Intermittent Fasting

8-hour eating window for 31 days

Study RESULTS

The study involved participants engaging in a 8-hour eating window for 31 days (commonly knows as Intermittent Fasting). Data was self-reported, using a Likert scale from 1 (strongly disagree) to 7 (strongly agree) across various health and psychological metrics. The analysis includes both quantitative data and qualitative based on responses from 219 participants.

Physical Health Impact
Strongly Disagree
Disagree
Somewhat Disagree
Neutral
Somewhat Agree
Agree
Strongly Agree
Physical Health Improvement
I feel my overall physical health has improved as a result of doing this challenge.
avg: 5.5
Energy Levels
I feel I have more energy throughout the day.
avg: 5.5
Fitness Improvement
My overall physical fitness level has improved as a result of doing this challenge.
avg: 5.2
Endurance Improvement
My physical endurance has improved because of this challenge.
avg: 5.1
Flexibility Improvement
My flexibility or mobility has increased.
avg: 4.7
Pain Reduction
I have experienced less physical pain or discomfort.
avg: 5.0
Strength Improvement
I feel physically stronger as a result of doing this challenge.
avg: 5.0
Sleep Improvement
My sleep quality has improved.
avg: 5.0
Adverse events
I had adverse events that I directly link to doing this activity (sickness, injury etc).
avg: 2.5
Mental Health Impact
Strongly Disagree
Disagree
Somewhat Disagree
Neutral
Somewhat Agree
Agree
Strongly Agree
Mood Improvement
I have experienced a more positive mood during this challenge.
avg: 5.4
Calm and Relaxation
I feel a greater sense of calm and relaxation during this challenge.
avg: 5.2
Concentration Improvement
My concentration or focus has improved.
avg: 5.1
Stress Reduction
I have noticed a reduction in feelings of stress or anxiety during this challenge
avg: 5.0
Other
Strongly Disagree
Disagree
Somewhat Disagree
Neutral
Somewhat Agree
Agree
Strongly Agree
Difficulty as Daily Routine
It would be hard to make this challenge a part of my daily routine
avg: 2.5
Challenge Enjoyment
The challenge was fun for me to do.
avg: 5.9
Resource Consumption
The challenge was time & resource consuming.
avg: 2.3
Plan to Continue
I plan to continue this practice beyond the challenge.
avg: 6.1

Qualitative Analysis - Key Themes and Insights

The qualitative analysis draws on open-ended responses from all 203 participants, regardless of adherence, to the questions about the most beneficial aspects of the challenge and extraordinary experiences or discoveries. Thematic analysis was conducted to identify recurring themes, with coding performed to quantify prevalence and highlight compelling insights.

1. Beneficial Aspects

The following themes emerged as the most common and impactful benefits, ranked by frequency:

- Weight Loss and Body Composition (n = 62, 31%): Participants frequently cited weight loss (e.g., "Lost 5kg," "Lost 7 kg") and reduced bloating (e.g., "Fitting better in my clothes") as primary benefits. Example: "I lost weight and maintained it throughout the challenge."

- Discipline and Self-Control (n = 58, 29%): Many highlighted improved discipline and control over eating habits, particularly in avoiding late-night snacking or emotional eating. Example: "Improved self-discipline and better control over my eating habits. Being consistent is the key."

- Improved Eating Habits (n = 45, 22%): Participants noted mindful eating, reduced snacking, and healthier food choices (e.g., "I stopped snacking late, and eat my dinner early"). Example: "I now have a better relationship with food. I enjoy making and eating healthy foods."

- Increased Energy and Mental Clarity (n = 38, 19%): Enhanced energy, focus, and mental clarity were frequently reported, often linked to reduced inflammation or better digestion. Example: "Much clearer mentality and energy."

- Health Benefits (n = 32, 16%): Specific health improvements included better digestion, reduced inflammation, and lower blood sugar or blood pressure. Example: "Reduced blood sugar levels and blood pressure."

- Accountability and Community (n = 25, 12%): The challenge's structure and community aspect fostered accountability, motivating adherence. Example: "Accountability of something I want to do, but often talk myself out of."

- Improved Sleep and Relaxation (n = 20, 10%): Better sleep quality and a sense of calm were noted, often tied to reduced evening eating. Example: "Better sleep."

2. Extraordinary Experiences and Discoveries

Participants shared unique insights and transformative experiences, with the following themes most prevalent:

- Unexpected Resilience and Willpower (n = 48, 24%): Many were surprised by their ability to fast without excessive hunger or discomfort (e.g., "I have more willpower than I thought"). Example: "I surprised myself by sticking to the challenge for the whole month and didn't break it once."

- Health Discoveries (n = 42, 21%): Participants reported unexpected health improvements, such as reduced IBS symptoms, lower back pain relief, or decreased sugar cravings. Example: "Prior to the challenge, I had experienced a strong pain in my lower back for more than 3 months. Surprisingly, it vanished towards week 3."

- Changed Relationship with Food (n = 35, 17%): Many discovered they could eat less without obsession or reliance on snacking, shifting their perspective on food. Example: "This challenge has completely changed my relationship with food. I no longer obsess over food and I have learned to trust my body instead."

- Mental and Emotional Breakthroughs (n = 30, 15%): Participants noted increased confidence, reduced emotional eating, and spiritual or emotional clarity. Example: "Better intuition, spiritual connection. Received messages of Faith, discovered leadership qualities without trying."

- Physical Transformations (n = 25, 12%): Visible changes, such as reduced visceral fat or increased muscle definition, were celebrated. Example: "Belly/abdomen fat has gone down remarkably. Most likely visceral fat."

- Community and Social Connections (n = 15, 7%): Sharing the challenge with others, including family or online communities, enhanced motivation and connection. Example: "I didn't realise how many people in my family were familiar with intermittent fasting, as well as work colleagues."

- Challenges and Negative Experiences (n = 12, 6%): A minority reported difficulties, such as hunger, stress, or adverse health effects (e.g., "Rapid decline in mental health which made me stop after just 3 days"). Example: "I found myself more stressed with increased cortisol levels and inflammation."

3. Notable Qualitative Patterns

- Beginners vs. Experienced: Beginners (n = 110) often emphasized discipline and weight loss as novel benefits, while those with prior experience (n = 93) highlighted refined eating habits and sustained health improvements.

- Age Trends: Younger participants (18–34, n = 28) frequently noted mental health benefits and willpower discoveries, while older participants (55+, n = 52) emphasized physical health and sleep improvements.

- Gender: Females (n = 176) were more likely to report emotional and relational benefits (e.g., community, reduced emotional eating), while males (n = 26) focused on physical outcomes (e.g., weight loss, strength).

- Adherence Impact: Even participants with lower adherence (<90%, n = 52) reported benefits like improved eating habits, suggesting partial engagement still yielded positive outcomes.

Summary and Conclusions

Overview: This study demonstrates that an 8-hour intermittent fasting challenge over 31 days is associated with significant physical, psychological, and lifestyle benefits, particularly among highly adherent participants (90–100%). The qualitative responses reveal a broad spectrum of benefits, with weight loss, discipline, and improved eating habits as the most common outcomes.

Key Insights:

- Weight Management and Body Composition: Weight loss emerged as the most frequently cited benefit (31% of participants), with many reporting sustained weight loss and improved body composition, including reduced bloating and visceral fat reduction.

- Behavioral Transformation: The challenge fostered significant improvements in self-discipline (29%) and eating habits (22%), with participants developing better control over emotional eating and late-night snacking behaviors.

- Physical and Mental Well-being: Participants experienced enhanced energy and mental clarity (19%), along with specific health improvements including better digestion, reduced inflammation, and improved blood markers.

- Personal Empowerment: Many participants discovered unexpected resilience and willpower (24% of extraordinary experiences), leading to increased confidence and a transformed relationship with food.

Most Common and Interesting Findings:

- Most Common Benefits:

  • Weight Loss: The primary benefit reported by nearly one-third of participants, often accompanied by sustained maintenance throughout the challenge.

  • Improved Discipline: Participants valued the development of self-control and better eating habits, particularly around evening snacking and emotional eating patterns.

  • Enhanced Energy and Clarity: Mental and physical vitality improvements were frequently linked to reduced inflammation and better digestion.

- Most Interesting Extraordinary Experiences:

  • Unexpected Health Discoveries: Participants reported surprising health improvements, such as relief from chronic lower back pain after 3 months of suffering, reduced IBS symptoms, and decreased sugar cravings.

  • Transformed Food Relationship: Many discovered they could maintain healthy eating patterns without food obsession, learning to trust their body's natural hunger signals.

  • Spiritual and Emotional Breakthroughs: Some participants experienced profound personal insights, including enhanced intuition, spiritual connections, and discovery of leadership qualities.

Demographic and Experience Patterns:

- Experience Level Impact: Beginners focused on fundamental benefits like discipline and weight loss, while experienced practitioners emphasized refined eating habits and sustained health improvements.

- Age-Related Benefits: Younger participants prioritized mental health and willpower discoveries, while older adults emphasized physical health and sleep quality improvements.

- Gender Differences: Female participants were more likely to report emotional and community-related benefits, while male participants focused primarily on physical outcomes.

Conclusion:

The 8-hour intermittent fasting challenge proved highly effective in promoting comprehensive health and lifestyle improvements. Participants valued IF for fostering mindfulness, reducing unhealthy snacking, and enhancing energy and mental clarity. Extraordinary experiences underscored personal empowerment, with many discovering unexpected resilience, significant health improvements, and a fundamentally transformed relationship with food. While a small minority faced challenges such as stress or hunger, the overwhelmingly positive narratives highlight IF's potential as a sustainable, impactful practice. The sense of community and accountability further amplified engagement and success, with implications for public health promotion and personalized lifestyle interventions. Future research should explore long-term outcomes and mechanisms underlying IF's diverse benefits.

< Back to The Intermittent Fasting Challenge

Join our newsletter to get informed about the launch
upcoming challenges

By clicking “Subscribe”, you agree to receiving emails and to processing of your personal data in accordance with the Privacy policy

Frequently asked questions

How do I join a Challenge?
There is a "Join Challenge" button for any active challenge. There will be 12 Challenges per year. You are free to join any time however joining on the first day of a given month is how the game is meant to be played to experience a full month of a given challenge.
What are the instructions for a Challenge?
All necessary instructions are always found on the page of a particular challenge. If you haven't received the email 1 day prior to the Challenge don't worry! The email only contains a part of the message which is included on the Challenge page anyway. But the instructions are really extremely simple. For the "10.000 Steps Challenge" it could be "Just walk at least 10000 steps per day". For the "Meditation Challenge" it would be "Just sit and meditate for 15 minutes a day, anywhere, at any time, with any meditation method you can find online".
Where are the Challenges happening?
All Challenges can be done from your location. Each Challenge is done in such a way that there is no particular location to attend to.
At what time during the day do I have to do a Challenge?
Challenges can be done at any time during the day, whether it's morning, evening, or mid day. Though it is much easier to stick to a routine in the morning as mornings can be typically controlled whereas the evening tends to be more chaotic and have unscheduled tasks that need attending.
Is this FREE?
Yes, all challenges are and always will be free to join and participate in.
Why trust us?
We’re not selling anything. We’re learning alongside you
How do the monthly $3000 prizes work exactly?
There will be 3 (three) $1000 prizes per chosen Challenge (not all Challenges will have prizes). To be eligible for the prize one has to share their daily journey with a hashtag chosen for each Challenge. Then, After the Challenge has ended send in the links to specific videos to [email protected] where the posts can be verified. At the end of a Challenge the 3 winners will be chosen by TheChallenge.org team based on the most well done daily documentation of a given Challenge. Numbers of followers, likes, comments on social media etc WILL NOT matter. Read all the requirements here and in the contest terms in each of the Challenge pages near the sign-up area.
I don't have an Instagram or YouTube account, can I still participate?
Absolutely! You don't need to do anything to participate since the challenges can be done from anywhere. To sign up and receive updates about the challenge or to be able to contribute to a science questionnaire at the end you just need to have an email and join a Challenge on the website. Instagram or Youtube accounts are only a requirement for people who want to have a shot at the Prizes. That however requires daily posting on those channels for a whole month so is very rarely done. Approximately 99.5% of all Challenge Participants do it for the Challenge itself and do not post daily on their social media channels. We are just happy if you do the Challenge!
Is this a non-profit organization?
TheChallenge.Org is a for-knowledge organisation. The organisation is not a typical non-profit. It will have an optional donation model for people wanting to support it and help cover the cost of operations.
Who are the people behind this project?
Karol Banaszkiewicz, our founder, is a seasoned technologist and lifelong health-hacker who noticed a glaring gap in how we track the real effects of daily routines. Driven by a passion for data-backed self-improvement, he committed his own time and resources to launching TheChallenge.Org—to rigorously measure how habits shape our physical and mental well-being.
FAQs
s