I Tried 12-Hour Fasting For 21 Days — Here Were the 3 Major Changes That Happened to My Body

12-hour fasting is a form of intermittent fasting (IF) also known as 12:12, that many people try for weight loss and health benefits including improved digestion, increased energy, and improved sleep. As a certified personal trainer, I don’t follow a specific diet, but I recently tried the Clean Program, a 21-day detox created by Dr. Alejandro Junger, and one component of the cleanse is the 12-hour fasting window. I found it to be extremely effective. Keep reading to learn more about 12:12 and what benefits I experienced after three weeks.

What Is 12-Hour Fasting?

12:12 is a type of intermittent fasting where you fast for 12 hours, then have a 12-hour eating window. One example could be eating dinner at 8 p.m., and then fasting until you have breakfast at 8 a.m. the following morning. 12:12 is considered to be the easiest type of IF since you’re sleeping for seven to eight hours of it. As a rookie, I have to admit is wasn’t hard to follow at all.

12-Hour Fasting Side Effect: I Felt Extremely Hungry in the Beginning

As suggested by Dr. Junger in his book Clean, I decided to write down my daily meals and how I felt each day on the program. My first three days of notes talk about how terrible I am at making tasty shakes and how hungry I felt when I woke up. Most days, I wake up between 4:45 a.m. and 6:30 a.m. to train clients, work out, and then get to work. Before starting Clean, I would have a bowl of oatmeal for breakfast, and not being able to do this during the cleanse was hard initially.

Around day 10, I began to notice that the extreme feelings of hunger I had experienced were beginning to subside. I won’t say that I didn’t feel an ounce of hunger as I continued the program, but I no longer felt like I was starving. It also helped that I began hacking my shake the night before, adding more fat and protein to hold me over until I broke the fast.

12-Hour Fasting Benefit: I Discovered I Had Bloating Issues

I never considered myself to be a person who experienced bloating, except for on my period, but after doing the 12-hour fast for 21 days, I realized that I do get bloated, especially when I consume too much dairy and grains. The pressure, gas, and cramping I had previously experienced at times in my lower abdomen had finally gone away. As I began to reintroduce these food groups back into my diet to identity triggers, I confirmed that consuming too much dairy and grains irritated both my stomach and skin.

12-Hour Fasting Benefit: I Stopped Mindlessly Snacking

I’m the person who will eat whatever is in my home, whenever. Cocoa Puffs in the kitchen? Definitely eating those. A bag of sweet and salty organic popcorn? Gone in two hours. I also have a habit of eating a meal and then snacking afterward. Not because I’m hungry, but because I’m bored or not in the best of moods. The 12-hour fast helped me notice and reduce this habit, and I’m happy to report that on most days, I’ve eliminated my snacking-just-to-snack habit.

Overall, I found 12:12 to be extremely easy to follow. I completed the Clean Program a month ago, and although I refuse to completely cut out cookie dough ice cream, this is definitely a habit I plan on keeping.