Find out what happens to your body after 30 days of alternate-day fasting.
But you don’t have to do it to figure out what could happen, or how your body would react and how you would look. Take into consideration what happened to Brendan Jones, from the YouTube channel the Goal Guys.
The Goal Guys are two brothers (Brendan and Cam Jones) with a YouTube channel with more than 400,000 subscribers. They share videos in which they take on “different goals in fitness and productivity.”
Brendan decided to try alternate-day fasting, which is a type of intermittent fasting where you eat normally on one day, and fast for the following day. In practice, this is your fasting and feeding windows:
- Eat for 12 hours
- Fast for the following 36 hours
- Repeat steps over and over until the fast is complete
Brendan did that for 30 days. And this is what happened.

What Happens To Your Body After 30 Days of Alternate Day Fasting?
According to Brendan, in his research, people who did alternate-day fasting saw greater fat loss compared to a controlled group who did traditional calorie-restricted diets.
Brendan did a scan of his body to find out his body fat percentage and lean muscle mass to see if anything changed for better or worse.
It is important to note that Brendan continued his strength training and running program while fasting, but pushed it harder on the days he was eating as he figured he wouldn’t have as much energy on the days he was fasting.

Brendan’s numbers on the scan were:
- Body fat percentage – 28%
After 30 days, he lost 14 pounds, going from 170 pounds to 156. His body fat percentage was:
- Body fat percentage after 30 days of alternate-day fasting – 24.2%
He says he lost 4 pounds of pure fat, with the majority of those losses coming from his waist and core.
See the video for yourself below.
In Brendan’s opinion, trying to stay consistent with a fasting regime was easier than following a restrictive diet counting calories all the time and still with great results for fat loss.
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Intermittent fasting (IF) is a pattern of eating where individuals alternate between periods of eating and periods of fasting. There are several different methods of intermittent fasting, but the most common ones involve fasting for a set number of hours per day, or fasting for a full day or more on a regular basis.
Some of the benefits of intermittent fasting include:
- Weight loss: Intermittent fasting can help individuals lose weight by reducing the number of calories they consume. By limiting the hours during which you can eat, you naturally consume fewer calories.
- Improved insulin sensitivity: IF can help improve insulin sensitivity, which is important for maintaining healthy blood sugar levels.
- Reduced inflammation: Studies suggest that IF may help reduce inflammation in the body, which is linked to a number of chronic health conditions.
- Improved heart health: Some studies have found that IF may help reduce the risk of heart disease by lowering blood pressure, improving cholesterol levels, and reducing oxidative stress.
- Increased longevity: Some animal studies suggest that intermittent fasting may help increase lifespan, although more research is needed in humans to confirm this.

It’s important to note that intermittent fasting is not suitable for everyone, and it may have some potential risks and side effects. It’s always a good idea to speak with a healthcare professional before starting any new diet or eating pattern.
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There are several popular methods of intermittent fasting, including:
- 16/8 method: This involves restricting eating to an 8-hour window during the day and fasting for the remaining 16 hours.
- 5:2 diet: This involves eating normally for 5 days of the week and consuming only 500-600 calories on 2 non-consecutive days.
- Eat-Stop-Eat: This involves fasting for a full 24 hours once or twice a week.
- Warrior Diet: This involves eating one large meal for 4 hours and fasting during 20 hours.
- Spontaneous meal skipping: This involves skipping meals occasionally when it’s convenient or when you’re not particularly hungry.
It’s important to find an intermittent fasting method that works for you and your lifestyle. It’s also important to make sure you’re still getting all the necessary nutrients and calories your body needs during the times when you are eating. If you’re unsure about which method to try, it’s always a good idea to speak with a healthcare professional.
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What is alternate-day fasting?
Alternate-day fasting is a type of intermittent fasting where you alternate between days of normal eating and days of fasting. Typically, you eat for 12 hours on one day and then fast for the following 36 hours, repeating this cycle.
What inspired Brendan Jones to try alternate-day fasting?
Brendan Jones decided to try alternate-day fasting after researching its benefits. He found that it often resulted in greater fat loss compared to traditional calorie-restricted diets.
Is intermittent fasting suitable for everyone?
Intermittent fasting is not suitable for everyone. It may have potential risks and side effects, especially for individuals with certain medical conditions. It is recommended to consult a healthcare professional before starting any new diet or eating pattern.
How does alternate-day fasting compare to traditional calorie-restricted diets?
Research suggests that alternate-day fasting can result in greater fat loss compared to traditional calorie-restricted diets. Many find it easier to maintain due to not having to count calories every day.
What should you consider before starting alternate-day fasting?
Before starting alternate-day fasting, consider your overall health, lifestyle, and whether you can sustain the fasting periods. Consulting with a healthcare professional is crucial to ensure it is a safe and suitable method for you.
What happens to your body after 30 days of alternate-day fasting?
After 30 days of alternate-day fasting, Brendan lost 14 pounds, reducing his body weight from 170 pounds to 156 pounds. His body fat percentage decreased from 28% to 24.2%. He noted significant fat loss, particularly from his waist and core.
What are some benefits of intermittent fasting?
Intermittent fasting can lead to weight loss, improved insulin sensitivity, reduced inflammation, better heart health, and potentially increased longevity. However, these benefits can vary among individuals.
Can you maintain your exercise routine during the fasting period?
Yes, you can continue your strength training and running program while fasting. You may intensify your workouts on eating days to compensate for potentially lower energy levels on fasting days.
image sources
- Water and bowl: Cottonbro Studio on Pexels
- Doctor and body fat: Lucas Guimarães Bueno on Pexels