My interest in TRE (time restricted eating) began in 2016 after reading a scientific review article from 2014 on intermittent fasting vs calorie restriction for type 2 diabetes prevention. As a holistic nutritionist who lives by the philosophy of Food As Medicine, I am always intrigued to learn more about science supported techniques and nutritional strategies that support disease prevention and longevity.
This review article sparked my interest to delve deeper into the topic of intermittent fasting and time restricted eating (TRE) as practical dietary and lifestyle interventions for conditions such as obesity, heart health and other metabolic ailments that I could potentially implement into my nutrition practice.
I have always used myself as a test subject or guinea pig before utilizing any new dietary or health promoting protocol or nutraceutical that I deem reputable for my practice. In this case, I was very excited to try out the 16/8 version of intermittent fasting, whereby I would begin to narrow my eating window a few days per week to 8 hours and fast (including sleep hours) for 16 hours. After about 3-4 weeks of gradually shrinking my eating window by eating breakfast later and later, I was no longer hungry for breakfast, began to notice my notorious hangry symptoms weren’t occuring, my energy levels were more stable and I lost between 4-5 pounds.
As a result of my personal experience and my ongoing deep-dive into the research on intermittent fasting and TRE as a practical strategy to aid the public in staving off and even recover from various metabolic diseases, such as heart disease, type 1 & 2 diabetes, obesity, liver and kidney disease, my interest and implementation of these fasting protocols has continued to grow over the past 6 years.
So now let’s delve into how TRE can promote improved metabolic health and support sustainable fat loss.
What Is Time Restricted Eating (TRE)
Time Restricted Eating (TRE) or Time Restricted Feeding is a dietary protocol that limits the consumption of calories and sustenance to a limited time period; ideally under 12 hours of a 24 hour period. The concept of reducing the daily feeding window came out of longevity research that began in the 1930’s and revved up in the 1960’s and 1970’s which revealed that daily calorie restriction stimulated a number of metabolic pathways in the body that promote longevity. The early researchers of this work realized however that asking the general population to restrict their daily caloric intake by 30% for the rest of their lives was going to be a very hard sell. And this is where the concept of Intermittent Fasting came to be. Time restricted eating is a form of Intermittent Fasting (IF).
The most common TRE approach involves eating all of your daily calories within an 8- to 10-hour window, and then fasting for the remaining 14 to 16 hours of the day.
This style of eating closely mimics how our primal ancestors ate, with periods of feasting after a hunt and times of famine, when food was scarce. This natural feast to famine style of eating forced our ancestors to be metabolically flexible, allowing them to switch between our 2 energy resources; glucose and fat or ketones, the by-products of fat metabolism. One key health benefit and one of my main goals of practicing TRE was to become metabolically flexible. To be clear, metabolic flexibility refers to the body's ability to switch between different fuel sources, such as glucose and fat, depending on the body's needs and the availability of nutrients. When you are metabolically flexible, your body can efficiently switch between these fuel sources to maintain stable blood sugar levels and energy levels throughout the day.
And It was this metabolic flexibility that annihilated my previously incessant hangry symptoms.
How Can TRE Foster Metabolic Health?
Let me start by defining what metabolic health means. Metabolic health refers to a state of health that encompasses optimal metabolic functioning. This includes the body's ability to regulate blood sugar levels, maintain healthy blood lipid levels, and maintain a healthy weight and body composition.
Research has identified 5 primary biomarkers of metabolic health, which include:
Normal blood sugar (or glucose) levels
Healthy levels of blood lipids, including cholesterol (HDL & LDL) and triglycerides
Healthy blood pressure
Waist circumference (recommended to be less than 40 inches for men and less than 34.6 inches for women)
Optimal liver function
When we are metabolically healthy, our body is able to efficiently use and store energy from the food we eat, and it lowers our risk of developing metabolic disorders such as type 2 diabetes, cardiovascular disease, strokes and non-alcoholic fatty liver disease. With metabolic flexibility, we can reap quality of life benefits as well such as improved energy levels, consistent stable moods, sharper memory, improved sleep, less hunger and better weight control.
There are several ways that Time-restricted eating (TRE) can promote metabolic health.
By limiting the eating window to a shorter period of time each day, TRE can improve insulin sensitivity, promote weight loss in the form of fat loss, and reduce inflammation, all of which are important for metabolic health.
TRE can promote metabolic health through:
Improved insulin sensitivity: When you consume food, your body releases insulin to help transport glucose into cells for energy. Over time, excessive calorie consumption can lead to insulin resistance, which can increase the risk of developing type 2 diabetes and obesity. TRE can improve insulin sensitivity by allowing the body to take a break from insulin secretion and glucose uptake during the fasting period.
Increased fat burning: If the fasting period is long enough, the body has the opportunity to switch to burning stored fat for energy in the form of ketones, which are the by-products of fat metabolism. Enabling the body to shift into burning fat for fuel is an excellent way to promote weight loss and reduce body fat. This can help to improve metabolic health by reducing the risk of developing obesity, which is a risk factor for many chronic diseases.
Reduced inflammation: Chronic inflammation is a contributing factor to many metabolic disorders, including type 2 diabetes and cardiovascular disease. TRE has been shown to reduce inflammation by promoting autophagy, a process where damaged or dysfunctional cells are broken down and recycled.
Improved gut health: TRE has also been shown to improve the diversity and health of the gut microbiome, which can have a positive impact on metabolic health.
How exciting is it to know that we have the opportunity to implement a dietary protocol, centering around when we eat, that can have a dramatic positive impact on our long term health and well being?
Can TRE Aid in Fat Loss?
As mentioned above, it absolutely can. Time-restricted eating (TRE) can promote fat loss in several ways. By reducing your eating window to a shorter period of time each day, TRE can increase your body's ability to burn stored fat for energy.
Here are some ways in which TRE can promote fat loss:
Increased fat burning: During the fasting period, once glycogen (glucose storage in our muscles and liver) is fully utilized, the body switches to burning stored fat for energy. By limiting the eating window to a shorter period of time, TRE enables your body to become metabolically flexible like our primal ancestors naturally were; being able to burn both glucose and ketones for fuel. This metabolic flexibility promotes fat burning.
Reduced calorie consumption: By limiting your eating window, TRE can reduce the total amount of calories consumed each day. It is very important to be mindful of eating sufficient calories and optimal nutrition when practicing TRE. However, TRE can help to create a calorie deficit, by helping to promote higher energy levels, stable blood sugar, reduced cravings and snacking, which reduces overeating.
Improved insulin sensitivity: TRE can improve insulin sensitivity, which is important for fat loss. Insulin is the primary hormone that helps to regulate blood sugar levels and transport glucose into cells for energy. When insulin sensitivity is reduced, the body may store excess glucose as fat. By improving insulin sensitivity through TRE, your body is more efficient at using glucose for energy and less likely to store glucose as fat.
Early TRE benefits: Some recent research conducted over the past few years suggests that a weight loss strategy leveraging a TRE approach that focuses on eating early in the day, could be an effective strategy for overall weight loss as well as improved fat loss and cardiometabolic health. One study conducted from 2018-2020 compared Early TRE (eTRE), eating within an 8 hour window between 7- 3 pm to a self selected time window within 12 hours. Those results revealed a 50% increase in weight loss in the eTRE group.
Is TRE an Option for Everyone?
Here are some factors to consider when deciding if TRE is safe for you:
History of disordered eating: TRE may not be suitable for those with a history of disordered eating, such as anorexia nervosa, bulimia nervosa, or binge eating disorder. TRE may also trigger disordered eating behaviors in some individuals, so it's important to approach TRE with caution and under the guidance of a healthcare provider, such as a registered and certified nutritionist or registered dietitian.
Medical conditions: Some medical conditions may make TRE unsafe or unsuitable. Although TRE has been shown to assist in preventing and treating certain metabolic conditions like diabetes, if you already have been diagnosed with conditions such as diabetes, kidney disease, liver disease, or a gastrointestinal condition, it's very important to talk to your healthcare provider first to determine if TRE is safe for you.
Pregnancy and breastfeeding: TRE is not recommended for those who are pregnant or breastfeeding. Pregnant and breastfeeding individuals have increased nutritional needs and should not restrict their calorie intake without the guidance of a healthcare provider.
Medications: Some medications need to be taken with food, so make sure to speak with your healthcare provider to determine if TRE is safe while taking any medications. They will be able to adjust your medication schedule appropriately if needed.
Overall, TRE is safe and beneficial for most individuals, but it's important to talk to a healthcare provider before starting TRE to determine if it's safe and appropriate for you. If you decide to try TRE, I highly recommend starting the process gradually, listening to your body and adjusting your eating pattern as needed to ensure that you're meeting your nutritional needs and maintaining your overall health.
If you would like to embark on a TRE dietary regimen with professional guidance and support, reach out and allow me to assist you in the process. The benefits are so worth it: Lisa@livingproofnyc.com