The Art and Science of Time-Restricted Eating: Part 1 (Intermittent Fasting)
The Food Dilemma
Ever open a fully stocked fridge, glance for a few seconds and then grab your car keys and head to Taco Bell? Me too. Today food is more accessible than ever before. Technological advancements in food processing have significantly lowered the price of what we eat but has also made our food less nutrient dense. That’s why cultivating good eating habits is critical to optimizing the nutritional aspect of your life and TRE is the perfect starting point.
Time-Restricted Eating (TRE) is when you eat all your calories for the day in a certain window of time (e.g. 8 hours, 10 hours, or 12 hours ). Note: time-restricted eating is the same thing as intermittent fasting (IF).
So…what does TRE even do and why is everyone raving about it?
Here’s the answer. A study lead by Dr. Satchin Panda, a professor of biology at the Salk Institute, revolutionized the health world when his team ran a 12-week experiment on adults testing the effects of time-restricted eating on body weight. One group of adults ate anytime it wanted throughout the day and the other group consumed all its calories in an 8 hour window. The results were shocking in the TRE group:
- Decrease in Bodyweight by ~3%
- Decrease in Daily Calorie Intake by ~300 calories
- Lower Blood Pressure
This means that by not even changing what you eat or how much you eat but by simply eating all your calories in a fixed window of time you can lose bodyweight.
But wait…it gets better!
eTRE or Early Time-Restricted Eating is a form of TRE that involves eating earlier in the day and in an even shorter window of time (6 hours) in order to better align your eating with circadian rhythms in metabolism. A study in Cell Metabolism tested the effects of eTRE by having one group of men restrict feeding to a 12 hour window and the other group restrict feeding to a 6 hour window. The results were stunning in the eTRE group. Here they are:
- Improved Insulin sensitivity
- Improved Beta Cell Responsiveness
- Improved Blood Pressure
- Less Oxidative Stress (cellular damage)
- Improved Appetite (more satiety, less cravings)
The benefits don’t stop there. The proliferation of evidenced based TRE research shows us that this simple nutritional habit can single handedly improve many facets of your life. Here’s a brief look at the many benefits of TRE:
- Normalizes Glucose (Blood Sugar)
- Normalizes Cholsterol
- Improves Cardiac Function (Reduced Arrhythmia)
- Reduces Inflammation
- Improves Sleep Quality
- Increases Endurance
- Improves Immune Function
- Improves Gut Microbiome Health
- Normalizes Bowel Movements
- Improves Motor Coordination
Time-Restricted Eating + Calorie Restriction for Weight Loss
Calorie restriction (CR) is when you eat less calories than your body uses on a daily basis. This is not to be mistaken with fasting. Fasting involves not eating for a certain period of time and is usually followed by consuming a normal amount of calories when the fast is over.
Most of the time people calorie restrict in an effort to lose weight. Logically this makes sense. Eat less, lose more. It’s true. (CR) is hands down the most effective method for weight-loss. It’s is also known to be a primary factor in increasing longevity (helping you live longer).
Be aware, long periods of calorie restriction can lead to a host of problems including the downregulation (slowing) of metabolism which translates to burning less calories per day and storing more energy as body fat. Adding calorie restriction to a TRE program is a great way to burn some serious fat. Just make sure to normalize caloric intake after reaching your desired weight. Pros and cons of calorie restriction:
- Weight Loss
- Increased Lifespan
- Downregulation of Metabolism (Burn less calories on a daily basis)
- Downregulation of Testosterone Production
- Downregulation of Libido (Less drive to get cheeks)
Time-Restricted Eating + Exercise for Muscle Maintenance and Fat Loss
An 8-week study on resistance trained athletes found that an 8-hour TRE program in combination with exercise can:
- Decrease Fat Mass
- Maintain Muscle Mass
- Increase Health Related Biomarkers
By adding some weekly high intensity training sessions to your TRE program you can shred even more fat and maintain lean muscle mass. Deal!
How to do TRE
Our whole life we’ve been told we need breakfast in order to fuel our brain and body for the day or else we’ll crash and burn. False. We actually evolved to sustain ourselves by utilizing stored body fat to fuel movement and cognition in the absence of external sources of energy.
So…can you guess what the first step is to implement TRE? Skip breakfast and eat your first meal a little later than normal. Note: Water is absolutely fine during your fasting window. The schedule below is designed to help you ease into TRE.
Month 1: 12/12 (12hr fast — 12hr eating window)
- First Bite: 8:00am
- Last Bite: 8:00pm
Month 2: 14/10 (14hr fast — 10hr eating window)
- First Bite: 10:00am
- Last Bite: 8:00pm
Month 3: 16/8 (16hr fast — 8hr eating window)
- First Bite: 12:00pm
- Last Bite: 8:00pm
The “first bite/last bite” times are designed to help keep your eating aligned with your circadian rhythm which can help reduce gut stress and disruptions in sleep so that you wake feeling light, energetic and healthy in the morning. Regardless of your work/life schedule the goal is to eat your calories for the day in a fixed window of time so if you’re a shift worker then adjust as needed but make sure to only eat in your TRE window.
Get After It!
TRE costs $0.00 and does not require you to make any drastic changes to the quantity or quality of food you eat which makes it easy for anyone to implement. In terms of bang for your buck, you can’t beat it. Poor food choices and over-nutrition (eating too much) are detrimental to your health but don’t worry — we’ll optimize those after we dial in TRE.
- TRE — Time-Restricted Eating (TRE) is when you eat all your calories for the day in a fixed window of time (e.g. 8 hours, 10 hours, 12 hours…).
- eTRE — Early Time-Restricted Eating (eTRE) is a method of TRE where you eat earlier in the day and for a shorter period of time (6 hours) in order to align your feeding with circadian rhythms in metabolism.
- CR — Calorie restriction (CR) is a great method for losing weight and improving longevity but can downregulate metabolism, testosterone production and libido.
- TRE + CR — Calorie restriction while implementing TRE can boost fat-loss even more. Just make sure to normalize calorie intake after you reach your desired weight.
- TRE + Exercise — Adding exercise to your TRE program will help maintain muscle and melt away body fat.
- Implementation — The first bite or sip of anything with calories starts your eating window. From here consume all your food for the day within the TRE schedule you choose (e.g. 12/12, 14/10, 16/8).
- Tracking Your Fast- Use a fasting tracker app like ZERO to help you stick to your fasts and shred weight.
GET AFTER IT!
- Effects of 8-hour time restricted feeding on body weight and metabolic disease risk factors in obese adults: A pilot study
- Early Time-Restricted Feeding Improves Insulin Sensitivity, Blood Pressure, and Oxidative Stress Even without Weight Loss in Men with Prediabetes
- Calorie restriction and aging: review of the literature and implications for studies in humans
- Effects of eight weeks of time-restricted feeding (16/8) on basal metabolism, maximal strength, body composition, inflammation, and cardiovascular risk factors in resistance-trained males.
- Brain Metabolism during Fasting