May 1, 2021

Time Restricted Eating

“Time restricted eating is not healthy, it’s just cutting calories.”

“Intermittent fasting is just starving yourself, there is no research to support this concept.”

Have you heard this before? I disagree. Here’s why…

Time restricted eating was never about cutting calories, it’s all about eating within the body’s natural circadian rhythm. We now know that our organs have a cycle of when they are supposed to slow down for the night, and if we are continually eating during this phase we make them keep working leading to weight gain, loss of sleep and disease.

Nutrition is based on two concepts.

The first concept is that if you have two people on the same diet, the person eating less calories will lose weight. This is why counting calories is extremely popular.

The second concept, which has been repeated thousands of times in a lab setting, is that if you feed two identical mice the same calories but one gets a balanced ratio of carbs, fat and protein and the other gets just carbs and fats, the one who is eating carbs and fat will not only gain more weight but will start to develop diabetes. This is part of the reason the “fat is bad” for you myth started, however that’s a story for another day. This tells us that the quality of food is extremely important, aka not all calories are created equal.

There should be a third concept of nutrition – the timing of eating. In 2012, a researcher named Satchin Panda PhD was very interested in circadian rhythm of not only mice but the organs as well. They took two genetically identical mice and gave them the exact same high fat diet. One group had full access to the food throughout the day and the other group was restricted to an 8 hour window. The mice who were eating in a smaller window soon learned to eat the exact same number of calories as the mice eating throughout the day. The mice eating the high fat diet throughout the day developed metabolic diseases as expected (this has been done over 10,000 times) however, the mice eating within an 8 hour window, the same diet and the same calories were completely healthy and had normal blood sugar levels and cholesterol levels. These benefits continued for mice throughout a full year or more which is equal to much longer in humans. Timing of eating made all the difference, not the calories or the food content. The most amazing part of this study was that the mice who had developed disease from eating all day long reversed the disease when they went to an 8 hour eating window.

Eating windows are measured from the time you have your first bite of food in the morning until you have your last bite before bed. The most benefits researchers found happened when all food was consumed within an 8-11 hour window. But there were benefits all the way up to 14 hours, at 15 hours was when things went downhill. A 15 hour eating window looks like someone eating right when they wake up at 7 AM and then having their last snack or drink before bed at 10 PM, not too uncommon.

This has been repeated many times with humans as well. One study took two groups of people all who had a BMI over 25 and had them eat in a 14 hour window and a 10 hour window. They didn’t tell them what to eat, just when to eat. The group who ate in a 14 hour window saw no changes, however the group that ate within a 10 hour window lost 4% of their bodyweight over a 4 month period. This was all without any change in nutrition or calories, just a change in eating patterns.

On top of all this research is now finding that our organs actually have a circadian rhythm as well and it’s set by when we eat food. For example our pancreas releases insulin to help with our blood sugar. 2-3 hours before bed our sleep hormone melatonin starts to rise. Research shows that melatonin actually inhibits the release of insulin from our pancreas. This means that if you are eating a few hours before bed your blood sugar is going to be less regulated and more fat is going to be stored.

Time restricted eating is the missing key for many people. Not only can it be beneficial for weight loss, but also a health benefit for your organs.