’ve also experienced mental benefits. I have much more mental clarity and emotional confidence. Overall, I have a more positive outlook on life.

I began my intermittent fasting journey with Zero with the primary goals being weight loss, inflammation reduction, cellular repair, and overall (metabolic) improved health. I have achieved all four of these goals in one year. For the first time in my life, I feel like I have found something that works for me and it’s sustainable. It feels like a lifestyle to me and not just a diet that I’m punishing myself with. Becoming healthy is now fun and inspiring. 


Posted in Member Spotlight


  • Wow.. great testimony to meeting his goal and to Zero App.
    I was not aware of the caloric , or haven’t paid attention to the caloric total he should eat and to the food plan in Zero.

    Thank you for sharing his journey.

  • Well done, you are a star, so very well done, congratulations; you really have reason to be humbly proud.

  • This is a very inspiring story. Thank you for sharing. I have been on and off with fasting and not overly pleased with weight loss. What you pointed out is the need to cut back on carbs and processed sugary junk. Thanks again.

  • Wow amazing journey, thank you for sharing and congratulations, hard work paid off!!

    This is very inspiring, I’m on a very similar journey for very similar reasons, and it gets difficult, but seeing your results definitely helps.

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