Like glucose, insulin is essential to life. This hormone acts like a key, unlocking cells so glucose — their main source of fuel — can enter.

Insulin is effectively an energy-storage hormone. Because glucose fuels cellular energy, the body is wired to detect sweetness. When sensors in the tongue taste something sweet, they signal the pancreas to release insulin. That insulin spritz relocates sugar from the blood to the cells in anticipation of incoming nutrients, including more sugar.

When sensors in the tongue taste something sweet, they signal the pancreas to release insulin. That insulin spritz relocates sugar from the blood to the cells in anticipation of incoming nutrients, including more sugar.

Called anticipatory insulin response, this process is critical for our health, says Paul Breslin, PhD, a nutritional sciences professor at Rutgers University and researcher at Monell Chemical Senses Center. He likens it to how an airport prepares for a plane’s arrival.

“Imagine what air travel would be like if every time a plane landed at the airport, it was a big surprise. It would be total chaos,” he says. “The same is true for human physiology. If you wait for nutrients to show up in your blood, it’s too late — you would have sky-high blood sugar that requires a huge amount of insulin to move out of the blood.”

The body keeps blood-sugar levels within a narrow range, says integrative psychiatrist Henry Emmons, MD, author of The Chemistry of Calm. “If blood sugar is consistently elevated, even by a slight amount, it can create long-term problems.”

Consistently elevated blood sugar can weaken the ability of cells to respond to insulin in the bloodstream. This is known as insulin resistance, a hallmark of most metabolic disorders. If cell doors stay closed when insulin knocks, glucose builds up in the bloodstream. This is what spurs type 2 diabetes: The body loses its ability to regulate blood-sugar levels without supplemental insulin. (Here are “6 Strategies to Manage High Blood Sugar.”)

In recent years, diabetes — both types 1 and 2 — has become a runaway epidemic, says nephrologist Jason Fung, MD, author of The Diabetes Code. “Since type 2 diabetes constituted about 90 to 95 percent of all diabetes, this was a pretty serious problem,” Fung says. But the American Diabetes Association (ADA) no longer considers type 2 diabetes as an inevitably chronic and progressive disease. Indeed, type 2 diabetes can be reversed, he explains. We spoke to him about the disease and his treatment approach.

Experience Life | We used to fear that type 2 diabetes was a life sentence. But new evidence says this is not the case?

Jason Fung | Type 2 diabetes is largely a dietary and lifestyle disease, and reversing it does not require drugs, but a change in the diet and lifestyle. If people lose weight, their diabetes would either get much better or go away. Many, many scientific studies showed this exact same thing.

I published The Diabetes Code in 2018, which said in plain English that the idea that type 2 diabetes is irreversible is a lie and a particularly dangerous one, because it would lead people to give up hope for remission. Several years after that (2021), the ADA published criteria for remission, tacitly admitting that this indeed was reversible disease.

EL | Do conventional treatments that rely on insulin or other blood-glucose-lowering drugs help, or can they exacerbate the problem, leading to other concerns, such as weight gain and even heart disease?

JF | There are many types of drug treatment for lowering blood glucose — some good, some bad, and some downright ugly. Dietary treatment is always best because that is the root problem. However, drugs certainly have their place in treatment.

We know that obesity and type 2 diabetes are closely related. The newest medications — GLP1 [agonists] and SGLT2 inhibitors — lower blood glucose but also tend to cause weight loss, so they’re good. Metformin and other DPP4 inhibitors are usually weight neutral, so they’re also neutral.

The older medications, which include insulin and sulphonylureas, are downright ugly because they cause weight gain.

Consider this scenario, which is all too common, even now: An overweight patient was diagnosed with type 2 diabetes and eventually put on insulin, which was considered first-line treatment only a few years ago. This insulin causes them to gain weight — some 20 or 30 pounds. As they gained weight, their type 2 diabetes got worse. This meant they needed more insulin. Which caused more weight gain. Which made them need more insulin. And so on.

This patient’s blood glucose was getting better, but their type 2 diabetes was getting worse. Does this seem to be a good treatment? It’s rather like treating alcohol withdrawal with more alcohol. Yes, the shakes get better, but the alcoholism, the actual disease, was getting worse.

EL | What is your recommendation for treating type 2 diabetes effectively?

JF | Dietary treatment is the most important since this is a dietary disease. The ADA says reducing carbohydrates can aid blood-sugar management. In published, real-world studies you can put about 50 percent of type 2 diabetics into remission with such a diet.

It’s not hard to understand: Carbohydrates are sugar molecules. If you eat carbs, which your body breaks down into glucose, your blood glucose (blood sugar) goes up. If you eat proteins and fats (you are eating amino acids and fatty acids), then you are not eating sugar and your blood sugar does not go up. That is, some foods — especially carbs — raise blood glucose and other foods don’t raise blood glucose. Obviously, it makes sense to eat more foods that don’t raise blood glucose and less of those that do. In sum, reduce carbohydrates.

This effect is clear in a food’s glycemic index (GI), which measures how much blood sugar goes up with certain foods. Some foods raise blood sugar a lot; others not at all. It only applies to carbohydrate-containing foods because the glycemic index of an egg is zero. GI for beef is zero, etc.

The other significant way to treat type 2 diabetes is intermittent fasting. Again, not hard to understand: If you don’t eat, your body will start burning the excess glucose in your body. If your blood glucose goes down, you don’t need medications to do it. Eventually, you can stop all medications, which means remission.

EL | Is it possible to reverse type 2 diabetes even if you’ve had it for a number of years, or is this mostly if you catch it in an early stage?

JF | It is reversible in most cases but not all. It depends upon how long you’ve had diabetes and how severe it is. It’s best to catch it early, but I’ve seen people reverse their disease even with a 20-year history of the disease.

EL | What do you recommend for type 2 diabetes prevention in the first place?

JF | I recommend the same things: reduce refined carbohydrates, practice intermittent fasting.

Fasting is a part of everyday life. If you don’t eat after dinner (say, 7 p.m.) until breakfast the next day (say, 8 a.m.), that is a 13-hour period of fasting that you should have every single day without thinking about it. It’s normal. The very word “breakfast” suggests that you must fast, and then break your fast, meaning it’s just a part of a normal cycle — there is a time to eat (feed) and a time to not eat (fast). If you keep those cycles balanced, you should be OK.

These tips can be used safely alongside prescription drugs that control blood sugar (such as Metformin and supplemental insulin) and may help reduce or eliminate the need for prescriptions over time.

1. Eat Balanced Meals

The simplest way to manage blood sugar is to consume less glucose. “If you eat a lot of glucose — and that’s not just sugary foods but starchy carbohydrates like bread, rice, and potatoes — then your blood glucose goes up,” says nephrologist Jason Fung, MD, author of The Diabetes Code.

The glycemic index (GI) ranks carbohydrates based on their impact on blood-sugar levels. Foods with a low GI tend to be absorbed more slowly, causing a more gradual, modest rise in glucose.

Still, the GI can only serve as a general guide because responses to glucose are highly individual. Genetics, the microbiome, body composition, and portion size all affect that response, which is why two people can have completely different reactions to the same food. (This is why a continuous glucose monitor can come in handy; more on that in a bit.)

Restrictive eating can lead to problems of its own, however, so rather than focusing exclusively on cutting down on carbohydrates, ­Jill Weisenberger, MS, RDN, author of Prediabetes: A Complete Guide, advocates for taking a broader view of a healthy diet. “Too often, people focus only on calories for weight, carbs for blood glucose, sodium for blood pressure, or fat for ­cholesterol,” she notes. “This myopic view of health and diet rarely leads to good outcomes.”

Make sure every meal contains combinations of different nutrients. This can naturally curb an over-emphasis on carbs.

Instead, emphasize variety. Make sure every meal contains combinations of different nutrients. This can naturally curb an over-emphasis on carbs. “Having a balanced meal tends to lead to better blood-sugar control than a carbohydrate-heavy meal without some protein or fiber,” Weisenberger says.

Protein is typically more filling than carbohydrates, so it can help reduce over­eating and snacking. It also slows the absorption of carbohydrates, moderating their effect on blood sugar. Healthy fats (think nuts, seeds, avocados, and olive oil) produce a similar moderating effect on carbohydrates.

Fiber — both soluble and insoluble — is crucial here too. “Having a couple of foods at every meal with different types of fiber is going to be beneficial,” Weisenberger explains. “Some fibers slow down the release of glucose into the blood, and some are food for the good bacteria that produce helpful compounds that reduce insulin resistance.” (Wondering how much protein you actually need?  Learn more about this macronutrient and how to get it from healthy sources.)

Finally, try eating your carbohydrates after some fiber, fat, and protein. “When you go to a restaurant, they start by bringing you bread, which is the worst thing to eat first,” says Elizabeth Boham, MD, MS, RD, a functional-­medicine physician in Lenox, Mass. “Instead, start with salad with some olive oil. Starting with fiber, protein, and fat really helps with balancing blood sugar.”

2. Move More

When we exercise, we increase our body’s sensitivity to insulin, which decreases insulin resistance. And anything that decreases insulin resistance is going to help manage blood glucose.

Both cardio and strength training offer benefits here — and a combination of the two is best. “The increased insulin sensitivity following exercise could last for a couple of hours or a couple of days, depending on the duration and intensity of the exercise,” Weisenberger says.

Boham recommends two strength-training sessions and at least 150 minutes of cardiovascular exercise per week — and not all the cardio needs to be intense. “Going for a walk after you eat dinner is a wonderful activity that can help improve blood sugar after a meal,” she says.

The very act of exercising helps remove glucose from the blood, even if you’re insulin resistant.

Strength training helps build lean muscle mass, which is crucial for absorbing glucose. “The preferred place for blood sugar to go after eating is to the muscle, but if we don’t have a big muscle, we don’t have a big repository for that sugar to enter,” Weisenberger explains. (For more, see “Why Strength Training Is Essential.”)

She compares muscles to small and large buckets in a rainstorm — the big ones are going to hold a lot more rain. “That’s why we don’t want to lose muscle mass as we age; we want to build as much muscle as we possibly can.”

The very act of exercising helps remove glucose from the blood, even if you’re insulin resistant. “If you’re actively using your muscles, they don’t need those messages from insulin in order to take up sugar,” Weisenberger says.

Though longer bouts of exercise are most effective, simply moving around throughout the day also counts. Research shows that breaking up long periods of inactivity helps improve insulin sensitivity. The American Diabetes Association recommends three minutes of movement for every 30 minutes of extended sitting.

“That could just be walking to the bathroom, moving the laundry from the washer to the dryer, or getting up and doing some squats and stretches,” Weisenberger notes.

3. Try Time-Restricted Eating

Time-restricted eating (TRE) is a moderate form of intermittent fasting in which you eat only during a specific window of time each day. Usually that window is between four and 10 hours long. Studies indicate that TRE can lead to a reduction in fasting insulin levels, improved insulin sensitivity, and better glucose tolerance.

“If the underlying problem in prediabetes is too much glucose, you can either put less glucose into the system or let your body burn off the excess, which is what intermittent fasting does,” Fung says. “It’s the most powerful natural therapy for type 2 diabetes.”

Fung compares a body with too much glucose to an overflowing sink. “The strategy we have right now is that when the sink overflows, we get mops,” he says, referring to the medications used to manage type 2 diabetes. “But the best strategy is to turn off the tap and let the water drain out. Let your body burn off the glucose.”

During fasting, the body uses stored glucose, which is primarily glycogen from the liver, to meet its energy needs. As glycogen stores diminish, the body starts to burn fat for energy. This may help improve insulin sensitivity.

If you decide to try TRE, keep in mind that the body becomes more insulin resistant as the day goes on. “If you eat the same meal at noon or at 8 p.m., you’ll produce a higher amount of insulin after the later meal,” Boham notes. “[Eating] earlier is better when it comes to insulin resistance and prediabetes.” (To learn if you’re a good candidate for TRE, see “Everything You Need to Know About Intermittent Fasting.”)

4. Consider a ­Continuous Glucose Monitor

If you’re curious about your individual response to carbohydrates, a continuous glucose monitor (CGM) can be a useful tool. This device measures blood-sugar levels in real time with a sensor placed under the skin. A CGM may be prescribed by a doctor if you have type 1 or type 2 diabetes, but you can also find over-the-counter brands.

“CGMs give you information that you couldn’t get otherwise,” Fung says. “We know what the average response to any given food is, but we don’t know what your personal response is going to be. The CGM gives us personalized information about what foods are doing to us.”

A CGM may also offer insight into how sleep, stress, and meal timing are affecting your blood sugar, Boham adds. Still, she cautions that a CGM is best used for a short time, to avoid focusing too much on one kind of metric, and with the support of a pro­vider who can help you interpret the information.

(Considering a CGM? Learn if one may be right for you.)

5. Reduce Inflammation

“Prediabetes is an inflammatory disorder,” Boham says, so training your focus on reducing inflammation can yield big benefits.

The simplest way to cool inflammation is by eating fewer inflammatory foods, especially hyperprocessed fare and known allergens like dairy and gluten. Increasing inflammation-fighting compounds from fresh, whole plant foods also helps. (Our bodies need inflammation to fight off infection, but too much of it for too long can spur a wide range of illnesses. Learning to manage it effectively is key. See “How Chronic Inflammation Affects Your Health” for a deep dive on this subject.)

“There’s been great research on phytonutrients and how they can help decrease inflammation after a meal,” Boham explains. “So, in addition to protein, fats, and fiber at each meal, think about including colorful plant foods. Just adding more spices to your meals can be really helpful.”

Regular relaxation also helps calm the system. “When we’re in a state of stress, our blood sugar goes up,” she says. “It makes sense. If you’re running from a tiger, the body wants more glucose in the blood so it can use it to run away.”

The reverse is true as well. “If we activate the parasympathetic, calming nervous system, we can actually bring down our blood sugar.”

Weisenberger adds that poor sleep is a type of physical stress on the body. “One night of poor sleep will increase insulin resistance even in healthy people. But if somebody habitually gets bad sleep, then we can see a big difference in insulin sensitivity.”

6. Experiment With Cold Therapy

A small body of research suggests that cold therapy — such as cryo­therapy, ­polar plunges, ice baths, and cold showers — can lower fasting glucose and insulin levels and improve insulin sensitivity.

It may confer some of these benefits by creating what’s known as brown fat. “When we think of fat, we usually think of white fat, which stores calories. But there’s also brown fat,” Fung explains.

Brown fat stores energy in a smaller space than white fat; it also generates body heat and burns caloric energy.

Regular cold exposure helps generate more brown fat. “If it’s burning energy, that’s going to be useful in the treatment of prediabetes because it’s using up glucose,” Fung says, adding that more research is needed.

As always, the most sustainable way to manage your blood glucose is a personalized, holistic approach that suits your individual needs. If your A1C is running high, it’s worth the time to learn what works for you. Building supportive diet and lifestyle habits can mean the difference between managing a progressive metabolic disease or turning the tide for good.

Various drugs have long been used to help manage diabetes, including the commonly prescribed Metformin. In 2017, the U.S. Food and Drug Administration approved a semaglutide drug — part of a class of medications known as glucagon-like peptide 1 receptor agonists — with the brand name Ozempic for the treatment of type 2 diabetes.

Since then, semaglutide has also been approved for weight management under the brand name Wegovy. These injectable medications lower blood-sugar levels, increase feelings of fullness, and delay the emptying of the stomach after eating.

“The major reason these drugs work is that they cause you to lose your appetite,” explains nephrologist Jason Fung, MD. “But if you don’t pair that with proper dietary habits, then it’s just a temporary fix because as soon as you stop taking the drug, all the changes reverse.”

“The major reason these drugs work is that they cause you to lose your appetite,” explains nephrologist Jason Fung, MD. “But if you don’t pair that with proper dietary habits, then it’s just a temporary fix because as soon as you stop taking the drug, all the changes reverse.”

A 2023 analysis of pharmacy claims found that two-thirds of people who were prescribed weight-loss drugs like Wegovy stopped taking them within one year. Cost may be a factor, especially for people paying out of pocket. Side effects are another. These can include nausea, vomiting, diarrhea, and, more rarely, stomach paralysis, bowel obstruction, and pancreatitis.

Fung notes that curbing your appetite may be a blessing in the short term, but it loses its appeal. “These drugs take away hunger, but they also take away the pleasure of eating. If you take that away for six months, people are happy because they’re losing weight and getting healthier. But take that enjoyment away for two, three years, and it leads to poor compliance. And when you stop taking it, the problems multiply.”

“The biggest concern with these medications is that we’re seeing too much loss of lean muscle mass,” explains functional-medicine physician Elizabeth Boham, MD, MS, RD. “Whenever you lose lean muscle mass, your metabolism decreases.” Studies show that lost muscle mass also contributes to frailty in older adults.

Furthermore, the weight people regain after stopping the medication generally comes back as fat instead of muscle.

A personalized risk–benefit analysis may come out in favor of semaglutide for some people facing certain or extreme health challenges. “If it helps someone not have gastric bypass surgery, there may be a net benefit,” Boham says. Regardless, anyone who opts to take semaglutide will benefit from working with a personal trainer to minimize loss of lean muscle mass.

Our bodies are constantly working to keep our blood-sugar levels in a healthy range. This helps ensure our cells receive a steady supply of energy. Yet sometimes the complex interplay of hormones and other physiological processes — as well as the quantity, quality, and timing of the food we eat — destabilizes these levels.

If blood glucose falls too low, we may feel dizzy, fatigued, and shaky, or we may even pass out. High blood ­sugar — a hallmark of diabetes — can lead to extreme thirst, excessive urination, blurred vision, nausea, and headaches. If high blood sugar becomes chronic, it can result in nerve and organ damage, heart disease, and stroke.

Routine lab work during a doctor’s visit often includes a fasting glucose test; this measures how much glucose remains in the blood after an eight-hour fast. A level less than 100 milligrams per deciliter is considered normal. A higher reading might prompt your doctor to order an A1C test, which reveals the body’s blood-glucose levels over time.

Here’s how the test works: Glucose binds to hemoglobin, a protein in red blood cells that carries oxygen throughout the body, in a process called glycation. The A1C test measures the percentage of hemoglobin that is glycated.

Because red blood cells live for about three months, the test reflects the average blood-glucose levels over that period. “The higher your blood sugar is, and the longer it is high, the higher your A1C will be,” explains Jill Weisenberger, MS, RDN, author of Prediabetes: A Complete Guide.

An A1C level below 5.7 percent is considered normal. A level of 5.7 to 6.4 percent is classified as prediabetes, and a level of 6.5 percent or higher indicates diabetes.

A1C Average Glucose Levels	Normal	Prediabetes	Diabetes
AIC LEVEL (%) →	BELOW 5.7	5.7–6.4	6.5 OR ABOVE