Time Restricted Eating
Updated: Feb 10
Time restricted eating is the research done by Dr. Satchin Panda of the Salk Institute looking at restricting eating based on circadian biology. His studies showed that eating only during daylight hours not only caused a reduction in weight but also decreased fat, increased muscle mass and increased endurance.
Panda found that mice which ate within a set amount of time resulted in slimmer, healthier mice than those who ate the same number of calories in a larger window of time. This study highlights that it is when one eats that is more important than what one eats. Human studies confirmed the animal studies and were presented at The Obesity Society’s annual meeting.
Why is it important to restrict eating during daylight hours?
Our circadian rhythm manages biological functions like cellular repair and hormone signaling.
Your liver metabolizes glucose during daylight hours and is strongest during the morning and weakens during the evening.
Time Restricting Eating did not affect how many calories participants burned but increased fat burning for several hours at night and improved metabolic flexibility, which is the ability to switch between burning carbs and burning fats.
Cells are much more sensitive to insulin during the day and less so at night. This is because melatonin will inhibit the release of insulin from your pancreas. Melatonin is not only a brain hormone, but most is made in your gut from Serotonin. Gut melatonin goes directly to the pancreas and modulates the secretion of insulin. Melatonin is secreted in most people 3 hours before you go to bed.
How to incorporate time restricted eating?
The circadian clock starts when you consume anything other than water. Even black coffee will activate the clock genes in your liver.
Stop eating after 12 hours. i.e. If your first cup of coffee or tea is at 6am, stop all eating and drinking at 6pm (except for water). For two days a week, try a shorter eating window of only 10-8 hours. If your first cup of coffee is at 6am, then you should stop eating at either 2 or 4.
Do not skip breakfast and make lunch your biggest meal of the day. You do not want to start your clock at noon, so you can eat dinner later in the evening. This goes against your circadian biology when our body is shifting toward sleep as the sun goes down.
Time restricted eating is NOT the same as intermittent fasting. Intermittent fasting does not account for circadian biology and simply follows a long fasting period of 12 hours or more. Most people who employ intermittent fasting will skip breakfast and eat larger meals later in the day. In the evening your metabolism of glucose is less active, and your cells are less sensitive to insulin. You will not receive the same results as time restricted eating.