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

Twelve-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.

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., 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 it wasn't hard to follow at all.

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 the Clean Program, 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.

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 identify triggers, I confirmed that consuming too much dairy and grains irritated both my stomach and skin.

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.