The term “intermittent fasting” has become increasingly popular among health and fitness experts in recent years. Although not a new concept, more and more people are turning to intermittent fasting as an effective weight loss strategy, but also for a host of other long term health benefits –– but what is intermittent fasting, what are the different types of intermittent fasting and how can it help you achieve your goals? Read on for our guide to intermittent fasting for beginners.
What is Intermittent Fasting?
The term intermittent fasting refers to an eating pattern where one periodically eats little to no food for a specific amount of time. Depending on the schedule, that period of time may last from 12 hours (like a normal overnight fast) to several days.
Often, intermittent fasting is grouped in the same category as dieting and diet plans, but it’s different in that it focuses on when you eat, rather than on what you eat. Research has shown that intermittent fasting is a healthy, safe and effective pattern of eating, and that it does help many people lose weight or maintain a healthy body weight. Unlike diets that restrict calorie intake for extended periods of time, intermittent fasting can accelerate fat loss while also promoting muscle maintenance, and people tend to stick with it longer.
A growing body of research shows that intermittent fasting does a lot more than help burn fat. After about 12 hours of fasting glucose reserves have been used up and ketones become the primary source of fuel. This metabolic switch affects the body and brain in ways that are very likely to extend a healthy life span. For instance, it can reduce markers for inflammation and insulin resistance, promote cellular repair, and support resilience and growth of brain cells. All of these have implications for physical and cognitive performance, recovery and protection against chronic disease.
Although studies indicate intermittent fasting is safe and can be part of a healthy lifestyle, it may not be for everyone. It is still important to consult your primary care provider before starting any diet or specialized eating plan.
Different Types of Intermittent Fasting
There are several types of intermittent fasting, each centered around a different eating and fasting schedule. Among these, there are five common intermittent fasting methods that have been the focus of research. These include daily time-restricted feeding, alternate-day fasting, periodic fasting, the 5:2 hypocaloric fast, and the fasting mimicking diet.
The good news is that all of these protocols can help pump powerful ketones to your brain and body and have shown good results in promoting weight and fat loss, and supporting improvements in health and disease resistance. So, you can feel confident choosing an approach that suits your daily, weekly, or ongoing schedule, and experimenting until you find the type of intermittent fasting that's easiest to maintain over the long run.
Daily Time-Restricted Feeding
This method involves setting a daily time window for fasting and eating. The two most common are fasting for sixteen hours and eating for eight (16/8) or fasting for eighteen hours and eating for six (18/6). This method can fit well into most schedules, and because it’s the same pattern every day, it can easily become a routine that requires little to no extra planning or thought. For example, if you want to fast for 16 hours, it can be as simple as skipping breakfast. If you finish eating by 8pm and don’t eat lunch until noon, that’s already a 16 hour fast! This is arguably the best method for long term sustainability.
Alternate Day Fasting
Under this extensively researched method, fasting occurs for a full 24 hours every other day. On non-fasting days food is unrestricted. Nevertheless, research has shown that those who adopt Alternate Day Fasting can experience significant reductions in body weight and fat mass, especially after periods greater than 12 weeks.
This method, also known as Eat-Stop-Eat is similar to alternate day fasting in that it involves completely refraining from food for 24 hours. However, it’s only once or twice per week rather than every other day. This method provides an excellent “reset” for the digestive system.
This variation is a form of Modified Fasting where people eat normally for five days and then undergo calorie restriction for two non-consecutive days of the week. In general, calorie intake is reduced to between 500 and 600 calories per day on the “fasting” days. Some people find this easier than strict alternate day fasting or periodic fasting because there is never a window of time where you can’t eat food.
Fasting Mimicking Diet
A longer fast, the Fasting Mimicking diet s a type of intermittent fasting that spans the course of 5 days and requires users to eat a specific amount of calories –– from specific food sources –– based on their relevant heights and weights. Similar to the intermittent fasting protocols, this diet promotes the switch from glucose to ketones for fuel and has been shown to have similar weight loss and health and aging-related benefits.
Intermittent Fasting and Weight Loss
Intermittent fasting is an effective way to lose weight and burn fat. Additionally, one of the greatest highlights of intermittent fasting as a weight loss method is that it removes the need to count calories or consciously restrict your caloric intake. This makes intermittent fasting a great option for maintaining a healthy relationship with food while losing weight
Studies have also shown that human growth hormone (HGH) levels increase as much as five times when you integrate fasting of some type into your routine. Research has since linked increased levels of human growth hormone to greater body weight loss, muscle gain, and other health benefits. Unlike many diets that can make you feel sluggish and tired, intermittent fasting is designed to increase hormone levels to help you access stored fat reserves more easily –– which is crucial for anyone looking to enter and enjoy the benefits of ketosis.
The practice of intermittent fasting for weight loss eventually causes a metabolic switch. At the beginning of a fast, your body runs on stored glycogen. After fasting for about 12-16 hours, glycogen stores are depleted. Then, your body starts to produce ketones to fuel your brain and body by burning stored fat.
Of course, intermittent fasting can also lead to a wide range of weight loss benefits, but it’s important to always align your specific intermittent fasting plan or eating method with your goals. For example, while an alternate day fast may ultimately lead to greater fat loss, a time restricted fast may allow you to more consistently preserve lean muscle mass. As a result, if your ultimate goal is to expedite fat loss, you’ll be better served by an Alternate Day Fast, but if your goal is to bulk up or build muscle definition, you might want to explore a Time Restricted Fast.
Benefits of Intermittent Fasting
A growing body of evidence suggests that not only does intermittent fasting work, but it also has many benefits. These include improved weight management, cognition, longevity, and overall health. Other benefits of intermittent fasting include:
- Heart health can be improved by intermittent fasting as the bodily changes triggered by regular fasting can lower blood pressure and resting heart rate.
- Diabetes and obesity are other medical problems that can be addressed through fasting. In studies (conducted on animals), intermittent fasting helped prevent obesity, and in other human studies, participants achieved weight loss through intermittent fasting. Another study indicated fasting helps reduce insulin levels and insulin sensitivity. If you’re interested in how intermittent fasting can help you with any of these issues, make sure to discuss the eating pattern with your doctor or primary care provider today.
- Intermittent fasting can also help reduce inflammation and promote cellular repair and healing by triggering autophagy –– the process in which your body cleans out damaged cells for healthier ones.
- General cognitive and memory performance may also benefit from intermittent fasting. Some studies have shown fasting can improve working and verbal memory, as well as protect against some neurodegenerative diseases.
- Cognition, sensory-motor function and physical performance can be improved by an Intermittent Fasting regimen, especially if combined with vigorous exercise.
- Your body’s natural ‘Cell Growth Mode’ may be improved, as neurons may respond to the metabolic switch triggered by intermittent fasting by transitioning from a ‘cell preservation mode’ to a ‘cell growth mode’.
- Improved protection of neurons against stress, cell growth and neural plasticity can occur as a result of upregulated neurotrophic factor signaling induced by intermittent fasting.
- Finally, those lifestyles that undergo little to no intermittent fasting may actually result in suboptimal brain functionality and increase the risk of major neurodegenerative or psychiatric disorders.
The underlying mechanism powering these benefits is the metabolic switch from using glucose to burning fat and ketones for energy. Over time, the cellular responses that occur when this metabolic switch is triggered have actually adapted and evolved to optimize glucose regulation, increase stress resistance, and suppress inflammation.
As a result, when your body undergoes a fast, cells activate specific pathways made to defend against oxidative or metabolic stress. Then, during eating windows, your cells engage in tissue specific growth and plasticity processes. That said, those who opt for three meals a day, will never experience these health benefits of intermittent fasting.
Those who flip this metabolic switch periodically will be able to better harness the valuable ketone fuel that powers these changes and fuels cells during the fasting period. Additionally, they’ll also build out highly orchestrated systemic and cellular responses that can further bolster disease resistance, and ongoing mental and physical performance.
What Can You Eat While Intermittent Fasting?
Intermittent fasting is easy to incorporate into your daily routine because it restricts when you eat, not what you eat. However, what you eat is important too!
During A Fasting Period
While many believe fasting means putting nothing in the body, you can actually still enjoy certain things and preserve the benefits of fasting.
Many benefits of fasting come from ketosis, or elevated ketone levels. Here are some beverages you can consume while fasting that won’t kick you out of ketosis:
During an Eating Window
When you’re ready to break your fast, start by eating healthy foods and be sure not to over eat. Every time you break your fast, ketosis ends - especially if you eat carbohydrates. Following a low carb or keto diet in conjunction with intermittent fasting helps individuals stay in ketosis so they can continue to experience all the mental and health benefits like enhanced cognitive performance and increased energy.
Here are a few keto-friendly foods to eat when breaking your fast:
More important than counting your meals a day, it is essential to choose healthy, nutritious foods over high-calorie junk foods, fried foods, and sweets. If you decide to eat carbohydrates, make sure to select clean, complex, unrefined carbohydrates such as whole grains and leafy greens as these will set you up for better success, and help you achieve your goals.
Drinking Exogenous Ketones While Fasting
Many people turn to exogenous ketones while fasting. While exogenous ketone drinks and supplements may contain calories, the majority of these calories come from ketones - the same fuel your body is already running on while fasting. Ketones, like the D-beta-hydroxybutyric acid (D-BHB) and R-1,3-butanediol (R13BD) in Kenetik, cannot be converted into fat. This means that exogenous ketone products, like Kenetik, won’t compromise the metabolic switch from glucose to ketones, and in fact often appear to support it.
Almost more importantly, drinking Kenetik’s exogenous ketone while fasting can help users power through the initial discomfort that may come after starting a particular fasting regimen. In the past, studies have shown that it can take two to four weeks for the body to adjust to intermittent fasting. During this time, many users may experience hunger, irritability, and a reduced ability to concentrate during fasting periods. To combat this lapse in cognition, it’s important to turn to a BHB based exogenous ketone drink.
For example, in one study exploring the effects of following an intermittent fasting plan and metabolic switching on brain health, researchers found that , "By providing an alternative energy source and activating signaling pathways involved in neuroplasticity and cellular stress resistance, the ketone BHB plays a particularly important role in neuronal adaptations to fasting."
Beyond this, ketones also provide ample energy and help curb cravings, which will come in handy as you navigate your normal day-to-day tasks during your fasting period. When intermittent fasting as a beginner, exogenous ketones drinks, like Kenetik, may make it much easier to stick to –– or extend –– your fast.
Even if you’re not new to intermittent fasting, a BHB based product like Kenetik can make a world of difference in your usual fasting routine. And because exogenous ketone drinks send a rush of ketones to your brain and body, they may be just what you need when it comes time to hit the gym or pump out that last report while fasting.
So pick up a bottle of Kenetik today, or read on for more information about pairing Kenetik with intermittent fasting in our Guide to Intermittent Fasting.