Time-restricted feeding is a type of intermittent fasting in which feeding times are restricted to certain hours of the day. Actually, this should be our natural pattern for eating — eat some food, feel satisfied then stop, get some sleep, rest, work, and repeat.
If you think about it, before all the dieting trends started we didn’t think so much about food and when we are eating our next meal.
Now, for most people, when they’re eating their next meal, and what they should eat or not eat to avoid gaining weight is on their mind most of the time. We are really not giving our bodies enough time to digest what we eat. Scientists have now found that actually the way our ancestors ate was correct.
Reducing energy intake, i.e. how many calories we eat, on a daily basis may allow the fasting physiology to be triggered sooner and to be sustained for longer periods of time than when we’re consuming standard or excessive amounts of calories.
Similarly, restricting the timing of food intake to a few hours with TRF, without especially trying to reduce caloric intake, can also trigger the fasting physiology after just a few hours of fasting.
Fasting is a very important factor in optimizing our lifespan (repair and rejuvenation) and health span, and different forms of fasting (and fasting mimicking) diets have a huge potential of being integrated into our standard medical care for the prevention and treatment of chronic metabolic diseases.
Examples of forms of fasting can include TRF, feeding every other day (alternate day fasting), adopting a reduced calorie regimen twice a week (5:2 fasting), or undergoing a periodic cycle of diets that provide a relatively high caloric content but are able to mimic many of the effects of fasting (Fasting Mimicking Diets). I will talk more about Fasting Mimicking Diets in one of my next articles.
Satchidananda Panda, Ph.D. is a professor at the Salk Institute, and a leading researcher in TRF. He found that by eating following our body’s own circadian clock, which guides us to when to eat, sleep, rest or work, can repair brain wave activity and improve hormone production, cell regeneration and other biological activities linked to this daily cycle. Every organ has its own internal clock, too.
For example, in our liver it controls many of the biological processes storing food molecules when we eat a meal, then mobilizes nutrients when we fast during sleep.
Disturbing this cycle for prolonged periods can lead to development of abnormal physiology, such as obesity and diabetes. On the other hand, Dr. Panda discovered that when we follow a restricted feeding window of just 10 to 12 hours each day, and only consume water during the other hours of the day, we can improve or even reverse obesity, pre-diabetes, and even type-2 diabetes.
Dr. Panda explains: “A section of the hypothalamus called the suprachiasmatic nucleus (SCN) lies at the center of the body’s master clock and gets input directly from light sensors in the eyes, keeping the rest of the body on schedule. The circadian clock even mediates the immune system.
Mice with a crucial circadian molecule missing had higher levels of inflammation in their bodies than other mice, suggesting that genes and molecules involved in the circadian clock could be drug targets for conditions linked to inflammation, such as infections or cancer.”
The sleep hormone melatonin is produced by the pineal gland in the brain, and levels are typically very low during the day and reach their peak at night. Melatonin actually inhibits the production of insulin, a hormone secreted by the pancreas. When melatonin activates these receptors, insulin secretion is decreased. So it seems to be a good idea to stop eating at least two to three hours before we go to bed.
TRF can also improve blood glucose control and blood pressure while resting our guts, and thus might be useful for inflammatory bowel disease (IBS) and acid reflux.
It seems so easy to apply, however when you give enough attention you will realize actually how much, or how little time we are giving our body to rest, digest, and replenish.
You may like to start at first with simply not eating during a 10 to 12 hour window each day — a lot of that time you will be sleeping, so just stopping eating a little earlier before you sleep, and starting a little later after you wake up, will let you comfortably reach 10 to 12 hours. You can then gradually increase your fasting window, and monitor how you feel as well.
You can get more information at mycircadianclock.org, you can even join their free research studies there too.
So to sum up, can when you eat actually be be more important than what you eat? It certainly looks possible. Of course, this is not to encourage you to start eating fast-food every day!
Ayda Ersoy is a nutrition and fitness director at The Diet Doc Hawaii. She can be reached at DietDocHawaii.com, Ayda@DietDocHawaii.com or (808) 276-6892.