Intermittent Fasting: A Health Strategy, Not a Shortcut to Virtue or Vitality
- Chase Crouse
- Jun 21, 2025
- 5 min read
Intermittent fasting (IF) has exploded in popularity over the last decade, often presented as a “biohack” or a shortcut to weight loss and longevity. On the surface, it can sound strikingly similar to the spiritual practice of fasting and abstinence that Catholics are called to observe, especially during Lent or on designated Fridays. But while both involve going without food for a time, their purposes, and their effects, are very different.
In this blog, we’ll explore what intermittent fasting actually is, how to do it effectively, and why, despite the hype, it’s not necessarily better for your health or fat loss than a more traditional calorie deficit. We’ll also touch on the spiritual practice of fasting to help Catholics understand how to separate physical discipline from religious devotion.
Fasting: Spiritual Discipline vs. Health Trend
Let’s start by making an important distinction. Religious fasting, such as that practiced by Catholics, is not about weight loss. It’s a spiritual discipline, meant to train the will, encourage detachment from worldly pleasures, and unite our small sufferings with Christ’s. The Catechism of the Catholic Church puts it beautifully:
“The seasons and days of penance in the course of the liturgical year (Lent, each Friday in memory of the death of the Lord) are intense moments of the Church's penitential practice. These times are particularly appropriate for spiritual exercises, penitential liturgies, voluntary self-denial such as fasting and almsgiving...” (CCC 1438).
So while Catholic fasting may have health benefits as a secondary effect, its primary aim is spiritual growth.
Intermittent fasting, on the other hand, is a secular dietary strategy. It focuses on when you eat rather than what you eat, and is often promoted as a way to lose fat, boost energy, and simplify eating. It can certainly be practiced by people of faith, but its purpose is fundamentally different, and it’s important not to conflate the two.
What is Intermittent Fasting (IF)?
Intermittent fasting refers to eating only during specific windows of time and fasting (not eating) during others. Some of the most common IF methods include:
16:8 Method: Fast for 16 hours, eat during an 8-hour window each day (e.g., from 12 PM to 8 PM).
5:2 Method: Eat normally five days a week, and consume only about 500–600 calories on two non-consecutive days.
Alternate-Day Fasting: Fast every other day, or eat very minimal calories on fasting days.
OMAD (One Meal a Day): Consume all daily calories in a single meal.
While these methods may vary, the underlying idea is to reduce the overall amount of food consumed by shrinking the eating window, which can help some people more easily manage their calorie intake.
How to Do Intermittent Fasting Well
If you decide to try IF, it’s important to remember that it’s not a license to binge during your eating window. Here's how to approach it in a balanced and sustainable way:
Choose a Realistic Window: The 16:8 method is often a good starting point. If you normally snack late into the night, try pushing breakfast back gradually and stopping dinner earlier.
Prioritize Nutrient-Dense Foods: Just because you’re eating less often doesn’t mean you should eat low-quality food. Meals should include lean proteins, healthy fats, fiber, fruits, and vegetables.
Stay Hydrated: Drink plenty of water throughout the day. Black coffee, tea, and other non-caloric beverages are typically fine during fasting periods.
Be Flexible: Life happens. If you’re celebrating a feast day, traveling, or just not feeling great, it’s okay to adjust your fasting window or skip it altogether.
Avoid the “Magic” Mindset: Fasting is not a miracle solution. Its effectiveness still depends on the quality and quantity of the food you consume.
Why Intermittent Fasting Isn't Necessarily Better Than a Calorie Deficit
Intermittent fasting can help people lose weight, but so can a standard calorie deficit where meals are spread throughout the day. In fact, research shows that total energy balance (calories in vs. calories out) is still the main driver of fat loss, regardless of meal timing.
A 2022 study published in The New England Journal of Medicine found that people who practiced time-restricted eating lost no more weight than those who ate the same number of calories without time restrictions. The takeaway? IF is a tool, not magic.
Additionally, IF may not be suitable for everyone. People who:
Struggle with disordered eating
Are pregnant or breastfeeding
Have blood sugar regulation issues
Have high physical demands or athletic performance goals
...may find intermittent fasting counterproductive or even harmful.
The Benefits—With a Grain of Salt
That said, IF does offer some practical advantages:
Simplicity: Fewer meals = fewer decisions.
Improved Hunger Awareness: Some find they learn the difference between true hunger and boredom.
Insulin Sensitivity: Some studies suggest improved blood sugar regulation, though results are mixed.
Reduced Late-Night Snacking: Ending eating earlier in the evening may improve digestion and sleep.
But these benefits often come from reduced calorie intake and improved dietary discipline, not from fasting itself.
A Catholic Perspective on Food and Discipline
For Catholics, it’s good to develop discipline over our appetites, but not to become obsessed with control. Food is a gift from God. It's meant to nourish us and be enjoyed in gratitude.
If you’re using intermittent fasting as a health strategy, approach it with humility. If it becomes a source of pride, excessive control, or vanity, it may be doing more spiritual harm than physical good.
St. Paul reminds us:
“So, whether you eat or drink, or whatever you do, do everything for the glory of God.” (1 Corinthians 10:31)
You don’t have to fast to be holy or healthy. But both goals benefit from intentionality, balance, and a desire to glorify God with your body (cf. 1 Corinthians 6:19-20).
Final Thoughts
Intermittent fasting can be an effective, flexible strategy for managing food intake and supporting fat loss, but it’s not a silver bullet. It’s also not superior to a consistent, sustainable approach to healthy eating built on whole foods and mindful habits.
As a Catholic, you’re already called to practice fasting at appropriate times for spiritual growth. If you decide to fast intermittently for physical health, do so with discernment, understanding, and a spirit of moderation.
In both cases, the goal isn’t just better health. It’s greater mastery of self, for the sake of love and service.
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