Intermittent Fasting 19/5: The Scientifically-Backed Approach To Better Health 

Intermittent fasting has garnered significant attention from researchers and health enthusiasts. Its structured fasting and feeding windows have shown promise in promoting weight management, metabolic activity, and cellular repair. The 19/5 IF approach, in particular, is a balanced and achievable strategy for reaping the rewards of intermittent fasting.

What is Intermittent Fasting 19/5?

Like any other IF approach, the 19/5 method is a time-restricted strategy where you fast for 19 hours and eat in a five-hour window.

During the fasting window, zero-calorie food or beverages are allowed, whereas the eating window has no specific restrictions. However, you must avoid a late-night meal to prevent disruptions to your body’s circadian rhythm.

As the eating window in the 19/5 method is small, you must have one or two nutrient-dense meals. This will lead your body to burn stored fat for energy during the extended fasting period.

Related: Foods You Should Eat While Intermittent Fasting

Examining the Science Behind Intermittent Fasting 19/5

Before we understand the science behind the 19/5 method, let’s understand the mechanism of intermittent fasting. This time-based eating technique, or the fed-fast cycle, generally has four stages:

Fed State

The state begins soon after we consume food, and our body in this stage is busy actively digesting and absorbing nutrients from our recent meal. The elevated levels of glucose in the blood trigger insulin release, a hormone that helps transport glucose from the bloodstream into cells for energy production. Simultaneously, excess nutrients, such as glucose, amino acids, and fatty acids, are stored for future use. The fed state typically lasts about 3-5 hours after a meal.

Post Absorptive State (Early Fasting State)

After absorbing nutrients from the recent meal, the body enters the postabsorptive state, also known as the early fasting state. In this stage, the body relies on stored energy reserves to maintain proper functioning. The post-absorptive state typically lasts 5-12 hours after the last meal.

Fasting State

As the duration of fasting extends beyond the postabsorptive state, the body enters the fasting state. In this phase, the body’s glucose reserves are depleted, relying more on stored fats as the primary energy source. It generally lasts from 12 hours to several days.

Starvation or Long-Term Fast State

This occurs when the body has depleted its glycogen stores and significantly reduced fat stores. In this prolonged fasting state, the body continues to rely on ketones as its primary energy source. As the body tries to conserve energy, the metabolic rate decreases, and certain bodily functions slow down. [1]

That is how IF functions in general. Intermittent fasting 19/5, also known as fast-five fasting, shares similar principles and effects with other intermittent fasting methods, such as 16:8 and 5:2. Like others, the key objective of this intermittent fasting approach is to prompt the body to utilize stored fat as an energy source. This process may not occur during traditional three-meal-a-day eating patterns.

Without time-restricted eating, the body relies on carbohydrates from regular meals for energy, leaving the unused fat to accumulate within the body.

This accumulation of fat results in obesity, leading to health concerns like diabetes mellitus, cardiovascular disease, hypertension, and hyperlipidemia. [2]

19/5 vs. 16/8 Intermittent Fasting — Similarities & Differences

Given that both IF strategies follow a fast-fed cycle within 24 hours, it’s natural to ponder which is more effective.

The 16/8 method involves fasting for 16 hours and eating within an eight-hour window. You can choose the food you want to eat during your eating window. However, you must avoid junk food. Also, you can select your eating window according to your preferences.

Similarities

The 19/5 and 16/8 fasting methods have several similarities, including:

• They both trigger the same metabolic responses in the body as the fed-fast cycle is the same. During fasting, insulin levels decrease, prompting the body to tap into stored fat for energy. This fat-burning state can lead to weight loss and improved metabolic health.
• They both are great for controlling blood sugar, high insulin sensitivity, improving lipid profiles, reducing cardiovascular disease risks, and elevated adiponectin levels. [3]
• You can choose the foods and eating windows in both methods.

Differences

The eating window lasts for different durations in both methods. The 19/5 method involves a five-hour feeding window, whereas the 16/8 method comprises eating in eight-hour cycles.

As the eating window differs, eating frequency varies in these regimes. In the 19/5 method, one meal with a quick snack break is generally preferred. On the other hand, the 16/8 regime allows for two or more meals distributed throughout the eight-hour eating window.

The fat-burning ratio is also different in both approaches. As you fast for longer in the 19/5 method, fat loss is likely more significant than in the 16/8 method. However, the results can vary for each individual. If similar healthy IF meals are consumed in both regimes, 19/5 will likely deliver faster and better results.

Considering all these points, I have no qualms about stating that both these approaches deliver results. The decision between 19/5 and 16/8 intermittent fasting comes down to individual preferences, lifestyle, and health goals.

Eating Recommendations For 19/5 Intermittent Fasting

Before starting 19/5 intermittent fasting, you must make conscious choices regarding having balanced and nutritious meals. Eating unhealthy foods will lead to suboptimal results. So, you must select nutrient-dense foods that fuel your body for an extended period, even if you have a short eating window.

Here is what you need to remember while eating on the 19/5 method.

Consume Balanced Macronutrients

Try to include a balanced mix of macronutrients in your meals so that your body gets plenty of protein, healthy fats, and carbohydrates. These macronutrients are essential for proper body functioning. For instance, protein-rich foods can help with satiety and muscle maintenance, while healthy fats and complex carbohydrates provide sustained energy. [4]

Include Fruits and Vegetables

Opt for nutrient-dense foods rich in vitamins, minerals, and antioxidants. These nutrients are vital for various physiological processes, including energy production, immune function, cellular repair, and overall health maintenance. Adequate nutrient intake supports healthy growth, development, and cognitive function.

Eat plenty of fruits, vegetables, whole grains, nuts, seeds, and lean proteins to meet your daily micronutrient needs. As they are low-calorie foods, it’s a win-win situation for you as you get vital nutrients without consuming excess energy. [5]

Stay Hydrated

Water is your best friend during extended fasts. A glass of lime or plain water can help you feel satiated. Since water is a zero-calorie drink, you can consume it guilt-free during fasting. [6]

Avoid Sugary and Processed Foods

If you don’t want your fasting efforts to go in vain, avoid sugary and highly processed foods. These types of food lead to a sudden hike in blood sugar levels resulting in energy surges and high blood sugar levels.

Another problem with sugary and processed foods is that they are low in fiber and protein, leading to a quick spike in energy followed by a crash. This can result in increased hunger and cravings, making it challenging to adhere to the fasting period and practice self-control during the eating window.

Also, these types of foods are typically devoid of essential nutrients and contain empty calories. Given your restricted feeding periods, eating junk foods can lead to nutritional deficiencies.

Say No To Late Night Dinners

While you can pick an eating window during the 19/5 method, the wise move would be not to keep it late at night. Late-night dinners disturb the body’s circadian rhythm and hurt sleep quality.

If your body does not get enough time to process and digest food, issues like indigestion, acid reflux, and discomfort while sleeping tend to arise. It disrupts sleep patterns, leaving you feeling unrested and fatigued the next day.

Remember, the key to successful intermittent fasting is finding an eating pattern that aligns with your lifestyle, preferences, and health goals. By making conscious and nutritious choices during your five-hour eating window, you can optimize the benefits of the 19/5 intermittent fasting method.

Foods To Eat While 19/5 Intermittent Fasting

Being mindful of your food choices during the 19/5 intermittent fasting schedule is crucial. It’s important to choose nutrient-rich foods to prevent nutrient deficiencies. Also, your food should be satiating to avoid craving episodes. Here are the foods that should be a part of your 19/5 IF dieting regime:

Lean Proteins for Everything Good

As protein is the building block of the human body, your 19/5 dieting plan should have enough lean protein food sources. Some options are turkey, fish, lean-cut beef, and chicken breast.

While animal-based lean protein is mainly recommended to meet your daily protein intake, there are also some plant-based options. Vegans must include legumes like pinto beans, black peas, chickpeas, lentils, tofu, seitan or wheat gluten, and quinoa, as they are also rich in protein.

Not only do they keep your body healthy, but lean protein also keeps you full for longer, so you don’t have frequent hunger pangs.

Related: Protein intake calculator

Healthy Fats

Not every fat is bad. Healthy fats from nuts and seeds are good for your heart health. Monounsaturated and polyunsaturated fats are best known to lower LDL cholesterol levels and promote cardiovascular well-being.

Including fats in your 19/5 diet plan is vital for multiple reasons. For starters, fats support the effective absorption of fat-soluble vitamins like A, D, E, and K, along with certain phytonutrients. Olive oil is also a great source of healthy fat. Use it in salad dressing and let it do its wonders.

Foods to Avoid During 19/5 Fasting

You should stay away from the following foods:

• Refined carbohydrates like white bread, white rice, pasta, and cookies. These lead to insulin spikes and affect fasting benefits.
• Gums and mints as these might have sugar and can lead to insulin level imbalances.
• Ready-to-cook meals as they are often low in nutrients and high in preservatives. If you consume too much processed foods, you might fail to get adequate nutrients during your short eating window.

19/5 IF Method — Is it the Right Choice For Me?

Before you get excited to try the 19/5 method, you must understand that this is not everyone’s cup of tea. This is an advanced version of IF that requires more commitment and self-resilience. This is not the suitable IF method for you if:

You’re an intermittent fasting beginner

This regime is not your best bet if you’re an intermittent fasting newbie. Fasting for 19 hours straight is something your body won’t adapt to immediately. So, the ideal move is to go slow and then advance slightly.

You’re not in your best form and are dealing with some diseases

The 19/5 method is not for you if you deal with health conditions like asthma, heart disease, and high blood pressure. Fasting for 19 hours can be stressful on your body, and individuals suffering from any of these health conditions might have a tough fasting period.

Also, pregnant women, elderly individuals, and kids under 18 should avoid the 19/5 method due to their unique nutritional requirements and health sensitivities.

Is 19/5 IF the Right Choice For You?

The 19/5 intermittent fasting method is considered more advanced and may not be suitable for IF beginners, older individuals, or those with underlying health conditions. Since pregnant women have unique nutritional requirements and need proper meals to support their and their baby’s health, the 19/5 IF method is not recommended for them.

It is essential to make informed choices based on your health needs and consult your healthcare provider when considering the 19/5 IF method.

FAQs

Are the 19/5 and 16/8 methods the same?

No, they are not the same. Even though both IF regimes have almost the same benefits, they are not identical approaches. The 19/5 method involves fasting for 19 hours and eating in a five-hour window, whereas the 16/8 method comprises fasting for 16 hours and limiting the eating window to eight hours.

What to eat during 19/5 fasting?

Consume nutrient–dense and well–balanced food during your eating window. In your fasting window, you can consume water and calorie-free beverages like water.

Should I exercise while following the 19/5 IF method?

Light and moderate exercise are considered safe while fasting. Make sure you understand your body’s needs and adapt accordingly.

Wrapping Up

If you’re already on an intermittent fasting journey and seeking to take it to the next level, consider trying the 19/5 intermittent fasting method. The 19-hour fasting and five-hour eating windows pose several benefits and challenges. Consider your health and circumstances while embarking on this journey.

Whether you are trying to lose weight or improve your overall health, making informed decisions while adhering to the information presented in this article can help you navigate through 19/5 IF safely and effectively.

References

1. Stockman, M. C., Thomas, D. D., & Burke, J. (2018, April 26). Intermittent Fasting: Is the Wait Worth the Weight?
2. Obesity. (2023, January 1). PubMed.
3. Song, D. K., & Kim, Y. W. (2023, January 31). Beneficial effects of intermittent fasting: a narrative review.
4. Carreiro, A. L., Dhillon, J., Gordon, S., Higgins, K., Jacobs, A., McArthur, B. M., Redan, B. W., Rivera, R., Schmidt, L., & Mattes, R. D. (2016, July 17). The Macronutrients, Appetite, and Energy Intake. Annual Review of Nutrition; Annual Reviews.
5. Nicklas, T. A., Drewnowski, A., & O’Neil, C. E. (2014, August 28). The nutrient density approach to healthy eating: challenges and opportunities. Public Health Nutrition; Cambridge University Press.
6. Bracamontes-Castelo, G., Bacardí-Gascón, M., & Cruz, A. J. (2019, January 1). Effect of water consumption on weight loss: a systematic review. Nutricion Hospitalaria; Arán Ediciones.

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