Everything You Need to Know about Insulin and Fat Storage


When you hear the word insulin, what comes to mind? For most, it’s a neighbor, cousin or friend that is among the estimated 9.4% of Americans who have diabetes (9 out of 10 of which are Type 2, which is often more lifestyle driven).1,2 While, yes, the prevalence of diabetes is no doubt on the rise, not a single person is immune to the massive impact that insulin and blood sugar regulation have on body composition, longevity and overall health outcomes. Imbalances in blood sugar regulation are important to consider not only for efficient fat loss, but also due to the undeniable associations with cardiovascular disease risk, blood vessel damage, breast cancer, cognitive decline, increased levels of androgens (characteristically “male” hormones) in women and increased levels of estrogen in men, and overall risk of death.3-6

And – for a lot of us- we think we’re doing better than we actually are.

Let’s consider an angle that might feel more relatable. Does pizza always sound better to you than a chicken stir fry? After several hours without eating, do your co-workers or kids suddenly seem more irritating? Does ice cream have to go hand-in-hand with your favorite evening TV show? Do you toss and turn at night? Do you feel that, despite exercising, your belly fat just won’t budge? How is your energy after eating? Does it spike? Or does it plummet and make you wish you could take a power nap? (Surprisingly, the only thing you should feel after eating is “not hungry,” versus a change in energy level.)

If any of these apply to you, you’re not alone. Know that, while these are all surprisingly common pervasive, even they certainly are not normal. They might be a sign that you’re already on the long and insidious road to diabetes. Right now, it may be showing up as unwanted fat, fluctuating energy, and a disproportionate love of processed carbs. The good news? It’s possible to make a U-turn.

How it works

If you’re primarily interested in the “so what?” and less on the physiology, feel free to skip this section entirely and jump to the next one.

When we eat, our blood sugar rises. How much it rises depends on what we eat, how much, and in what balance. Carbohydrates such as bread, pasta, cereal, fruited yogurt, grains, brownies, chips and crackers will spike blood sugar much higher than foods that are predominantly dietary fat, protein, or fiber (think a leafy green salad topped with avocado and grass fed steak).

In response to rising blood sugar, the pancreas, a 6-inch long gland behind the stomach, releases insulin. As you might be aware, insulin lowers blood sugar, whether you have diabetes or not. (Think of that relative that manages diabetes by administering insulin around mealtime. For those of us without diabetes, our pancreas does all of the insulin administration for us). Do you ever wonder where the blood sugar goes? It does not just disappear.

If we’re in the middle of some rigorous activity, such as a triathlon, blood sugar may be put to use for energy to fuel activity. If this is not the case, it might get stored as glycogen (a storage form of carbs) in the liver or muscle. But, as is the case for most people, most of the time when not fasting or exercising intensely, glycogen stores are relatively full, so insulin converts blood sugar into body fat. And, as luck would have it, our fat stores are unlimited. (Go figure.) For this reason, insulin is referred to as an anabolic hormone, meaning it builds up instead of breaks down.

If blood sugar swings too low (which can happen if we go too long without eating, are in too much of a caloric deficit during exercise, or if the insulin release in response to eating is too high), the result can be irritability, sweating, headaches, shakiness, or nausea. The pancreas then releases insulin’s counter-hormone, glucagon, to break down stored carbohydrate and release sugar in the bloodstream.

Because excessively high blood sugar and excessively low blood sugar are both life-threatening, the body works really hard to keep blood sugar in balance. Ideally, blood sugar (and therefore insulin) oscillate in a gentle, relatively steady wave throughout the day, helping stabilize energy levels, mood and satiety. When things begin to go awry, both glucose and insulin end up with exaggerated peaks and valleys, creating excess stress, inflammation and accelerated aging.

Over time, cells start to ignore the constant bombardment of excess insulin, and the pancreas, in an ever-growing panic to keep blood sugar in check, is forced to work overtime to pump out more and more to try to get the cells to respond. This is referred to as insulin resistance. When the cells stop responding effectively to insulin, blood sugar stays high. Both insulin and blood sugar then evolve to chronically elevated states, until the pancreas eventually wears out, unable to keep up with excess insulin demands. Thus, Type 2 diabetes is born.

Looking under the hood: How do I know if I have an insulin issue?

We believe that health and disease are on a spectrum, and no one goes to bed healthy only to wake up the next day with a chronic disease like Type 2 diabetes. This entire process occurs over years, if not decades. The earlier it’s addressed, the better.

Subjective symptoms give us constant hints that something might be off and should be addressed. To boot, belly fat actually serves as one of the biggest risk factors of glucose imbalance. However, without regular, objective blood testing, it’s impossible to know your unique inside story with certainty, so testing is non-negotiable in strategically addressing long term health and success.7 That being said, it’s not as simple as checking blood sugar levels alone, as even the “normal” range of blood glucose on conventional tests may not be good for heart health.8 Plus, we’re often not told to start watching blood sugar until fasting levels are over 100 mg/dL. However, it’s been found that, even when fasting blood glucose is in-range, every point above 84 mg/dL can increase diabetes risk by a whopping 6%!9  It goes without saying that a “normal” fasting blood sugar level may not tell us much, and by the time it rises, it may be too late.10 

Luckily, other markers can serve as warning signs that it’s time to take more action. In particular, C-reactive protein (a marker of inflammation), ferritin (an iron storage marker that can also spike when something is wrong) and Hemoglobin A1C (a 3-month marker of blood sugar regulation that tests how much glucose is “stuck” on one of our blood proteins) can all serve as signs of insulin resistance.11 When testing these, remember that the reference range may be normal, but may not be optimal. Most laboratory reference ranges are determined by finding the average result and extending out two standard deviations to set the upper and lower limits, instead of determining what the range for true health really could be. If you’re on the upper end of the reference range on any of those three markers, be sure to discuss a plan with your doctor.

In addition, getting a better understanding of insulin levels (remember, it’s the main hormone that promotes fat storage) by testing C-peptide can be eye-opening.12 Take note, C-peptide is released in the same amounts and at the same times as insulin, but with a longer half-life. It may be a more stable and reliable 

measurement than direct insulin itself, and aiming for an upper limit goal of 2.5 ng/mL may be prudent, as suppression of insulin is associated with weight loss and a reduction in cravings.13 Together with regular fasting glucose measurements, these indicators can provide you the insight you need to put together a more targeted action plan with your health care team.

What to do

While the deleterious effects of blood sugar imbalances seem all doom and gloom, the amazing news is that we actually have a lot of control over how the body manages glucose and insulin. Here are my eight favorite strategies to help reclaim the balance:

  • Eat a diet that is high in fiber, as this can blunt the blood sugar rise from meals.14 Ideally, most of the fiber should come from vegetables, berries, legumes and lentils versus processed grains, such as whole wheat bread or cereal. Aim for a minimum of 25 grams or more daily.
  • Build muscle mass by lifting weights at least three times weekly and eating 1 to 2 palms of high- quality protein per meal, such as pastured eggs or poultry, wild caught fish, grass fed red meat, or a trusted protein powder if you’re in a pinch for time. Muscle mass is inversely proportional to insulin resistance and diabetes; anyone who is “skinny fat,” ie- appropriate body weight but with low muscle mass, is still at risk.15  It’s even been found that a lack of strength training itself can lead to loss of insulin sensitivity.16 Plus, weight loss that results from exercise is extremely beneficial for energy production and suppression of unneeded blood sugar production from liver carbohydrate stores.17 And for anyone that is afraid of getting “bulky,” know that a body builder type look is extremely difficult, if not impossible, to achieve with a regular strength training program. To boot, skeletal muscle maintenance has been found to be a non-negotiable in addressing insulin resistance.18
  • Don’t be a sitter. Long periods of sitting are no friend to blood sugar balance. Moving around at least once per hour is a good rule of thumb, and adding in bouts of rigorous activity, even for short periods of time, such as sprint intervals, can be largely beneficial. These strategies can be part of a broader program to address insulin resistance and its role in weight regain.19
  • Magnesium is a mineral that is critical for muscle and nerve function and bowel regularity that many of us could stand to optimize. It’s found in leafy green veggies, nuts, beans and pure cocoa, and it’s used more quickly in those who are active or chronically stressed or both. The bonus is that oral supplementation has been found to reduce insulin resistance.20 Because it’s a notoriously relaxing mineral, consider taking a few caps of it in the evening. A lot of my clients report that it eases evening leg cramps after a couple of weeks too.
  • Limit fructose (or “fruit sugar”) before workouts. Most of us know to keep processed carbohydrates out of the diet, but this is especially important before workouts to help allow for more efficient fat burn during exercise. However, many might not know that a particular kind of sugar, fructose, is also important to avoid pre-workout, even if the overall balance is low carb.21 Higher fructose items to limit around exercise include all juice, cherries, mangos, pears, apples, grapes and watermelon.
  • Don’t fear fat. For those with diabetes, a high carbohydrate diet (compared to higher fat diet), actually progressed the underlying imbalance and raised “bad” cholesterol and triglycerides.22 For heart health, note that lower carbohydrate diets (often higher in fat) have been shown to be beneficial, whether or not weight loss was associated with the approach, whereas lower fat diets show heart health benefits primarily if they are accompanied with weight loss.23 In addition, omega-3 fatty acids and supplementation are critical in balancing the body’s inflammation levels.24 Takeaway? Ensure you have about a thumb-sized serving of unprocessed fat at each meal. Healthy fat from wild-caught salmon and fatty fish, pure olive oil, raw nuts and seeds, and avocado are all great options.
  • Moderate your carbs, but don’t go too low for too long. It’s pretty well-known that a carbohydrate restricted diet, and the resulting weight loss, can improve insulin sensitivity.25 As a result, keto (short for a “ketogenic diet”) has taken off as the latest fad. This approach is extremely low in carbohydrate, high in fat, and moderate in protein, and it forces the body to produce a type of fuel called a ketone body. The research on it is really interesting, and its therapeutic effects do have a time and a place. However, drones of people are hopping on long-term ketogenic diets and relying on their social media friends to tell them how to safely execute it. There are multiple issues with this approach, but the one that surprises people the most is that, over time, keto can actually contribute to insulin resistance and glucose imbalances. Except under the direction of a qualified medical practitioner, keto should be short term (2 to 6 weeks, in most cases). Over time, it can actually erode the ability to properly process carbohydrates.26-28  Work with your doctor to determine if a ketogenic approach is right for you, and if so, for what duration. Otherwise, moderate your carbohydrate intake by considering 9 to 11 daily servings of non-starchy vegetables and some fruit as your primary source, and aim to include real-food starches (such as beans, lentils, potatoes, and winter squash) fearlessly and in amounts that are appropriate for your activity levels. The more active you are, generally the more carbohydrate your body can metabolically tolerate.
  • Manage stress and sleep habits. The more sleep and stress are researched, the more I am convinced that managing both is the real foundation to a healthy metabolism. Without proper sleep, it’s difficult for the body to keep blood sugar levels stable.29 Even one night of insufficient sleep can contribute to insulin resistance and an increase in blood sugar from release of stored carbohydrates.30 When it comes to stress, one of the first-line responses from our bodies is to release cortisol, a hormone that raises blood sugar. The solution here is not to get rid of all stress (we know that’s unrealistic), but to manage it purposefully and to be mindful of the body’s cumulative stressors, which include not just relationships, family and work demands –  but also exercise, poor food choices and yes, lack of sleep. Aim for at least eight hours of sleep nightly, and when perceived stress ramps up, it’s even more important to make healthy nutrition choices and take a balanced approach in exercise.

There you have it– everything you wanted to know about insulin and fat loss. As you can see, it’s a big topic that deserves the utmost attention when working toward your health and fitness goals. Without proper blood sugar and insulin regulation, attaining your optimal body composition, mental acuity, and quality of life is nearly impossible. Be sure to test your body’s functioning through assessment of both symptomology and blood work regularly and often, all while focusing on an unprocessed foods diet that is high in plants and quality protein and an exercise routine that includes regular resistance training. While insulin imbalances may be the root of trouble losing fat (and a long list of health maladies), we have more control over the outcome than many of us realize.

Have questions about your health or blood sugar? Feeling like you’re not seeing results and need some support? Interested in learning how a coach can help you implement habits that are supportive of balanced blood sugar? Reach out to our team of dietitians any time at weightloss@lt.life.


In health, Samantha McKinney — Life Time Lab Testing Program Manager

This article is not intended for the treatment or prevention of disease, nor as a substitute for medical treatment, nor as an alternative to medical advice. Use of recommendations in this and other articles is at the choice and risk of the reader.


  1. http://www.diabetes.org/diabetes-basics/statistics/
  2. https://www.medicalnewstoday.com/releases/281924.php
  3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3680586/
  4. https://www.ncbi.nlm.nih.gov/pubmed/21115859
  5. https://www.ncbi.nlm.nih.gov/pubmed/18261857
  6. https://www.ncbi.nlm.nih.gov/pubmed/8932921
  7. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4376197/
  8. https://www.ncbi.nlm.nih.gov/pubmed/10333902
  9. https://www.ncbi.nlm.nih.gov/pubmed/18501234
  10. https://www.medicalnewstoday.com/releases/281924.php
  11. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3083884/
  12. https://www.ncbi.nlm.nih.gov/pubmed/23316320
  13. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1490021/
  14. https://www.ncbi.nlm.nih.gov/pubmed/23218116
  15. https://www.ncbi.nlm.nih.gov/pubmed/21778224
  16. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2343294/
  17. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4625541/
  18. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4853222/
  19. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5519190/
  20. https://www.ncbi.nlm.nih.gov/pubmed/21205110
  21. https://www.ncbi.nlm.nih.gov/pubmed/22081046
  22. https://www.ncbi.nlm.nih.gov/pubmed/7848401
  23. https://www.ncbi.nlm.nih.gov/pubmed/16790045
  24. https://www.ncbi.nlm.nih.gov/pubmed/18065585
  25. https://www.ncbi.nlm.nih.gov/pubmed/12761364
  26. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2903931/
  27. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2980360/
  28. https://www.ncbi.nlm.nih.gov/pubmed/20427477
  29. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3767932/
  30. https://www.ncbi.nlm.nih.gov/pubmed/20371664

Source link


Please enter your comment!
Please enter your name here