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Limiting food intake with time does it work?

A new study examines whether if eating time-constrained can have positive health benefits. AleksandarNakic/Getty Images

• The results of animal research have revealed significant advantages to metabolism from restricted diets.
• Human studies have suggested that these results could be useful to humans.
• A recent study takes a look at the evidence from animal and human studies.
• The authors recommend more study is needed to determine the ways in how restricted eating habits can be beneficial and achievable for humans.

Researchers have reviewed the evidence to support those health advantages of eating a time-restricted diet -this is a variant of intermittent fasting that requires people to consume food only within the same time period each day.

The review, which is released in the Journal of the Endocrine Society, Endocrine Reviews researchers looked into studies on animals as well as the first human studies. They found evidence to suggest that limiting time eating habits can aid in the prevention and treatment of many chronic metabolic diseases.

They do insist on additional substantive studies in order to show the positive effects of a time-restricted diet on food consumption in humans, and to uncover the mechanisms at the root of these benefits.

Circadian rhythm

The concept of time-restricted eating has drawn significant attention from researchers in the past few years. When eating is restricted because of the duration of time, people typically consume their usual food but only for a set time period each day. It can be anything from 6 to 12 hours.

Scientists have proved the advantages of eating food that is time-restricted, mostly for mice, in research. There are also numerous trials with human participants which have shown promising results.

The writer who is connected to Professor. Satchidananda Panda from the Regulatory Biology Laboratory at the Salk Institute for Biological Studies in San Diego, CA, interviewed Medical News Today. He stated that time-restricted eating studies on animals have revealed the potential health benefits of eating foods that are time-restricted.

"Animal studies so far have revealed that eating restricted for a certain amount of time affects various organs, and even the microbiome of the gut in a positive way. Numerous pathways and molecules associated with metabolic disorders, like prediabetes and diabetes, adiposity [...], fat liver disease, as well as certain cancers, are controlled in a positive manner by eating with a time limit," said Prof. Panda.

According to the authors of the most recent review one of the primary benefits of a strictly controlled diet is the ability to help individuals regain their disturbed circadian rhythm.

Circadian rhythms comprise a variety of bodily functions that take place over the course of a 24-hour periodTrusted Source. Professor. Panda and his colleagues have observed that circadian rhythms evolved because of changes in temperature, light and humidity as well as the availability of nutrients during the cycle of the earth's night and day cycles.

In the event that someone has a disruption in their circadian rhythm and is prone to suffering from a variety of health problems that include cancers, metabolic disorders, issues with the hormones, the immune system and reproductive issues.

Modern living habits change the rhythm of the circadian cycle in various ways. According to Prof. Panda and his colleagues 40% of people are employed, taking care of people, and socializing in the late hours. This leads to the circadian rhythm to be disturbed.

In the cycle of the clock and in fasting

The main cause of the disturbance may be an increase in consumption of food in excess of the amount that your body is used to, in line with your circadian rhythm. It occurs when you are sleeping and not during daytime.

Professor. Panda and his colleagues mention their research findings that show that circadian cycles that are connected to peripheral organs and most of our brains are specifically affected by the timing of eating.

Then, a restricted eating , with a limit on time which includes the fasting time could aid in supporting cycles of circadian rhythms. It could also reduce the possibility of negative health effects that an imbalanced circadian rhythm might bring about.

Professor. Panda and his coworkers are also highlighting the way research on mice shows that eating a restricted diet can lessen fat tissue in the abdomen and improve gut health.

Researchers have noted that there are few human studies investigating the advantages of eating an calorie-controlled diet. The first results of these studies support the positive results observed in animal models. These include the reduction in body weight and the waist circumference of the waist as well as the Body mass index.

Professor. Dorothy Sears from the Division of Endocrinology and Metabolism at the University of California San Diego School of Medicine also was interviewed by MNT..

Professor. Sears has a wealth of knowledge in the eating habits of people who are time-bound in addition to the circadian cycle. She stated she believes the work of Prof. Panda and his colleagues have conducted research that "is a thorough review article that summarizes the accumulating evidence that alignment of food intake with the body's biological rhythms promotes health."

Ideal eating window?

The research currently being conducted offers a hint of the ideal time of day to reduce how much food eaten.

Interview with MNT in an interview with MNT, Professor. Panda said "The human studies have tested 4-, 6-, 8-, 10-, and 12-hour time-restricted eating, and these studies show some dose responses."

"Four- and 6-hour time-restricted eating can have many benefits among [people with overweight and obesity], but it also reduces quality of life due to its adverse effects on feeling excessive hunger, dizziness, headache, and nausea, etc."

"Eight- and 10-hour time-restricted eating windows are well tolerated, yield several benefits, and people voluntarily adopt such practices long term. "

"Twelve-hour time-restricted eating may not produce immediate benefits within a few months, but we do not know in the long term if it could impart some benefits."

According to Professor. Sears, "There is insufficient research evidence that supports any particular regimen, e.g., best time of day to start/stop eating or how many 'eating' hours per day."

"Promising evidence from Dr. Panda's lab in mice supports that an occasional 'day off' from time-restricted eating, or eating at night may still confer benefit in humans," Professor. Sears.MEDICAL NEWS Today's NEWSLETTERKnowledge can be power. Join our daily newsletter for free.

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However, Professor. Panda said to the MNT that certain individuals must consult with a doctor before beginning a diet with a time limit.

"Most people and their caregivers believe that it's safe for everyone from teens to seniors to eat a restricted diet for 12 hours every day. Time-restricted eating for ten hours is possible for those who do not suffer from a chronic illness," prof. Panda.

"For those suffering from type 1 diabetes or type 2 diabetes and other chronic diseases restricted eating for 10 hours or less [...] might require medical supervision to prevent hypoglycemia or medication adjustments. In the same way, those with other chronic illnesses should consult their doctor prior to starting eating for 8 or 10 hours. eating."

"Time-restricted eating for 6 or 4 hours is not recommended for the majority of people. A short time frame for eating could also result in a significant reduction in the daily intake of calories or the consumption of specific macro- or micronutrients. This type of restricted eating for short periods of time may be unsustainable over the long run," advised Prof. Panda.

Prof. Sears confirmed this by saying in an interview with the MNT that "overall the time-restricted diet appears to be safe for the majority of people, not just those suffering from type 2 diabetes. ."

"Some patients report minor temporary side effects like lightheadedness or nausea. Due to the limited studies, self-reported compliance and the variety of regimens further research is required to evaluate these effects fully."

"People with conditions that impact metabolism -- for example, thyroid disorders, diabetes, and pregnancy -- should consult their healthcare provider before starting a regimen that includes fasting for longer than overnight," suggested Prof. Sears.

Future research

Professor. Panda said to MNT that scientists must undertake more research to better know the advantages of restricted time for the consumption of food for animals and human beings.

"Most restricted eating studies were conducted on male mice in their early years. We need to extend these studies to include both genders as well as older mice."

"Many benefits of eating restricted in time point to changes in the molecular structure of multiple organs, yet we don't know the nature of those changes. Therefore, more in-depth molecular studies across multiple organs are required to gain a better understanding of the mechanisms of eating restrictions on time."

"Although time-restricted eating may appear easy to adopt, many find it difficult [...] So implementation research on finding personal, interpersonal, cultural, work-related, and societal barriers to adopting time-restricted eating [is] needed," Professor. Panda.

Professor. Sears More extensive study, more rigorous studies are needed to better understand what is the best way to use the time-restricted diet.

Professor. Sears explained"that "randomized controlled trials that are large in sample size are essential to accurately assess different times of food intake and the related health effects. The majority of controlled randomized studies have been limited to very few people, and therefore, the results from these studies are not reliable."

"There are several large trials now funded by the National Institutes of Health and the Department of Defense to test benefits of circadian-aligned food intake timing," explained Professor. Sears. "Results from these should be illuminating and provide more statistically robust interpretations to guide public health recommendations."