The popular time-restricted feeding diet, otherwise known as TRF, has gained in popularity over the past few years. Now more than ever, as research [1] shows the benefits of time-restricted feeding, the trend continues to grow. If you're feeling a bit overwhelmed about what the TRF diet entails or whether it's even right for you, look no further; we've got all the answers!
What Is TRF?
Time-restricted feeding is when you limit the number of hours during which you will consume calories. In TRF, you can abstain from food anywhere from eight hours all the way to 24 hours. According to Harvard-trained physician and author of The Paleovedic Diet Dr. Akil Palanisamy [2], it's good to start off slowly. He explained to POPSUGAR that "eating during a 10-hour window during the day and then fasting for 14 hours is probably the easiest way to start. That can then be increased to eating during an eight-hour window and fasting for 16 hours daily."
Benefits of TRF
Dr. Palanisamy is a proponent of TRF and elaborated on the possible benefits. He described how time-restricted feeding " . . . really is a variation of intermittent fasting [3] and has all the same benefits in terms of reducing inflammation, improving metabolism, promoting weight loss, decreasing body fat, reducing the risk of cancer, and having antiaging benefits. The premise is the same — it's not just what you eat but when you eat that is extremely important."
We spoke with Dr. Josh Axe, founder of DrAxe.com [5] and cofounder of Ancient Nutrition, to further explain who exactly TRF could benefit. He described how "based on results in numerous animal and human studies, time-restricted feeding could potentially be useful for people at risk for diseases like diabetes, cancer, heart disease, neurodegenerative disease, rheumatoid arthritis, and asthma. It also helps fight obesity and can assist people in shedding stubborn pounds. It's already a commonly researched practice in the field of brain and body longevity, as it seems to aid the body in kick-starting the natural processes of healing and rejuvenation. Some studies report TRF has reduced the incidence and severity of seizures — in some cases, it is as or more effective as some seizure-reducing drugs." So clearly, the trend has some staying power because of the numerous health benefits [6] of time-restricted feeding.
Side effects of TRF
Dr. Axe described to POPSUGAR some of the side effects that may occur when you first start time-restricted feeding. He explained, "A few [side effects] are not surprising: bloating, hunger pangs, digestive distress, and weakness or a lack of energy. In multiple-day total fasting (consuming no calories for an extended period of time), these may be magnified by the 'carb flu,' the process of your body transferring to ketosis [7], when it can no longer feed on glucose for energy. Others report temporary brain fog as their body adjusts, as well as heartburn, headaches, and even potential caffeine dependency (when coffee satiates hunger during fasting periods)." So it's important to be mindful of the side effects and practice TRF cautiously.
Dr. Palanisamy also went into detail about how TRF can cause stress on the system. He explained to POPSUGAR, "Any type of intermittent fasting including the TRF diet is a type of stress on the system. There are positive types of stress ('eustress') that then lead to beneficial changes in the body through the mechanism of hormesis. However, if someone is already under extreme stress, then adding fasting to the equation might have a negative impact on their body and not trigger fat burning like it normally would in other people." Meaning, make sure you're not going through any rough patches when you start TRF because of the added stress your body will take on.
Is TRF Right For You?
Dr. Palanisamy cautioned, "It is important to know that this diet is not for everyone. Patients with hypoglycemia or issues with low blood sugar may find it challenging. They should avoid it until their blood sugar is better managed. For patients with high blood sugar, this diet approach may actually be very helpful. Any person who is obese or struggling to lose weight could find this approach to be very effective." He continued by also warning that "anyone with hormone imbalances, especially of the adrenal gland or thyroid, should also be cautious with the TRF diet, because their bodies will already be experiencing stress as a result of this."
Dr. Axe also urged women to be observant of any hormonal changes while doing TRF. He explained that "women sometimes experience negative hormonal changes in certain models of TRF, such as the popular 16/8 schedule. Instead of daily fasting, women seem to benefit most from a crescendo style of TRF, following something like a 5/2 schedule where fasting for 12-16 hours happens no more than two to three times a week." So whether you decide to try out TRF or not, make sure you talk to your doctor if you have any health concerns and start off moderately!