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Increasing Insulin Sensitivity is the Key to Fat Loss

insulin word cloud

When formulating a diet, one of the most important goals you should have in mind is to improve your insulin sensitivity. What is insulin sensitivity? To fully understand what it is, let’s discuss insulin and its function.

Insulin is a storage hormone. After you eat a meal, your body converts the carbohydrates into glucose. This glucose circulates the bloodstream and is used by all the cells in your body.

Insulin is the hormone that stores the extra glucose that your body doesn’t use. Your body has a limited capacity to store glycogen. A typical male will be able to store around 500 grams of glycogen.

In case you didn’t know, glycogen is what’s formed from glucose. When your body can no longer store anymore glycogen, the excess glucose is taken up by insulin and stored as fat.

Insulin sensitivity has to do with how well your cells respond to insulin. People that are highly insulin sensitive require very little insulin to store carbohydrates. By reason then, people that are insulin resistant (type II diabetics), need larger amounts of insulin to shuttle those carbohydrates around.

What this means is that when you have high insulin sensitivity, you are able to eat carbohydrates without such a large rise in insulin. When insulin is kept low enough, fatty acids can still be released.

However, once insulin gets too high, fat loss comes to a halt. People that have bombarded their bodies with high-glycemic carbohydrates and processed foods over their lifetimes have become somewhat resistant to the effects of insulin. Therefore, when they eat carbohydrates, it causes a larger release of insulin. This inhibits the release of fatty acids.

Higher insulin levels = more fat storage

Read here to find out 10 ways you can improve your insulin sensitivity for better fat loss.

Reduce Insulin Resistance

When insulin is high, fat can’t be released. For fat loss to occur, it needs an environment of low insulin, and high growth hormone. Growth hormone is a very powerful hormone that is responsible for many positive metabolic functions – one of which is the release of fatty acids.

In order to increase growth hormone levels, you need to have insulin levels low. GH and insulin levels are inversely correlated. When one is high, the other is low. So then, what are the factors that both raise and lower insulin?

Insulin is released in response to a meal that contains carbohydrates (and protein). Insulin is directly correlated to both the amount of carbohydrates (glycemic load) you eat and the GI (glycemic index) of that carb.

The GI, in short, is how quickly a particular carbohydrate is digested by the body. The more sugar you ingest, the more insulin your body releases in order to store that energy. The higher the GI of that carbohydrate, the quicker your blood sugar levels rise, and in response, your body releases more insulin to store that energy. To recap:

  • Insulin levels are low when growth hormone levels are high, and vice versa.
  • Insulin is a fat storage hormone that stores extra carbohydrates.
  • Growth hormone releases fatty acids in an environment of low insulin.
  • Insulin sensitivity is how sensitive your cells are to the effects of insulin. The more insulin you need to store those carbohydrates, the harder it’s going to be to lose fat.

We’re going to be needing those carbohydrates for our high-intensity exercise. So then, how do we ingest carbohydrates for fuel, while at the same time keep insulin low enough so that fat can still be released?

Eat Carbohydrates When Insulin Sensitivity is High

The best way to do this is both through nutrient timing, and choosing the right carbohydrates in the first place. Your insulin sensitivity is at its highest first thing in the morning, and after a workout.

This is when your body has its lowest muscle and liver glycogen, and therefore will be more receptive to soak up the carbohydrates you just ate, instead of sending out large amounts of insulin to store that glucose as fat for another time. So when formulating a meal plan with a goal of improved insulin sensitivity, try placing the bulk of your carbohydrates for your first meal and the meals around your workout.

Choosing the right food to eat will always be the easiest and most effective way to increase your insulin sensitivity. Whole foods contain fiber. Fiber helps to slow down the digestion of carbohydrates, and as a result, your body gets a nice steady feed of glucose to use instead of a large influx of sugar that causes insulin to go through the roof!

Whole foods also tend to have a lower GI. Lower GI foods cause a slower release of glucose into the bloodstream. This results in lower amounts of insulin needed to shuttle those carbohydrates around.

So, eat fruit, vegetables, legumes, potatoes, and whole grains. They are high in fiber and nutrients, and will help put your body in the optimal environment to release fat.

Don’t fight against your body. It will beat you every single time! The great news is that you can reverse the effects of insulin resistance by changing your diet and exercising. Eat the right foods, and you’ll be well on your way to regaining that fat loss advantage.

  • Lantana H.

    This is such good information. Why I haven’t I read anything like this before? Your posts are very well written. You don’t sound like a lot of bloggers who seem to be struggling for words to fill their pages. All your posts are concise and explanatory. You cut right to the chase and give your readers VERY useful information on how to not only lose weight, but how to actually live optimally. You have a gift.

    • Coach Calorie

      I appreciate the kind words Lantana!

      • julie


        I approuve, it’s a really good article, but im french and I have difficulty to understand well the objective of how to increase insuline sensitivity. Can u do me a resume ? I feel like Im doing a perfect diet, doing cardio 4times a week and im not losing fat… I don’t want to lose weight, I want to lose fat, get leaner !!!

        thanx a lot

        • Coach Calorie

          Not sure what you mean by a resume Julie. Are you incorporating strength training into your fitness program? Or are you just doing cardio?

          • marie

            hi can you tell me what the right carbs protein and fat ratio is for a 50 yr old active woman

    • Mari S.

      I am so glad I liked this page on facebook! I love the updates and interesting and informative articles you post daily! awesome info! Thanks a bunch it really helps me with my diet and exercise

      • Coach Calorie

        Glad you find it useful Mari. Thanks for reading!

  • Antonio

    Hi Tony, what would you recommend for someone who is taking diabetes medication (metformin) which is designed to supress glucose production.

    • Coach Calorie

      Antonio, anyone who is a type II diabetic needs to really focus on their carbohydrate choices. It is a must that you avoid processed foods like flour and sugar, and you could really stand to benefit from picking low glycemic carbohydrate choices. Exercise is another way to improve your insulin sensitivity.

  • Ellen

    Love your blog! This article will be especially helpful for my husband who I believe is very prone to insulin fluctuations. Thanks!

  • Donna B.

    I’m insulin resistant and take Metformin to help with that,and I have noticed that when I’m diligent about taking my medication and watching my diet that I have an easier time losing weight. I wish I’d found this article years ago when I was trying to figure out what was wrong with me, and trying to find a doctor that would help me figure it out. This is really great information, thanks for sharing it with your readers.

    • Coach Calorie

      Hey Donna, do you think you’ll ever come off the Metformin use?

  • Marina

    Hi Tony
    Incredible blog, you are amazing, you explain things so well! It’s the best “healthy book for dummies” ever! Thanks for sharing all your knowledge. I’m hopeful you will be able to help me break this plateau I am in for 3 months now… I workout 5-6 x a week (sometimes I split the training so I workout 2x in the same day), alternating constantly from early am cardio (spin or kick boxing, before breakfast usually) to weight training (different muscle groups at different days), to HIIT classes. I recently did P90X. I rest 1 x week. I noticed some changes, but I swear this abdominal fat is glued to me with super glue! It takes forever for the slighest change! I’m 140 lbs, 5’6″, eat about 1,800 cal a day (sometime a little more, sometimes a little less) split in 5 meals, drink 12-16 glasses of water a day, stick to fruits (not too much b/c of sugar), mostly vegetables, legumes, lean meats, nuts, egg whites and whey isolate shakes with almond milk. I try to eat about 140 gr of protein a day. I rarely have dairy, no white breads, startches, no coffee (I drink 3 cups of green tea a day), no pop or alcohol. Recently I added fish oil to my diet. What am I missing? My husband is constanly saying that I eat too much.. I’m actually starting to believe him.. do I?

    • Coach Calorie

      Thanks Marina. “Healthy Book for Dummies”, I should market that ;)

      I don’t think 1800 calories is necessarily too much for your activity level. What is your body fat %? If it’s already low, we might have to do some diet manipulation to get things going again, but I’ve written about breaking weight loss plateaus before. You can see that here –

      Do you have cheat meals during the week? Have you been in a constant calorie deficit for months, or do you ever increase your calories for a period of time?

      • Marina

        I will be the first in line to buy that book :). I will read the weigth loss plateu article and try those techniques. My BF is at 26% and I’m 38 yrs old. I do cheat now and then, but not constantly (maybe 2 or 3x month). I have been in a calories deficit based on the whole “if you eat less than you spend, then you will loose weight” school of thinking. After reading your article on insulin, I’m thinking that I eat carbs at the wrong time of the day. I tend to have egg whites for breakfast (with steamed kale or aspargus), sometimes oatmeal with whey (after a spin w/out) and, then protein and carbs (vegetables, brown rice, sweet potatoes) with my main meals. But I know realize I’m eating a chunk of carbs after lunch (which is when I’m at work sitting down). Again, I will read your other article closely. Thank you so much for your input. I know I’m messing up somewhere, I just can’t quite put my finger on where.

  • Alison

    Hi Tony,
    I love this post.,thank you. While I am not insulin resistant, I have struggled to grasp this concept because of the dual role that insulin plays, but you have explained it so well that now I fully understand its workings.
    Thanks again


  • Karen S

    Other than having Type II diabetes how does one know if they are insulin resistant? How does the thyroid play into this as well? After having pulminary embolism 14 month ago and putting on 30 pounds my doctors discovered an under active thyroid as a result of Hashimoto’s Disease. I am struggling to lose the 30 lbs despite careful calorie counting and resuming exercise. Any thoughts?

    • Coach Calorie

      I suppose the only way to know for sure is to test yourself. You can test your blood sugar levels at certain intervals after you eat a carb meal, or you can get blood work done to test how your blood sugar levels have been over a period of time.

      Other than that, there are other “non bloodwork tests” you can perform, although there can be other factors that affect them. The biggies are: low blood sugar or tiredness shortly after a meal, and the propensity to store abdominal fat.

      • Lmyers

        There is also Insulin level tests that can done on your blood but the Gold standard is the Insulin Challenge test done under supervision. The easiest indicator is high fasting insulin and high Triglycerides

  • raven

    How about bodybuilders who eat sugar before and after intense workout? I’m pretty sure there are some pre-workout supplements and gainers that contain 35gr sugar per serving as well as creatine and many says it’s good.

    • Coach Calorie

      That depends on what you consider “good”. Might there be some additional muscle building benefits to spiking your insulin levels post-workout? Possibly. However, I choose to put health over looks. The differences in muscle growth are minimal anyways. The important thing is to refill glycogen stores, and that can be done throughout the day with low-glycemic carbohydrates.

  • raven

    Btw, how much sugars can spike insulin?

  • Coach Calorie

    That is dependent on the individual, the glycemic index, and the glycemic load of the meal. Insulin is going to rise after a meal regardless of what you eat. If you want to keep them low, eat a meal with whole foods, fiber, healthy fats, and protein. All of these things will lower the GI of the meal.

  • Helen Harvey

    I thought insulin was the hormone that was needed to let the glucose pass from the blood to the cells, here are you saying that insulin is only used for excess glucose?

    • Coach Calorie

      Hi Helen, yes – insulin is always present in your blood. I’m talking about excess glucose being stored as fat via insulin. Ideally you want a nice steady but low level of insulin so that fatty acids can be released. Too much glucose raises insulin to levels that inhibit their release.

  • janita

    my 12 year old has had diabetes since age two. since we constantly check her blood sugar, i see firsthand how TRUE this is!! if she eats a real dessert or something fatty, no amount of insulin can counteract the load. she will be high for hours, despite our efforts. but when she eats a whole wheat sandwich and some grapes, her normal carb ratios work fine. there may be more carbs in the latter meal, but the effect on her body is completely manageable, whereas the dessert throws it into chaos. and for the exercise component, this is by far our best tool for combatting high blood sugars. it is so much MORE effective than giving insulin. we literally have her swim or run or do something active without her pump on (so no insulin coming in), and most of the time, the activity not only takes care of her high glucose, she will also need a carb snack afterwards to keep from diving too low. its amazing.

    • Coach Calorie

      Thanks Janita for sharing that real world experience. It’s amazing what can be accomplished with a good diet and physical activity.

  • Theresa Goings Cantrell

    I absolutely love, your blog. You are the most informative blog I have found. Please keep the information coming, I look forward everyday to reading your articles. Thank you!

  • Coach Calorie

    There is no “right” answer. Aim for .8-1g of protein per pound of lean body mass, eat enough carbs to fuel your activity levels, and then fill the rest with fat.

  • Laleh Asher Zar

    thank you! this is your best article yet! do you have any other suggestions on specific things to help insulin resistance, and regulate the hormones, or any supplements that will work alongside an improved diet and exercise?

    • Tony Schober

      Thanks Laleh. There’s a link in the article that you can click that will take you to another article that shows 10 ways to improve your insulin sensitivity.