It found that when eight males with prediabetes who were overweight followed early-TRE for 5 weeks, several markers of heart health were improved, including:.

The observed improvements in heart health occured even when the TRE group did not lose weight, and they reported a lower desire to eat in the evening. Researchers need further studies done on more people over longer periods of time to confirm these findings. Accumulating research suggests that TRE has potential, but not all studies show it is more effective for weight loss than daily regular calorie restriction.

A review concluded that intermittent calorie restriction, including TRE, offers no significant advantage over limiting calorie intake each day. More recently, a randomized controlled clinical trial in the New England Journal of Medicine showed TRE had no weight loss benefit after 12 months.

In the trial, people with obesity followed TRE while also eating fewer calories or followed daily calorie restriction alone. When the study ended, there were no differences between the groups for weight loss. Studies from and note that TRE results in equal weight loss to regular daily calorie restriction in people who are overweight or have obesity.

Because of this, it is possible for TRE to be an option for people who want an alternate solution to daily calorie restriction for weight loss. Other research does not show any benefit of TRE for weight loss compared with eating regularly throughout the day with no calorie restriction.

This includes when study participants receive no instruction to change their food choices or activity levels. As the science on TRE for weight loss advances, some researchers have expressed the need for caution around who might consider following TRE.

Among people who are overweight or have obesity, some studies have found that weight loss in TRE may be due to the loss of lean mass muscle versus fat mass adipose tissue.

Therefore, it is especially important for people who are overweight or have obesity and who also have comorbidities such as sarcopenia to talk with a doctor before trying TRE. The current evidence base shows promise for the role of TRE in weight loss in the short term from studies lasting less than 6 months.

However, researchers need longer-term studies with larger numbers of more diverse participants to determine whether TRE can lead to clinically meaningful weight loss that a person can maintain over time.

A study from the journal Appetite aimed to look at the barriers to or facilitators of following TRE over the long term. It used 20 middle-aged adults who were overweight or had obesity and were at risk of type 2 diabetes.

The researchers assessed how easily people could incorporate TRE into daily life following a 3-month study with structured interviews. Seven study participants kept up with their instructions on TRE from the study, 10 adjusted their approach to follow a different version of their original instructions, and three did not follow through with their instructions.

Researchers need more work to understand how TRE influences the biological, behavioral, psychosocial, and environmental facilitators of and barriers to successful long-term weight maintenance.

One study investigated TRE in 11 adults who were overweight. They followed early-TRE for 4 days, where they ate between 8 a. and 2 p. and 8 p.

The authors concluded that when participants followed the early-TRE plan, they had increased activity of mTOR. This is a protein marker thought to be involved in maintaining muscle mass.

A study, in the American Journal of Clinical Nutrition , randomly assigned 16 otherwise healthy males to follow early-TRE for 2 weeks or just regular calorie restriction. It found the TRE group saw an improved ability for their muscle to use glucose and branched-chain amino acids. A study in Scientific Reports assigned 46 otherwise healthy older males to follow 6 weeks of either TRE or their regular eating plan.

The TRE group had no significant changes in their muscle mass. This suggests the participants kept their muscle throughout the study period. In studies that paired TRE with a structured resistance training program, muscle mass was maintained or small gains in muscle health occured:.

The totality of evidence suggests that in combination with resistance training, TRE may improve body composition and help people maintain fat-free mass similarly to non-TRE plans. Some researchers note that TRE may not be the best approach if primary health goals include building muscle mass and improving muscle strength because of the inconsistent eating frequency and nutrient availability for muscles.

However, TRE may be a good alternative for some people who are interested in changing their body composition or losing weight without it being problematic for maintaining muscle mass, growth, strength, performance, or endurance.

Researchers need additional longer and larger studies in different research settings with different populations to better understand the relationship between TRE and muscle health. One of the main advantages of TRE is that it requires no special food or equipment.

However, as with any eating plan, some thought and planning can increase the likelihood of success. The following tips can help to make TRE safer and more effective:. People should start with a shorter fasting period and then gradually increase it over time.

For example, start with a fasting period of p. to a. Then increase this by 30 minutes every 3 days to reach the desired fasting period. Studies have suggested that restricting feeding periods to less than 6 hours is unlikely to offer additional advantages over more extended feeding periods.

It is tempting to start a vigorous exercise plan alongside eating less for faster results. However, with TRE, this can make the fasting period more difficult. People may wish to keep their existing exercise program the same until their body adjusts to the new eating plan. This can help to avoid increased hunger from extra workouts, which may cause burnout or failure.

Hunger can be difficult for people who do not have experience of fasting for several hours each day. Choosing foods rich in fiber and protein during the eating window can help to combat this. These nutrients help a person feel full and can prevent a blood sugar crash or food cravings.

For example, a person may eat whole grain bread and pasta rather than white or refined grains. They can choose a snack that includes protein in the form of lean meat, egg, tofu, or nuts. It is normal to have days where TRE does not work out.

For example, a night out with friends, a special occasion, or a slip-up may lead to people eating outside of their fixed eating window. It is best to see setbacks as an opportunity to get back on track.

The next day, people can recommence the TRE plan and continue toward their goal. For most people, TRE is unlikely to be a miracle weight loss cure. However, studies have shown that it can offer health benefits without a high risk of side effects. It can be a simple way for many people to reduce their calorie intake without complicated or strict diet rules.

Which people, situations, or medical conditions might a time-restricted eating diet suit and why? Time-restricted feeding seems to be beneficial for most people who are not experiencing acute illness or taking medications to lower blood sugar, for type 2 diabetes, for example. Adolescents, young adults, or middle-aged people may all benefit from time-restricted eating if they are only lightly or moderately physically active and are interested in:.

Time-restricted eating may also be beneficial for those who are not successful with daily calorie restriction since some study results indicate that both types of diet yield similar results. the day before. You fast overnight and then all the following day, skipping breakfast and lunch, and then pushing dinner out to p.

for a full 24 hours with no calories. I only recommend this two days per week nonconsecutive. Many people think that the following day they will binge on so much food that the benefits of the fasting on the previous day will be negated, but this is usually not true, especially if you are consciously aware of the risk.

All of these methods are effective, and you can mix and match these as much as you would like. I would highly recommend keeping it flexible. Fast for as long as is convenient on any given day, and break your fast whenever you need to or want to. I think a good goal would be 24 hours per week of additional fasting additional to the standard baseline.

During the fasts feel free to drink ANY noncaloric beverage you want, including but not limited to: water, coffee, tea hot or iced , or any other beverage with no calories. However I would NOT recommend any calories AT ALL, as it takes frightfully few calories to increase insulin and sabotage your fast.

However, I do not routinely recommend this or any other source of calories while fasting, as this may limit some of the benefits of fasting. Once you are properly fat adapted, intermittent fasting can be easy, fun, enjoyable, and liberating—while making you leaner and healthier in the process!

Breakfast every day during the work week is now just black coffee, tea or water, how easy is that? No more worrying about what you are going to grab for breakfast as you rush around in the morning and struggle to get to work on time or get the kids ready for school.

This saves you time, work and effort and is literally a form of metabolic exercise! In the meantime, you are improving your insulin sensitivity and strengthening your fat adaptation. This is a win in many ways. It frees you to eat large and satisfying meals later without feeling the deprivation, without watching calories, and without restricting yourself.

And on days where you skip breakfast and lunch, you will be amazed at how much extra time you have not worrying about what to eat, where to get it, and when to find time to eat it. Your productivity will be higher and you will have more free time. please read our guide on OMAD for more potential benefits and concerns about eating one meal per day.

Intermittent fasting for beginners. Intermittent fasting video course. Ted Naiman, MD and was last updated on June 17, It was medically reviewed by Dr. Bret Scher, MD on April 10, The guide contains scientific references.

You can find these in the notes throughout the text, and click the links to read the peer-reviewed scientific papers. When appropriate we include a grading of the strength of the evidence, with a link to our policy on this.

Our evidence-based guides are updated at least once per year to reflect and reference the latest science on the topic. All our evidence-based health guides are written or reviewed by medical doctors who are experts on the topic. To stay unbiased we show no ads, sell no physical products, and take no money from the industry.

We're fully funded by the people, via an optional membership. Most information at Diet Doctor is free forever. Read more about our policies and work with evidence-based guides , nutritional controversies , our editorial team , and our medical review board. Should you find any inaccuracy in this guide, please email andreas dietdoctor.

Clinical Biochemical Reviews Insulin and insulin resistance. Biochemistry: 5th edition: Section Journal of Clinical Endocrinology and Metabolism Augmented growth hormone GH secretory burst frequency and amplitude mediate enhanced GH secretion during a two-day fast in normal men. Journal of Nutrition Snacking increased among U.

adults between and Diabetologia Hyperinsulinaemia: the key feature of a cardiovascular and metabolic syndrome. Diabetes Global prevalence of type 2 diabetes over the next ten years [review of observational studies; weak evidence].

Medicine Epidemiology of diabetes [review of observational studies; weak evidence]. Endocrinology Review Metabolic Flexibility as an Adaptation to Energy Resources and Requirements in Health and Disease.

Metabolism Metabolic characteristics of keto-adapted ultra-endurance runners. Annual Review of Nutrition Fuel metabolism in starvation. NEJM Increased glucose transport-phosphorylation and muscle glycogen synthesis after exercise training in insulin-resistant subjects.

American Journal of Physiology, Endocrinology and Metabolism Calorie restriction increases fatty acid synthesis and whole body fat oxidation rates. Obesity Early time-restricted feeding reduces appetite and increases fat oxidation but does not affect energy expenditure in humans.

This is based on consistent clinical experience of low-carb practitioners. Diabetes Care Effects of different modes of exercise training on glucose control and risk factors for complications in type 2 diabetic patients [systematic review of randomized trials; strong evidence].

Obesity Reviews The effects of high-intensity interval training on glucose regulation and insulin resistance: a meta-analysis. Medicine Science Sports and Exercise Minimal resistance training improves daily energy expenditure and fat oxidation.

Canadian Journal of Physiology and Pharmacology Glucose metabolism during exercise in man: the role of insulin and glucagon in the regulation of hepatic glucose production and gluconeogenesis. Journal of Applied Physioology Invited review: Effects of acute exercise and exercise training on insulin resistance.

Sports Medicine The exercise-induced growth hormone response in athletes. NEJM Effects of intermittent fasting on health, aging, and disease. This is based on clinical experience of low-carb practitioners and was unanimously agreed upon by our low-carb expert panel. You can learn more about our panel here [weak evidence].

Cell Metabolism Ten-hour time-restricted eating reduces weight, blood pressure, and atherogenic lipids in patients with metabolic syndrome.

The old idea that breakfast is important for health or weight control is mainly based on observational studies, a notoriously weak form of evidence.

When tested this idea does not appear to hold up, at least not for weight loss. A recent meta-analysis of randomized clinical trials found that people assigned to skip breakfast ate less overall and lost more weight than those assigned to eat breakfast daily:.

British Medical Journal Effect of breakfast on weight and energy intake: systematic review and meta-analysis of randomised controlled trials [strong evidence].

International Journal of Environmental Research and Public Health Eat or skip breakfast? The following randomized crossover trial showed no difference in energy expenditure or fat oxidation between 3 and 6 meals per day, but did see a probable increase in hunger with more frequent eating.

This shows a lack of increased metabolism with more frequent eating. Obesity Effects of increased meal frequency on fat oxidation and perceived hunger. Research suggests that when obese people fast, hormonal changes occur that lead to a decrease in total body protein breakdown, which includes muscle:.

In a randomized, controlled study, obese adults were assigned to either fast every other day or eat a calorie-restricted diet every day. Those in the intermittent fasting group showed less slowing in metabolic rate during the 8-week study and greater improvement in body composition after 32 weeks of follow up compared to people in the calorie-restricted group:.

Obesity Silver Spring A randomized pilot study comparing zero-calorie alternate-day fasting to daily caloric restriction in adults with obesity [moderate evidence].

These other studies likewise show an increase, or at least no decrease, in metabolic rate of metabolism.

American Journal of Clinical Nutrition A controlled trial of reduced meal frequency without caloric restriction in healthy, normal-weight, middle-aged adults [moderate evidence].

American Journal of Clinical Nutrition Resting energy expenditure in short-term starvation is increased as a result of an increase in serum norepinephrine [weak evidence]. This is based on consistent clinical experience of low-carb and lifestyle practitioners.

In addition, studies show very low carb diets reduce hunger, which in theory could make fasting easier. Obesity Reviews Do ketogenic diets really suppress appetite? A systematic review and meta-analysis. Journal of Nutrition Dietary fiber and energy regulation. International Journal of Obesity Related Metabolic Disorders Effect of an acute fast on energy compensation and feeding behaviour in lean men and women.

Studies also have not show if breaking a fast is an all-or-none event or if reduced caloric intake in the morning can still mimic many of the benefits of time restricted eating. Some people find that a little fat in the morning helps them maintain a longer fast, where as in the absence of that fat they cannot maintain a fast.

This clearly varies from person to person. Low carb for beginners All guides Foods Visual guides Side effects Meal plans. Keto for beginners All guides Foods Visual guides Side effects Meal plans.

Switching from this style of eating to time-restricted eating may cause you to naturally eat less. However, you do need to be careful, as some people do not actually eat fewer calories during time-restricted eating.

Whether or not you will experience weight loss with time-restricted eating probably depends on whether or not you manage to eat fewer calories within the eating period.

If this style of eating helps you eat fewer calories each day, it can produce weight loss over time. If this is not the case for you, time-restricted eating may not be your best bet for weight loss. Several substances in your blood can affect your risk of heart disease, and one of these important substances is cholesterol.

In calls, it serves important functions such as becoming part of the cell membrane. When participants lost weight with time-restricted eating, their cholesterol improved. When they did not lose weight, it did not improve.

Having too much sugar in your blood can lead to diabetes and damage several parts of your body. Overall, the effects of time-restricted eating on blood sugar are not entirely clear. Time-restricted eating is very simple — just choose a certain number of hours during which you will eat all your calories each day.

If you are using time-restricted eating to lose weight and improve your health, the number of hours you allow yourself to eat should be less than the number you typically allow.

For example, if you normally eat your first meal at 8 a. and keep eating until around 9 p. To use time-restricted eating, you would reduce this number.

For example, you may want to choose to only eat during a window of 8—9 hours. This essentially removes one or two of the meals or snacks you usually eat. However, most people use windows of 6—10 hours each day.

Following an early time-restricted eating schedule may offer the most benefits in terms of weight loss and metabolic health. However, it's important to pick a schedule based on what works for you and your lifestyle and what you're most likely to follow.

Time-restricted eating has been shown to support weight loss in several studies. Of course, it's best to pair time-restricted eating with a nutritious, well-rounded diet and regular physical activity to maximize your results.

Time-restricted eating is a flexible eating pattern that may offer benefits in the long run, including increased weight loss and improved metabolic health. Additionally, there are several variations available, making it easy to incorporate TRE into your schedule.

However, TRE isn't a good fit for everyone and may be associated with negative side effects, some of which can be serious. For this reason, it's best to talk to your doctor to see if TRE is worth a try and how it may impact your health.

If you do decide to try TRE, these tips can make it easier to follow. Skip to Content. Shop Health Coaching Classes Editor's Picks Beauty Food Healthy Weight Login Login. Login Login. This ad is displayed using third party content and we do not control its accessibility features.

Close Banner. Integrative Health expert reviewed. Author: Rachael Ajmera, MS, RD. By Rachael Ajmera, MS, RD. Registered dietitian.

Rachael Ajmera, MS, RD is a registered dietitian and writer based in San Francisco. She holds a master's degree in Clinical Nutrition from New York University and an undergraduate degree in Dietetics. Lauren Torrisi-Gorra, M. Registered Dietitian. Lauren Torrisi-Gorra, MS, RD is a registered dietitian, chef, and writer with a love of science and passion for helping people create life-long healthy habits.

What is TRE? What is time-restricted eating? Summary Time-restricted eating TRE involves restricting the number of hours a day that you eat food—usually to a six- to hour window.

There aren't typically restrictions on what you can eat during your feeding window. Benefits of TRE. It can enhance longevity by promoting cellular repair and autophagy. It can promote weight loss via calorie restriction. It might help with blood sugar regulation.

Research-backed tip: Pairing TRE with exercise might even amplify the metabolic benefits. A study found that limiting food intake to less than 10 hours per day and participating in three sessions of high-intensity interval training HIIT per week improved hemoglobin A1c , a marker of long-term blood sugar control, and decreased body fat more significantly than either TRE or HIIT alone.

Sample schedules. Early eating:. Black coffee or tea no milk, cream, or sugar 7 a. Veggie omelet with whole wheat toast 10 a.

Greek yogurt with fresh fruit and walnuts 12 p. Baked chicken with quinoa and broccoli End at 3 p. Sesame tofu chopped salad. Midday eating:. Below is a sample meal plan for this TRE schedule:. Black coffee or tea no milk, cream, or sugar 11 a. Frittata with spinach and tomatoes 2 p.

Burrito bowl with healthy protein and fajita veggies 4 p. Hard-boiled egg End at 7 p. Salmon with brown rice and asparagus. Late eating:. Late TRE generally requires you to skip breakfast and eat a late lunch. If you're interested in trying late TRE, here's a sample schedule:.

Black coffee or tea no milk, cream, or sugar 2 p. Sandwich or wrap with side salad 5 p. Chia pudding with berries and nut butter 7 p. Pasta with vegetables End at 10 p. Lentil soup. How to choose your ideal TRE window. Summary Early TRE stopping eating in the late afternoon is the most effective time window for weight loss and metabolic health, but it can be difficult to stick to.

Ultimately, the best TRE window for you will be the one that fits into your lifestyle. Side effects and safety. Dizziness Lightheadedness Extreme hunger Weakness Headache or migraine Fast heartbeat Heart palpitations Fainting Loss of consciousness.

Frequently Asked Questions.