How to improve your insulin response
Let’s talk about insulin
Insulin is a hormone secreted by the pancreas in response to a rise in blood sugar levels. Although insulin is most known for its role in regulating blood glucose levels, it also influences fat and protein metabolism (more on this in a moment).
When you eat a carbohydrate containing meal your blood glucose levels will rise, causing the pancreas to release insulin to normalise blood glucose levels. It is an elegant system and, when working effectively, helps to maintain healthy levels of blood sugar.
When things go amiss
Sometimes cells will stop responding to insulin correctly, meaning that the pancreas produces more insulin to normalise blood sugar levels. We call this condition insulin resistance.Over time cells can become increasingly resistant to the effects of insulin: causing chronic rises in both insulin and blood glucose levels. This can result in the pancreas becoming damaged from overuse, leading to decreased insulin production. The resultant rise in blood sugar levels will be diagnosed as type 2 diabetes if levels exceed a certain threshold.
Why do cells become insulin resistant?
Overconsumption of calories and the carrying of excess body fat can cause a rise in the level of free fatty acids in the blood. This is particularly the case with visceral fat (the fat found around organs) which has been shown to release fatty acids and inflammatory hormones, which facilitate insulin resistance, into the blood.
The majority of current research points to the prevalence of high amounts of free fatty acids in the blood as the major culprit in the development of insulin resistance.
Diabetes is not the only concern
The development of type 2 diabetes isn’t the only concern that flows from insulin resistance.
Metabolic syndrome
Metabolic syndrome, characterised by high blood triglycerides, high blood pressure, excess abdominal fat, high blood sugar and low HDL (good) cholesterol levels, can also develop out of insulin resistance.
Weight gain
Insulin promotes the reduction of blood glucose levels through several mechanisms. Notably, it will switch on mechanisms for the storage of body fat (lipogenesis) and switch off mechanisms for the utilisation of body fat as energy (lipolysis). It is for this reason that insulin resistant individuals are predisposed to weight gain far greater than insulin sensitive individuals.
Others
Heart disease, non-alcoholic fatty liver disease, polycystic ovarian syndrome, Alzheimer’s disease, and various form of cancer have all been linked to high levels of insulin resistance.
At risk groups
Inactive individuals, particularly those who are overweight or obese are most at risk. However there is some evidence certain ethnic groups (black, Hispanic and Asian) may also be at increased risk for genetic and cultural reasons.
What can I do?
We all lie on a spectrum of insulin sensitivity to insulin resistance. Fortunately, there are a number of simple lifestyle changes one can implement to increase their insulin sensitivity and move away from potentially dangerous levels of insulin resistance.
NOTE – if you are diabetic consult your physician before engaging in dietary or lifestyle changes.
Exercise
This is likely the most effective method for quickly improving insulin sensitivity. (19) In many cases results flowing after only a few weeks of engagement in exercise. Of particular value in this context may be weight bearing exercise, as individuals with larger amounts of muscle mass tend to utilise carbohydrate more effectively.
Although significant, it should be noted that exercise alone will not likely be an effective way of improving insulin sensitivity in the long term. However, when combined with dietary interventions, long term results will likely result.
Reduce sugar intake
If your ability to effectively regulate blood sugar is compromised it follows that there will be benefit to reducing sugar intake. Once insulin sensitivity is increased sugar can then be reintroduced into the diet gradually. (Although it is generally recommend that a healthy diet will contain minimal processed and refined sugars)
Quit smoking
Contrary to the cultural adage that smoking ‘keeps you thin’ - smoking has been proven to increase insulin resistance and lead to weight gain over the long term.
Improve sleep and reduce stress
Easier said than done I know (as I write this I have an 8 month old daughter who seems to have decided sleep is for the weak). However, it is worth noting that reducing stress and improving sleep quality have both been shown to improve insulin sensitivity.
Intermittent Fasting
Intermittent fasting – where individuals restrict their food intake to a pre-determined ‘eating window’ – has been shown to be efficacious in increasing insulin sensitivity. In my experience this tends to be the most effective and most sustainable method of making meaningful change in this area. However, please be cautious, many of the benefits proposed by internet and commercial proponents of intermittent fasting are often overblown and not fully backed up by current research. (it will not fix all of your health problems while cleaning your house and doing your taxes)
For full disclosure, I use intermittent fasting as part of my eating pattern. I find it does wonders for my energy levels and helps me maintain a healthy weight with ease. If you wish to give it a try I would recommend a 16/8 fast where you eat all your daily food in an 8 hour window, 12pm to 8pm for example. My experience is that this works brilliantly for many, less well for some. So if you try it and don’t find benefit it simply might not be the best eating pattern for you.
Low-carbohydrate diets
Likewise, low carbohydrate diets (eg. atkins or keto) can be very effective at improving insulin sensitivity. However, in my experience, very low carbohydrate diets tend to be unsustainable for a long period of time. Further, if not curated effectively they often end up being deficient in various nutrients and essential dietary components - most notably fibre. I would recommend utilising a low carbohydrate eating plan for a short period of time to gain desired effect, and then begin introducing complex carbohydrates back into the diet.
My personal experience
My anecdotal experience working with clients suggests that a multitude of benefits will flow from focusing on improving insulin response. On the flip side, an insulin resistant client will struggle to manage hunger, energy levels and maintain a healthy weight.
If you are someone who feels lethargic often, craves sugary foods regularly and puts on weight easily it is possible you may lie somewhere on the insulin resistant end of the spectrum. It may be valuable to implement a few focused changes to your dietary habits and lifestyle to reap the benefits of insulin sensitivity and avoid the potential of allowing the problem to develop into type 2 diabetes.
Feed the life you want to lead,
Duncan
References;
Adeyemi, Olufunmilayo & Adeneye, Adejuwon. (2012). Phytotherapy of Hypertension and Diabetes Mellitus.
Guo ZK. Intramyocellular lipid kinetics and insulin resistance. Lipids Health Dis. 2007;6:18. Published 2007 Jul 24. doi:10.1186/1476-511X-6-18
Kelley DE, Goodpaster BH. Skeletal muscle triglyceride. An aspect of regional adiposity and insulin resistance. Diabetes Care. 2001 May;24(5):933-41.
Yu C, Chen Y, Cline GW, Zhang D, Zong H, Wang Y, Bergeron R, Kim JK, Cushman SW, Cooney GJ, Atcheson B, White MF, Kraegen EW, Shulman GI. Mechanism by which fatty acids inhibit insulin activation of insulin receptor substrate-1 (IRS-1)-associated phosphatidylinositol 3-kinase activity in muscle. J Biol Chem. 2002 Dec 27;277(52):50230-6.
Paolisso G, Tataranni PA, Foley JE, Bogardus C, Howard BV, Ravussin E. A high concentration of fasting plasma non-esterified fatty acids is a risk factor for the development of NIDDM. Diabetologia. 1995 Oct;38(10):1213-7.
Danielsson A, Fagerholm S, Ost A, et al. Short-term overeating induces insulin resistance in fat cells in lean human subjects. Mol Med. 2009;15(7-8):228-234. doi:10.2119/molmed.2009.00037
Erdmann J, Kallabis B, Oppel U, Sypchenko O, Wagenpfeil S, Schusdziarra V. Development of hyperinsulinemia and insulin resistance during the early stage of weight gain. Am J Physiol Endocrinol Metab. 2008 Mar;294(3):E568-75.
Bergman RN, Kim SP, Catalano KJ, Hsu IR, Chiu JD, Kabir M, Hucking K, Ader M. Why visceral fat is bad: mechanisms of the metabolic syndrome. Obesity (Silver Spring). 2006 Feb;14 Suppl 1:16S-19S.
Kodama K, Tojjar D, Yamada S, Toda K, Patel CJ, Butte AJ. Ethnic differences in the relationship between insulin sensitivity and insulin response: a systematic review and meta-analysis. Diabetes Care. 2013 Jun;36(6):1789-96.
Haffner SM, D'Agostino R, Saad MF, Rewers M, Mykkänen L, Selby J, Howard G, Savage PJ, Hamman RF, Wagenknecht LE, et al. Increased insulin resistance and insulin secretion in nondiabetic African-Americans and Hispanics compared with non-Hispanic whites. The Insulin Resistance Atherosclerosis Study. Diabetes. 1996 Jun;45(6):742-8.
Reaven GM. The insulin resistance syndrome: definition and dietary approaches to treatment. Annu Rev Nutr. 2005;25:391-406.
Scheen AJ. Pathophysiology of type 2 diabetes. Acta Clin Belg. 2003 Nov-Dec;58(6):335-41.
Ginsberg HN. Insulin resistance and cardiovascular disease. J Clin Invest. 2000;106(4):453-458. doi:10.1172/JCI10762
Ford ES. Risks for all-cause mortality, cardiovascular disease, and diabetes associated with the metabolic syndrome: a summary of the evidence. Diabetes Care. 2005 Jul;28(7):1769-78.
Bugianesi E, Moscatiello S, Ciaravella MF, Marchesini G. Insulin resistance in nonalcoholic fatty liver disease. Curr Pharm Des. 2010 Jun;16(17):1941-51.
Diamanti-Kandarakis E. Insulin resistance in PCOS. Endocrine. 2006 Aug;30(1):13-7.
Watson GS, Craft S. The role of insulin resistance in the pathogenesis of Alzheimer's disease: implications for treatment. CNS Drugs. 2003;17(1):27-45.
Arcidiacono B, Iiritano S, Nocera A, Possidente K, Nevolo MT, Ventura V, Foti D, Chiefari E, Brunetti A. Insulin resistance and cancer risk: an overview of the pathogenetic mechanisms. Exp Diabetes Res. 2012;2012:789174.
Borghouts LB, Keizer HA. Exercise and insulin sensitivity: a review. Int J Sports Med. 2000 Jan;21(1):1-12.
Attvall S, Fowelin J, Lager I, Von Schenck H, Smith U. Smoking induces insulin resistance--a potential link with the insulin resistance syndrome. J Intern Med. 1993 Apr;233(4):327-32.
Krebs JD, Bell D, Hall R, Parry-Strong A, Docherty PD, Clarke K, Chase JG. Improvements in glucose metabolism and insulin sensitivity with a low-carbohydrate diet in obese patients with type 2 diabetes. J Am Coll Nutr. 2013;32(1):11-7.
Volek JS, Sharman MJ, Gómez AL, DiPasquale C, Roti M, Pumerantz A, Kraemer WJ. Comparison of a very low-carbohydrate and low-fat diet on fasting lipids, LDL subclasses, insulin resistance, and postprandial lipemic responses in overweight women. J Am Coll Nutr. 2004 Apr;23(2):177-84.
McAuley KA, Hopkins CM, Smith KJ, McLay RT, Williams SM, Taylor RW, Mann JI. Comparison of high-fat and high-protein diets with a high-carbohydrate diet in insulin-resistant obese women. Diabetologia. 2005 Jan;48(1):8-16. doi: 10.1007/s00125-004-1603-4. Epub 2004 Dec 23. Erratum in: Diabetologia. 2005 May;48(5):1033.
Li L, Li X, Zhou W, Messina JL. Acute psychological stress results in the rapid development of insulin resistance. J Endocrinol. 2013 Apr 15;217(2):175-84.
Donga E, van Dijk M, van Dijk JG, Biermasz NR, Lammers GJ, van Kralingen KW, Corssmit EP, Romijn JA. A single night of partial sleep deprivation induces insulin resistance in multiple metabolic pathways in healthy subjects. J Clin Endocrinol Metab. 2010 Jun;95(6):2963-8.
Wilcox G. Insulin and insulin resistance. Clin Biochem Rev. 2005;26(2):19-39.
Keshel TE, Coker RH. Exercise Training and Insulin Resistance: A Current Review. J Obes Weight Loss Ther. 2015;5(Suppl 5):S5-003. doi:10.4172/2165-7904.S5-003
Cho Y, Hong N, Kim KW, et al. The Effectiveness of Intermittent Fasting to Reduce Body Mass Index and Glucose Metabolism: A Systematic Review and Meta-Analysis. J Clin Med. 2019;8(10):1645. Published 2019 Oct 9. doi:10.3390/jcm8101645
Stockman MC, Thomas D, Burke J, Apovian CM. Intermittent Fasting: Is the Wait Worth the Weight?. Curr Obes Rep. 2018;7(2):172-185. doi:10.1007/s13679-018-0308-9