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If you think all is well with your blood-sugar levels just because you don’t have diabetes, you could be mistaken.

One in three U.S. adults have impaired blood-sugar control — and only 8 percent are aware they have an issue. And for the 10 percent of U.S. adults and kids with full-blown diabetes, a whopping one in five don’t know they have it.

Considering diabetes can lead to heart attack, stroke, kidney failure, nerve issues, limb amputation, and blindness, these numbers are understandably alarming. Lesser-known consequences of poor blood-sugar regulation can include cravings, chronic inflammation, trouble losing fat, erectile dysfunction, increased Alzheimer’s disease risk, and even faster aging. 

From an economic standpoint, diabetes costs, on average, almost $10,000 more per year in medical expenses than not having diabetes.

Addressing brewing blood-sugar issues and preventing diabetes is a critical component of anyone’s health priority list. It’s rampant and insidious, but, in most cases, controllable. This healthy blood-sugar guide reviews what you need to know.

Blood Sugar Basics

The body wants to maintain a relatively narrow range of sugar — or glucose — in the bloodstream. Significant medical problems, up to coma and death, can arise when sugar concentrations swing too far outside of these ranges. Luckily, for most of us, there is a complex web of systems in place to prevent those fluctuations from being lethal.

However, even minor swings outside of these ranges can have negative health consequences. Here’s an overview of how blood sugar works:

  • Sugar in the blood comes either from the foods we eat or is produced by the liver.
  • When blood sugar rises, our cells can use it for energy (when we’re active), and the pancreas releases a hormone called insulin. The insulin release lowers blood sugar by either putting it into storage as glycogen (in the liver or muscles) or into fat tissue. Our glycogen stores are limited, but unfortunately, our fat storage is not.
  • Carbohydrates, especially those that are refined and low in fiber (such as sugary foods and most bread, cereals, and pasta) can cause a rapid spike in blood sugar, much more so than proteins, fats, and high-fiber foods.
  • If blood sugar goes too low or if too much time passes between meals, a hormone called glucagon breaks down the stored form of carbohydrate in the liver to boost blood sugar until the next meal.

This spike in blood sugar from the liver — called gluconeogenesis, or formation of new glucose — can also happen in response to growth hormone, epinephrine (adrenaline), and cortisol, our body’s stress hormone.

Common Issues With Blood Sugar

Think of health and disease on a spectrum: If optimal blood-sugar control is on one side, a diabetes diagnosis (especially type 2 diabetes) is on the other. It can take months, years, or even decades to move along this path. With every step of the way, health risks and complications mount.

There are a few primary categories of blood-sugar issues:


This is dangerously low blood sugar. It can happen when the body produces too much insulin (such as after a meal very high in sugar or carbohydrate), after drinking alcohol, after going too long without eating, or with certain medications and conditions. In those with diabetes, it can occur when too much medication and/or insulin is given.


This is when blood sugar is higher than normal, but not high enough to be diagnosed as type 2 diabetes. There’s a good chance of eventually getting diagnosed if lifestyle and nutrition interventions are not implemented.

Type 2 diabetes

This is the more common form of diabetes and is most often linked to controllable lifestyle factors, although genetics can also increase your risk.

In this form of diabetes, the pancreas produces insulin (which lowers blood sugar), but the body does not use it properly, causing levels of blood sugar to rise. This poor response is referred to as insulin resistance. Progressively worsening insulin resistance leads to a diabetes diagnosis.

Type 2 diabetes used to be called “adult-onset” diabetes, but it is now impacting children and younger adults at alarming rates. Oral medications — or even extra insulin — might be needed to control it.

Gestational diabetes

This is when diabetes is identified for the first time during pregnancy. It can cause complications for both the mother and the baby. While there are various proposed causes, such as hormone changes that happen during pregnancy, it sometimes can result from blood-sugar issues that existed before pregnancy that are first identified from screenings done during pregnancy.

Often, blood sugars go back to normal after delivery, but the risk of developing type 2 diabetes in the next decade is 10-fold higher for moms who had gestational diabetes during pregnancy.

Type 1 diabetes

This condition is rare in comparison to type 2 diabetes. It’s often — but not always — triggered in childhood, and so sometimes is referred to as “juvenile diabetes. It’s considered an autoimmune condition and causes the pancreas to secrete little to no insulin. Therefore, taking insulin daily is required to survive.

Each of these blood-sugar issues can contribute to chronic inflammation and come with a host of associated health risks.

How Do I Know If I Have Blood Sugar Issues?

Subjective symptoms sometimes, but not always, can provide clues that blood sugars are unstable. When blood sugar first starts going wonky, you may notice:

  • Significant energy swings after eating, including either a noticeable boost in energy or fatigue after meals
  • Cravings for sugar, starch, and carbohydrates
  • Trouble staying asleep
  • Feeling “hangry,” including irritability, shakiness, or headaches between meals
  • Extreme thirst, excess urination, and blurred vision in more severe cases

Objectively, lab testing is the gold standard in identifying issues:

  • Blood-sugar trends: General medical cutoffs for blood sugar are 70 mg/dL on the low end and less than 140 mg/dL an hour or two after eating. Fasting blood sugar levels are considered normal when under 100 mg/dL, but evidence suggests that optimal fasting blood-sugar control is actually closer to 82 to 88 mg/dL.
  • Insulin (or the surrogate marker of insulin, C-peptide): This hormone is released when blood sugar increases. Conventional reference ranges for insulin can surge up to 25 mIU/L and still be considered normal, however many functional health practitioners target values of less than 10 mIU/L. 
  • Hemoglobin A1C: This blood test helps estimate your blood-sugar control over the previous three months. Measured as a percentage, a solid target is less maintaining a level that is than 5.3 percent, with most conventional ranges considering any value below 5.7 percent as normal.
  • Glucose tolerance test: This involves drinking a standardized amount of glucose solution and measuring the blood-sugar response one to two hours later. It’s often used in screening for gestational diabetes during pregnancy.
  • Triglycerides: Although this is a type of fat in the blood, high triglycerides can suggest a caloric surplus, particularly from high-carbohydrate foods (which raise blood sugar). Triglycerides are often high in uncontrolled type 2 diabetes. While anything under 150 mg/dL is considered medically normal, optimal levels might be less than 100 mg/dL.

Keep in mind that for the above tests, the medical reference range may not represent the optimal range of the health spectrum. If lab markers start to drift toward either end of the diagnostic range, it’s a signal that it’s time to try to bring things under control.

How Do I Control My Blood Sugar?

Manage Your Weight

Of those with diabetes, 89 percent are estimated to be overweight or obese. Studies show that a 15 percent weight loss can put half of those with diabetes into remission.

The main difference in those who recover versus those who don’t is the health of beta-cells, the insulin-producing cells of the pancreas. The sooner healthy habits are put into place, the more likely it is that the health of these cells can be preserved. This means that intervening early is crucial.

Weight control involves managing the complexity of calorie balance, along with addressing sleep, exercise and activity levels, stress, and underlying health issues and hormone balance.

Caveat: Remember, you can’t judge a book by its cover. If 89 percent of those with diabetes are overweight, that means 11 percent are normal weight, with a BMI of less than 25.

Train Regularly and Lift Heavy

Good news: If you worked out today, your cells are likely more responsive to insulin (which lowers blood sugar) for the 16 hours following your sweat session. When thinking long term, maintaining and gaining lean muscle mass might serve as an antidote to high blood sugar. Physical activity is a non-negotiable.

As we get older, a decline in muscle mass can increase the risk of developing type 2 diabetes. Clearance, or lowering, of blood sugar is better in strength-trained muscles. One of the reasons this happens is due to a transporter called GLUT4.

Think of GLUT4 as a doorway that glucose can use to get out of the bloodstream and into muscle cells, even if the cells are insulin resistant. Muscle contractions — such as those when we lift weights and resistance train — increase the concentration of these doorways of our cells so that blood sugar can lower more effectively.

In those with diabetes, resistance training of all intensities can help lower blood sugar. As intensity increases, hemoglobin A1C (the three-month marker of average blood sugar) can start to decrease as well. This is a good thing.

The positive impact of training on blood sugar can happen remarkably quickly. In fact, a mouse study showed that insulin sensitivity and blood-sugar stability improved in as little as 15 days, even before changes in weight occurred. While findings of mouse studies can’t automatically be applied to humans, the results are encouraging — and can help provide the motivation needed to get started with an exercise program.  

Prioritize Protein

When protein is included at meals, especially those containing starches or carbohydrates, it can help slow the rise of blood sugar.

On top of that, it’s been shown that those with higher protein intake (when combined with regular exercise) gain lean, strong muscle tissue and lose body fat more effectively than those with lower protein intakes, even if they exercise.

This is likely due to muscle protein synthesis, or gain of lean body mass (and therefore strength). If you’ve heard confusing messages about protein intake in the media (especially animal protein), check out this article about the benefits of a high protein diet.

From a weight management standpoint, including protein can help you lose fat instead of muscle. And since 25 to 30 percent of the calories in protein are burned in digestion (compared to 2 to 3 percent for fat and 6 to 8 percent for carbohydrates), it can put you in a slightly larger calorie deficit without having to sacrifice how much food you’re eating.

Aiming for one to two palm-size portions of high-quality protein per meal, such as poultry, fish, eggs, or dairy (if tolerated), is a good starting point for most. It’s ideal if your protein intake is spread out throughout the day as well.

Focus on Fiber Density

An eight-week study of people without diabetes showed that with calories equal, a higher fiber diet could support weight loss and insulin sensitivity.

A trip down the aisles at the grocery store would make anyone think that cereal is the best source of fiber to include. However, you might be better off focusing on the amount of fiber you’re getting in comparison to the total calories and carbohydrates you’re eating.

Getting the recommended minimum of 25 grams of daily fiber for women and 38 grams for men can be done by eating highly marketable grain products and processed foods — or it can be done primarily through non-starchy vegetables, some high-fiber fruit (like berries), and portions of nuts and seeds.

In the former, carbohydrate intake can skyrocket and surge blood sugar and insulin levels. In the latter, blood sugar is likely going to remain more even and calories will be easier to control, whether or not you’re counting them.

For example, two cups of broccoli provides about five grams of fiber, just under 60 calories, and 12 grams of carbohydrate. To get the same amount of fiber from a popular breakfast cereal touted for its “heart-healthy whole grains,” you would have to consume 167 calories and 33 grams of carbohydrate.

Moderate Your Carbohydrate and Calorie Intake

Even without a significant drop in caloric intake, a short-term, lower-carbohydrate approach may support insulin and blood-sugar control in those with prediabetes. There may also be favorable effects on triglycerides and HDL (or “good” cholesterol).

That’s not to say that going lower carbohydrate is a long-term miracle cure or that we should be fearful of mindfully including carbohydrates in our plan. But since all carbohydrates (except fiber) break down into sugar, it’s no surprise that moderating your carbohydrate intake is a good idea.

Generally, starchy carbohydrates (such as lentils, sweet potatoes, or oats) are better tolerated as activity levels and muscle mass increase. Try to time them around exercise and be sure that the portions you’re eating are not infringing on your intake of blood-sugar stabilizing protein and non-starchy veggies.

In other words, prioritize your protein and vegetables. Add in any carbohydrates as needed, choosing nutrient-dense, high fiber options as often as possible.

Boost Omega-3s

Omega-3 fatty acids help support a healthy inflammatory response, which can be threatened when blood sugars are out of whack.

There are three types of omega-3 fatty acids: alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). The ALA form is found mostly in plants and must be converted to EPA and DHA to be usable in the body, but this only happens to a small degree.

A meta-analysis looking at 20 different studies including over 1,000 participants showed that EPA and DHA had a significant positive impact on triglyceride levels and some additional benefit to hemoglobin A1C levels. Similar results were found in studies of both children and those with non-alcoholic fatty liver disease.

In another meta-analysis that did not look at triglycerides, no effect was seen on blood sugar — but it was found that supplementation with ALA (the plant-based form that needs to be converted) might actually increase insulin.

When optimizing omega-3 fatty acid status, focus on the EPA and DHA forms found in fatty fish and fish oils, and consider looking into the health benefits of fish oil supplements.

Optimize Vitamin D and Magnesium

Magnesium and vitamin D are the most common mineral and vitamin deficiencies, respectively. And both are intimately involved in blood-sugar control.

Magnesium can be found in greens, beans, and cocoa — but most people are not getting enough. When low, insulin sensitivity is reduced. Many people benefit from an additional magnesium supplement — even if some magnesium is already included in their high-quality multivitamin — because the mineral takes up so much physical space.

Getting enough vitamin D can also support improvements in insulin resistance. One study showed that just 1,332 IU of vitamin D daily for one month could decrease insulin resistance by 21 percent — and that is in those who started with an average vitamin D level of 35.1 nmol/L (or 14 ng/mL).

For context, the Vitamin D Council recommends a target blood level of 100 to 250 nmol/L (or 40-100 ng/mL). If you don’t know your levels, be sure to get tested and dose it appropriately, as some people may require 5,000 to 10,000 IU daily of vitamin D3 (combined with vitamin K2) to reach optimal ranges. 

It’s no surprise that we include both vitamin D and magnesium in the Foundational Five supplements we recommend as a starting point for everyone.

Get Enough Sleep

Studies have shown that those who sleep less than six hours are more than four times more likely to have high fasting blood sugar. Sleep disorders, such as sleep apnea, can raise both blood sugar and hemoglobin A1C.

Even partial sleep deprivation (or less than seven to eight hours nightly) can change appetite-regulating hormones, causing more feelings of hunger and less of an ability to feel full.

Feeling hungrier and insatiable, especially with higher glucose levels in the blood, is a recipe for trouble. The importance and benefits of adequate sleep are limitless, so do whatever you can to protect and optimize your sleep schedule.

Control Your Stress

Stress management and supporting the adrenals are both non-negotiable for long-term health.

Cortisol, often referred to as the body’s stress hormone (although it’s one of many), is in a class of compounds called glucocorticoids. These compounds are important for the regulation of inflammation, but they also directly increase blood sugar — even if you’re exercising or eating a lower carbohydrate diet.

I’ve personally worked with clients who have had stubborn blood-sugar issues despite being dialed in with their body composition, nutrition plan, exercise programming, sleep schedule, and supplement regimen. While they saw some improvements in blood-sugar control with each piece that was addressed, their levels were not optimized until a purposeful stress management protocol was put in place.

Stress management can come in various forms: yoga, Pilates, mediation, prayer, alone time, signing off social media, gardening, a walk in nature, Epsom salt baths. Find the strategy that works for you — and remember that effective stress management is in fact a productive use of time.


We can’t always change our circumstances, but we can, however, address our perception and strategies to cope with them.

Other Potential Blood-Sugar Support 

As always, be sure to work with your medical team before implementing a new supplement plan, including the ones outlined here.


Studies have shown mixed results on the impact of cinnamon with blood sugar. It appears that it might have the potential to reduce blood-sugar spikes after meals, especially in those with poorly controlled diabetes.

Takeaway? It might be a good addition to your nutrition plan, such as in a protein shake or on top of some sliced apples, but it certainly does not replace other interventions.


An alkaloid compound extracted from a variety of herbs, berberine has long been touted as an anti-diabetic agent in Traditional Chinese Medicine.

A systematic review of 14 clinical trials involving over 1,000 participants concluded that for those with type 2 diabetes, a dose of 0.5 to 1.5 grams per day of berberine could be effective in lowering both blood sugar and cholesterol.

It’s important to note that berberine can cause digestive upset, and you should work with your doctor before considering taking it, especially if you are on diabetes medication.


Chromium is a trace mineral and may also support the action of insulin. In a study of 50 subjects with type 2 diabetes, chromium picolinate supplementation improved blood-sugar control. Another small study of 60 diabetic participants showed that using milk powder fortified with chromium lowered fasting blood sugar and insulin after 16 weeks.

For those who are deficient, the repletion of chromium may also help cravings. For those taking chromium, it’s best to take it with a meal.


Fenugreek is an herb that has been promoted to help with blood-sugar control, libido support, and even milk production in breastfeeding mothers.

While it may have a minor impact on blood-sugar control due to a compound it contains called 4-hydroxyisoleucine, it can also reduce potassium levels in the blood and cause urine to have a maple smell.


Ginseng falls into the “adaptogen” category of supplements. These are herbs that are suggested to have the potential to increase mental endurance and attention, as well as support resilience to the neurological, hormonal, and immune detriments of excessive stress.

One meta-analysis concluded that in those with blood-sugar issues, ginseng supplementation (typically at a dose of 3 grams daily in Traditional Chinese Medicine) may help reduce fasting blood sugar and improve insulin resistance relatively safely. However, caution should be taken by those using diabetes medication or insulin.

You’d be hard-pressed to find a body system or function that is not grossly impacted by blood-sugar levels.

It’s critical to take control. Start by regularly assessing your fasting blood-sugar trend and hemoglobin A1C. Refuse to accept borderline levels and work with your physician and your fitness and nutrition support team to implement strategies that can help you achieve optimal ranges.

Since diabetes and prediabetes are so prevalent, it’s safe to assume that a high proportion of us are at risk of having some level of blood-sugar imbalance. Unless, of course, you manage it on purpose.


Keep the conversation going.

Leave a comment, ask a question, or see what others are talking about in the Life Time Health Facebook group.

Samantha McKinney, RD, CPT

Samantha McKinney has been a dietitian, trainer and coach for over 10 years. At first, her interests and experience were in a highly clinical setting in the medical field, which ended up laying a strong foundation for understanding metabolism as her true passion evolved: wellness and prevention. She hasn’t looked back since and has had the honor of supporting Life Time’s members and nutrition programs in various roles since 2011.

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