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How You Can Reverse Prediabetes By Timing When You Eat

You can reverse prediabetes by timing when you eat

The science shows that you can reverse prediabetes by timing what you eat. Why should you care? Because, as you'll soon see, there's a good chance that you're prediabetic, or have higher blood sugar than is healthy. If that's the case, you're in the danger zone, given that long-term health requires low and stable blood sugar levels, as you'll soon see.

There are many ways you can eat on an intermittent basis, as opposed to eating all day long and into the night. New research shows that such time-restricted feeding improves insulin, blood pressure and oxidative stress biomarkers, leading to a healthier, and perhaps longer life.

The good news is that restricting the time frame within which you eat is simpler than adhering to a diet, and perhaps more effective too. Let's delve deeper into this subject, first by learning why your blood sugar level is so important, the positive time restricted eating can have on blood sugar and why when you eat often times is more important than what you eat.

For most of us, our blood sugar is too high, which can be corrected by time restricted eating.

The Blood Sugar Problem

About 86 million Americans are prediabetic, says WebMD, meaning that their blood sugar level is higher than it should be -- dangerously high -- but not yet in the diabetes range. The CDC reports that more than 100 million Americans have prediabetes and diabetes. Given a population of around 320 million, that means that just below one of every three Americans have a sugar/insulin resistance problem, and it's not going away.

For both people in the U.S. and the rest of the world, the prevalence of prediabetes is increasing. Experts have projected that more than 470 million people will have prediabetes throughout the world by 2030 [1].

OK, so a lot of people have some sugar in their blood; why panic about that?

Well, let's take a look at some sugar numbers as presented by WebMD and the Life Extension Foundation (LEF). WebMD determines normal, prediabetes and diabetes levels using a general reference range representing the U.S. population, which are also the numbers your doctor would most likely adhere to.

Fasting plasma glucose test:

  • Normal if your blood sugar is less than 100
  • Prediabetes if your blood sugar is 100-125
  • Diabetes if your blood sugar is 126 or higher

Hemoglobin A1C (or average blood sugar) test:

  • Normal: 5.6% or less
  • Prediabetes: 5.7 to 6.4%
  • Diabetes: 6.5% or above

Based on its review of the pertinent research, The Life Extension Foundation thinks that the above blood sugar/glucose categorizations for normal, prediabetes and diabetes advocated by WedMD are too lenient.

LEF says that your risk for age-related chronic disease is far greater at these "normal levels" than has been previously recognized, and put the ideal fasting glucose should range between 70 and 85 mg/dL (3.9 – 4.7 mmol/L). (Go here for blood glucose conversion table.)

One team of researchers found that the risk of developing diabetes itself was increased more than seven-fold in people with fasting glucose levels of 105-109 mg/dL, compared with people with fasting glucose levels less than 85 mg/dL, says LEF, and point to the following risks associated with "normal" blood sugar levels [2]:

Increased Health Risks in People with "Normal" Glucose Levels


Glucose Levels (mg/dL)

Increased Risk

Developing Type 2 Diabetes


Up to 283%

Stomach Cancer


Up to 130%

First-time Heart Attack

Above 88


Need for Coronary Bypass or Stent Procedure

Above 95


If you accept LEF's summary of the research marking 85 mg/dL as the highest acceptable fasting glucose, then I'd be willing to bet that your number is too high, if you want optimum health.

If you wish to optimize your health, the work of two research scientists will be of interest: Dr, Drew Duglan's work on Intermittent Fasting (IF), and Dr. Nimet Maherali's work on time-restricted eating. Let's examine each of these.

Reverse Prediabetes With Time Restricted Feeding

Prediabetes can be reversed by restricing the time frame within which you eat

Drew Duglan, PhD. did his doctoral research on the cardiovascular implications of diabetes at Oxford University. He says that you can reverse prediabetes and diabetes as well by restricting the time window in which you eat, particularly if you do so earlier in the day to match your circadian rhythms.

Dr. Duglan arrives at this conclusion through a review of a rigorous, 5-week randomized crossover feeding trial on eight prediabetic men conducted by scientists at the University of Alabama, Birmingham. Participants in this study were asked to adopt one of two eating schedules:

  1. Early Time Restricted Feeding (eTRF) schedule consisting of a 6-hour eating window, wherein the last meal was consumed before 3:00 PM each day; or
  2. A 12-hour eating schedule.

After a seven week break, each participant switched over to the other schedule. The researchers wanted to gauge whether intermittent fasting has benefits independent of weight loss. Therefore, food intake and meal composition was matched across both eating schedules, and each participant was fed enough food to prevent any reductions in body weight.

Compared to participants on the 12-hour schedule, those on eTRF experienced four important biomarker improvements (the first two pointing to both insulin sensitivity and β-cell responsiveness):

  • A decreased fasting insulin,
  • A decreased level of insulin during an oral glucose tolerance test,
  • A significant decline in systolic and diastolic blood pressure equal to anti-hypertensive medications, and
  • Reduce levels of 8-isoprostane, a marker of oxidative stress.

I stress that these improvements happened when compared to a relatively small duration of eating cycles -- 12 hours; whereas, most of us eat and drink something from the moment we arise till we go to bed, a time period well in excess of 12 hours.

What about hunger?

A common critique of most TRF protocols is the assumed increase in hunger during the longer fasting periods. Let's face it, if you're hungry all the time, you won't do it. In this study, however, participants on the eTRF schedule scored lower on most subjective measures of evening appetite, such as the desire and capacity to eat, while ratings of satiety increased.

Interestingly, subjects actually reported that eating all their food within a 6-hour period was a greater challenge than enduring the 18-hour fast, highlighting the feasibility of these interventions in future settings inside and outside of the laboratory.

The role of your circadian clock

The study we've been examining wasn't just about assessing the health benefits of reducing a person's feeding window, but also when the feeding occurs - it incorporated both fasting and biological rhythms.

We each have many so-called circadian clocks that regulate metabolism in response to different nutrients and based on the timing of food intake. In a paper called, Circadian clocks and insulin resistance, Dr. Dirk Jan Stenvers and his collaborators investigated the effect such "clocks" have on our biology and health.

The circadian timing system consists of a central brain clock in a part of your brain called the hypothalamic suprachiasmatic nucleus, as well as in various peripheral tissue clocks.

The circadian timing system is responsible for the coordination of many daily processes, including the daily rhythm in human glucose metabolism. The central clock regulates food intake, energy expenditure and whole-body insulin sensitivity, which are fine-tuned by local peripheral clocks.

For instance, the peripheral clock in the gut regulates glucose absorption, peripheral clocks in muscle, adipose tissue and liver regulate local insulin sensitivity, and the peripheral clock in the pancreas regulates insulin secretion.

Misalignment between different components of the circadian timing system and daily rhythms of sleep–wake behavior or food intake as a result of genetic, environmental or behavioral factors might be an important contributor to the development of insulin resistance. Specifically, clock gene mutations, exposure to artificial light–dark cycles, disturbed sleep, shift work and social jet lag are factors that might contribute to circadian disruption.

The point of all of this clock business is that food timing matters. As the Professor of Regulatory Biology Laboratory at the Salk Institute, Dr. Satchin Panda puts it:

"When you eat is more important than what you eat."

Key endocrine functions such as insulin secretion and insulin sensitivity appear to be optimal in the morning, suggesting that concentrating food intake within the earlier daylight hours is superior for circadian alignment.

Which is what the second research scientist I mentioned above, Nimet Maherali, PhD, discovered in her work, as you'll learn about next.

To Reverse Prediabetes, Stop Eating Earlier

You can reduce your blood sugar, perhaps even reverse prediabetes, by not eating late into the evening.

In her first-hand account, Dr. Nimet Maherali - who has studied diabetes at Harvard University and is developing a therapy for type 2 diabetes. - describes how she had more to learn about controlling and even reversing this disease through a Time Restricted Eating (TRE) approach.

She had great motivation for this work - she found out that she's prediabetic!

It happened to Dr. Maherali like it does to most of us whose harried, unquestioned lifestyle leads to insulin insensitivity and prediabetic blood glucose numbers. She gradually became overweight and ate whenever she could as she strenuously applied himself to her profession.

Dr. Maherali TRE Protocol

Once she was diagnosed as prediabetic, Dr. Maherali became determined to improve her blood glucose numbers and insulin sensitivity. She remembered the name of a researcher, Satchin Panda, whose research showed that the timing of food intake has important consequences for metabolic health.

Two studies on this caught her attention:

  1. Mice given food during active/waking hours are metabolically healthier compared to mice given food during sleeping hours. [3]
  2. Mice exposed to food for 8 hours a day versus 24 hours a day are protected from obesity and metabolic disease, despite consuming the same number of calories. [4]

It wasn't clear to her whether this protocol could be applied to reversing insulin resistance in humans, but the underlying mechanism made sense, and it seemed worth trying. She decided to limit his food intake to an 8-hour window each day, with no change in food type or quantity.

Dr. Maherali didn't specify when her feeding window began each day, but said it ended at 8:00 PM; the math then suggests she began eating at noon. In three days her fasting blood glucose levels to return to normal, but her average glucose test — the HbA1c — remained at the prediabetic level of 6.1%

Nervous, she contacted Dr. Satchin, who suggested to two things:

  1. Further cut the feeding window from eight hours (12:00 PM to 8:00 PM) to six or seven hours, and
  2. Eat oats and lentils to help with the longer fasting times, given that they're both satiating.

Dr. Maherali did change her TRE plan, but not by reducing the feeding window to under eight hours. What she did is to do all his eating earlier in the day, between 10:30 AM and 6:30 PM. In addition, she restricted all refined carbohydrates – no added sugar, no bread, no potatoes, no pasta, no rice, no processed fruit juice.

Her TRE Challenges

Dr. Maherali faced two challenges on his TRE program:

  1. Eating enough food during the given time window. She addressed this being mindful that she not become so distracted by work and the events of his life that he didn't eat enough during her feeding window.
  2. Being ravenous during the second week on TRE. She dealt with this by drinking water and after six weeks, became accustomed to the protocol.
Her Health Improvements from TRE

After two months on TRE with no refined carbohydrates:

  • Weight loss of 13 pounds, and
  • A loss of two inches around the lower waist (belly) – an area that was before intractable to his weight loss efforts.

After six months on TRE:

  • HbA1c was one percentage point lower – from 6.1% to 5.1% – she's longer pre-diabetic.

After eight months on TRE:

  • From the two month mark on, she became less restrictive about food choices, including the reintroduction of some refined carbs, without gaining weight. and was able to enjoy a full range of holiday foods.
  • She lost 20 pounds, or 12% of his starting body weight.
  • She lost four inches around the waistline.
Dr. Maherali's Overall TRE Assessment
  • It provides one clear rule he can follow — eat within a specific time window.
  • It worked for her friend who lost 28 pounds in four months, about 13% of body weight, using a fasting time of ~14 hours per night. This person did not overtly restrict food types (aside from eliminating 1-2 sodas per week), and did not feel deprived on this diet.
  • It improved her sleep quality, skin, and heart rate (lower pulse).
  • When we eat has profound implications for health, independent of food type or quantity, although quality macronutrients (protein, carbs, fats) will amplify better health outcomes.

What you now have is a map that will lead you to lower blood sugar, a particularly worthy goal should you need to reverse prediabetes, or even type 2 diabetes. In addition to TRE, there are also a few supplements that may help.

Reverse Prediabetes With Blood Sugar Supplements

If you want to potentially hypercharge the prediabetes reversing effects of Time Restricted Eating, consider four specific, scientifically-proven supplements. They are berberine, amla, mulberry leaf and cinnamon. Let's dig into each of them.

(1) Berberine

I came across berberine when researching effective blood sugar reducing supplements for my own use. I discovered that berberine is a compound derived from plants that lowers blood glucose levels by activating a protein called 5 AMP-activated protein kinase (AMPK).

AMPK is responsible for drawing glucose into cells and signaling the body to convert the fuel to energy. This lowers blood sugar levels without interacting with insulin. Berberine supplementation will not cause low blood sugar levels, also known as hypoglycemia, like excess insulin does.

The studies on berberine are pretty compelling; consider two studies done in 2008.

In one of the two studies, newly diagnosed Type-2 diabetics were divided into two groups: berberine and metformin users. Each group consumed 500 milligrams three times a day.

These were the results after three months:

  • Average fasting blood sugar in the berberine group dropped from 191 to 124 mg/dL.
  • Average post-prandial blood sugar dropped from 356 to 199 mg/dL.
  • Average hemoglobin A1c dropped from 9.5 percent to 7.5 percent.
  • Fasting triglycerides dropped from an average 99 to 78 mg/dL.
  • Insulin resistance dropped by 45 percent!

The researchers wrote:

Compared with metformin [discussed below], berberine exhibited an identical effect in the regulation of glucose metabolism, such as HbA1c, FBG [fasting blood glucose], PBG [blood sugar after eating], fasting insulin and postprandial insulin [insulin level after eating]. In the regulation of lipid metabolism, berberine activity is better than metformin. By week 13, triglycerides and total cholesterol in the berberine group had decreased and were significantly lower than in the metformin group (P<0.05) [5].

The other study compared two groups of diabetics over a three month period, one group taking 500 milligrams of berberine taken twice daily, and the other group taking a placebo twice daily.

These were the results of the berberine group:

  • Average hemoglobin A1c decreased from 7.5 to 6.6%.
  • Average triglycerides decreased from 221 to 141 mg/dL.
  • Average total cholesterol decreased from 205 to 168 mg/dL.
  • Average LDL-cholesterol ("bad" cholesterol) decreased from 125 to 97 mg/dL.

There were also positive but modest secondary outcomes [5]:

  • Body weight decreased by an average of five pounds in the berberine group; whereas the placebo group lost three pounds.
  • Systolic blood pressure decreased from an average of 124 to 117 and diastolic blood pressure decreased from an average of 81 to 77 in those treated with berberine, exceeding the fall from 126 to 123 systolic and from 83 to 80 diastolic in those who took the placebo.

I think supplementing with berberine is a no-brainer, as are the next three, as you'll soon see.

(2) Amla

I wrote about Amla in Eight Steps To Get More Sex and A Longer Life by Supercharging Your Blood. I'll summarize some of it here.

Also called "Indian Gooseberry", Amla just might be the biggest bang for your blood sugar lowering buck. In fact, the aforementioned Dr. Michael Greger of NutritionFacts.org says [6]:

Am I recommending people treat their diabetes with gooseberry powder? No, I recommend curing your diabetes… Why treat anything when you get at the root cause and reverse it in the first place.

Take a look at the graph below. It depicts the results of a study measuring the effect of Amla fruit on blood glucose and lipid (fat) profiles of Type-2 diabetic and non-diabetic participants [6] [7].

The blue line depicts the fasting blood sugar levels of the participants on diabetic medication, glyburide (sold as Diabeta or Micronase), and the red line shows those taking Amla.

At the beginning of the study, participants in each group (glyburide and Amla) have very high blood sugar levels, above 125 mg/dL, which by definition is a diabetic level. (100 to 125 is pre-diabetic; normal is below 100, but ideally should be below 90 — 85, says LEF.) [8]

Effect of Diabetic Medication and Amla on Fasting Blood Sugar

The Indian herb amla (Indian Gooseberry) reduces fasting blood sugar better than the diabetes drug Metformin.

Note that both the medication and Amla were very effective at quickly reducing fasting blood sugar to acceptable levels (under 100 mg/dL) within the first week, and then dropped it further over the subsequent two weeks, with Amla outperforming the drug.

(3) Mulberry Leaf

Mulberry leaf, also referred to as "white mulberry, is an herb. The powdered leaves are most commonly used for medicine, says WebMD, and are often used to help treat diabetes, high cholesterol and high blood sugar, among other health issues.

White mulberry leaves have various nutritional properties. There's a high content of polysaccharides, which increases insulin sensitivity and protects the pancreatic islets (groups of cells found within the pancreas that release hormones) from the effects of diabetes, thereby, improving glucose metabolism and protecting the body against damage by oxidative stress. In addition, they improve lipid metabolism, since their deregulation results in changes in insulin levels and glucose metabolism [9].

A review of various studies that examined the possible nutraceutical and medicinal potential of mulberry leaf for use in metabolic dysfunctions (such as high blood sugar in the prediabetic and diabete range) made the following conclusions:

  • Mulberry leaf exhibits a remarkable blood sugar ("glycemic") control and led to a reduction in fasting blood glucose in diabetic rats. Moreover, there was a reduction in triglycerides, total cholesterol, and LDL-c levels (the so-called "bad" cholesterol), and an increase in HDL-c levels ("good" cholesterol).

  • In a study using diabetic rats fed with a high-fat diet and treated with a mulberry leaf extract containing mannose, rhamnose, glucose, xylose, and arabinose, there was an improvement in glucose tolerance, a restoration of hepatic (liver) glycogen levels, an increase in insulin levels, and an improvement of hepatic (liver) oxidative stress.

Nearly all studies that examined the effects of mulberry leaf on blood sugar have been done on rats and mice, but the above mentioned review of mulberry leaf studies included one that looked at women with impaired glucose tolerance. They received 75 grams of cooked rice coated with mulberry leaf extract, which resulted in reduced postprandial blood glucose levels when compared to the group receiving plain rice. "Postprandial" refers to a period after a meal, which in this case was one to two hours. Apparently, mulberry leaf may work to lower blood sugar in humans, too.

(4) Cinnamon

While berberine, amla and mulberry leaf may have been new to you, everyone is familiar with cinnamon. Perhaps what you don't know, however, is that this spice has many medicinal properties.

As Healthline reports, cinnamon is:

    • Loaded with antioxidants,
    • Has anti-inflammatory properties,
    • May cut the risk of heart disease,
    • Helps fight bacterial and fungal infections,
    • Can improve sensitivity to insulin, and
    • Lowers blood sugar levels.

      Given that the topic on point is how you can reverse prediabetes, let's focus on the last two in the above list, insulin sensitivity and blood sugar levels.

      Insulin is an important hormone that regulates metabolism and energy use, and is essential for transporting blood sugar from your bloodstream to your cells. People with persistent high blood sugar are typically resistant to the effects of insulin. Such "insulin resistance" is a notable attribute of metabolic syndrome and type 2 diabetes.

      Cinnamon can dramatically reduce insulin resistance, and thereby help this important hormone to increase insulin sensitivity and lower blood sugar [10] [11].

      Cinnamon helps lower blood sugar through two mechanisms:

      • First, it decreases the amount of glucose that enters your bloodstream after a meal by interfering with numerous digestive enzymes, which slows the breakdown of carbohydrates in your digestive tract [12] [13].
      • Second, a compound in cinnamon acts on cells by mimicking insulin, a process slower than insulin, but one that improves glucose uptake by your cells, nonetheless [14] [15].

      Numerous human studies have confirmed the anti-diabetic effects of cinnamon, showing that it can lower fasting blood sugar levels by 10–29% [16] [17]. Seems to me to be a no-brainier that you should use this spice liberally.

      Your Takeaway

      You can improve many biomarkers for health, and potentially reverse diabetes, by doing just four things:

      1. Reducing the time span within which you eat to less than 12 hours; and
      2. Stop all eating and drinking (except water) by 7:00 PM or earlier, which will best align you with your circadian rhythms.
      3. Give yourself a relief valve; meaning, when you feel you need a break, return to your comfort zone rather than abandon the time restricted eating (TRE) protocol entirely.
      4. Try taking one or more of the blood sugar reducing supplements profiled above.

      Taking supplements is simple, and easy to do. TRE is simple, but hard to do.

      If you want to reverse prediabetes, I strongly recommend that you give TRE a whirl, but approach it slowly. Try reducing your feeding window by only 1/2 hour each week, and pushing back the last hour you eat at night by 1/2 hour each week as well.

      And know that there's no way to get around feeling hungry at first. You'll have to become accustomed to that feeling without panicking. Try drinking purified water. If that doesn't help, add some cold pressed organic apple cider vinegar to the water or herbal tea. Eventually, exclude it so that you're only drinking water.

      One last word on the matter is to recruit a friend, or better yet, whomever you live and eat with. It's very helpful to have someone to lean on when you seek to change something so ingrained as when you eat, because change is hard.


      1. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(12)60283-9/fulltext
      2. https://www.lifeextension.com/Magazine/2012/2/Suppress-Deadly-After-Meal-Blood-Sugar-Surges/Page-01
      3. https://onlinelibrary.wiley.com/doi/epdf/10.1038/oby.2009.264
      4. https://www.cell.com/cell-metabolism/pdf/S1550-4131(12)00189-1.pdf
      5. https://web.archive.org/web/20170918011711/http://www.tahomaclinicblog.com/berberine-diabetes/
      6. http://nutritionfacts.org/video/amla-versus-diabetes/
      7. https://www.ncbi.nlm.nih.gov/pubmed/21495900
      8. http://nutritionfacts.org/video/amla-versus-diabetes/
      9. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6358891/
      10. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2901047/
      11. https://www.ncbi.nlm.nih.gov/pubmed/18234131
      12. https://www.ncbi.nlm.nih.gov/pubmed/21538147
      13. https://www.ncbi.nlm.nih.gov/pubmed/21711570
      14. https://www.ncbi.nlm.nih.gov/pubmed/11506060
      15. https://www.ncbi.nlm.nih.gov/pubmed/9762007
      16. https://www.ncbi.nlm.nih.gov/pubmed/19930003
      17. https://www.ncbi.nlm.nih.gov/pubmed/17381386

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