Is 16/8 intermittent fasting dangerous for people with type 2 diabetes? Unfortunately, it can be, but they can also benefit from it, as intermittent fasting lowers blood sugar, improves insulin resistance, reduces oxidative stress and inflammation, and lowers blood pressure. Certain precautions can avoid dangerous hypoglycemia.
16/8 intermittent fasting is a popular weight-loss method. However, people who start with intermittent fasting also soon experience better health and well-being.
If you want to learn more about the benefits of intermittent fasting, we invite you to join our intermittent fasting community for women only.
People with type 2 diabetes have many health issues, and looking at the health benefits of intermittent fasting, it seems that they could benefit from it.
However, you often hear that people with diabetes are not allowed to practice intermittent fasting because it is dangerous for them.
Is that true?
Diabetes is associated with many health issues. In fact, 16/8 intermittent fasting positively influences many diabetes markers (1).
You probably know insulin as a blood sugar-lowering hormone that diabetes patients inject to control their blood sugar (2).
Many people think that type 2 diabetes patients need insulin because they don’t produce enough insulin. This is only partially correct. People with type 2 diabetes have much higher insulin levels than healthy people. At the same time, they need much more insulin to regulate their blood sugar. So, the reason why they need external insulin is that their bodies require larger quantities of the hormone.
You can compare this to the relationship between income and monthly expenses. People with a high monthly salary usually have higher expenses than people with a low income.
As a student, your expenses are low, and a monthly income of 1,000 USD is a lot of money.
However, when you have a mortgage to pay, have a car, and a family to feed, you won’t be able to survive with 1,000 USD per month. Maybe you earn 5,000 USD per month and still struggle to pay your bills. Despite having five times more money than during your time as a student, you may have bigger financial problems because your expenses grew disproportionately.
People with type 2 diabetes need much more insulin because of insulin resistance (3). That means that cells become less sensitive to insulin and only take up glucose from the blood when insulin levels skyrocket.
Unfortunately, insulin resistance is caused by constantly high insulin levels. At the same time, insulin resistance increases the need for insulin, which forces the pancreas to produce more insulin. This makes insulin resistance even worse–a vicious cycle.
16/8 intermittent fasting breaks the cycle by decreasing insulin levels in between meals.
High blood sugar is the primary symptom of type 2 diabetes.
By improving insulin resistance, intermittent fasting also lowers blood sugar. As cells become more sensitive to insulin, they take up sugar more easily.
For this reason, 16/8 intermittent fasting can improve blood sugar within a few months or even weeks (4).
People with diabetes know that they benefit from losing weight. The problem is that diabetes makes weight loss more difficult.
That’s not surprising. Insulin is not only a blood sugar-lowering hormone but also a fat-storage hormone. High levels of a fat-storage hormone are a bit counterproductive when it comes to fat loss.
16/8 intermittent fasting, on the other hand, makes weight loss easier because it lowers the levels of the fat-storage hormone insulin (5).
High blood sugar causes oxidative stress. Oxidative stress, in turn, creates free radicals that damage proteins, cell membranes, and even our genetic information–our DNA. In short, free radicals attack pretty much everything and cause much damage.
You can compare oxidative stress to a drunk, violent person who randomly attacks everything around him, and causes much harm.
This damage attracts immune cells whose job is to clear damaged cells, resulting in inflammation. For this reason, oxidative stress always causes inflammation.
Diabetes patients are known to have high levels of oxidative stress and inflammation. Because 16/8 intermittent fasting lowers blood sugar, it also improves these two parameters (4, 6).
Diabetes patients are at high risk of cardiovascular disease (CVD). Cholesterol levels are seen as a marker to assess the CVD risk. This is the reason why your doctor is worried when your cholesterol is too high.
There are, however, a few misconceptions about cholesterol. First of all, cholesterol alone is not a good marker to assess the CVD risk. Second, even LDL cholesterol, also called the “bad” cholesterol, is not a good marker.
New research suggests that HDL (the “good” cholesterol) and triglycerides (fatty acids in the blood) are better markers. HDL should be high and triglycerides low. 16/8 intermittent fasting increases HDL levels and decreases triglycerides and therefore seems to lower the CVD risk (7, 8).
Hypertension, also known as high blood pressure, is another prominent symptom of type 2 diabetes. Hypertension damages blood vessels and thereby increases the CVD risk.
Hypertension is often a consequence of insulin resistance. By improving insulin resistance, 16/8 intermittent fasting also normalizes blood pressure (9).
16/8 intermittent fasting is a very powerful method to get diabetes under control. In people without diabetes, it can help to prevent it.
However, because intermittent fasting has such a strong blood sugar-lowering effect, it can also be dangerous. Hypoglycemia, or low blood sugar, is a life-threatening situation.
If you want to get your diabetes under control with 16/8 intermittent fasting, make sure to:
If you want to read more about type 1 diabetes and intermittent fasting, you may be interested in reading our other article : "Can diabetics do intermittent fasting".
1. Munoz-Hernandez L, Marquez-Lopez Z, Mehta R, Aguilar-Salinas CA. Intermittent Fasting as Part of the Management for T2DM: from Animal Models to Human Clinical Studies. Curr Diab Rep. Mar 12 2020;20(4):13. doi:10.1007/s11892-020-1295-2
2. Wilcox G. Insulin and insulin resistance. Clin Biochem Rev. May 2005;26(2):19-39.
3. Freeman AM, Pennings N. Insulin Resistance. StatPearls. 2021.
4. Sutton EF, Beyl R, Early KS, Cefalu WT, Ravussin E, Peterson CM. Early Time-Restricted Feeding Improves Insulin Sensitivity, Blood Pressure, and Oxidative Stress Even without Weight Loss in Men with Prediabetes. Cell Metab. Jun 5 2018;27(6):1212-1221 e3. doi:10.1016/j.cmet.2018.04.010
5. Przulj D, Ladmore D, Smith KM, Phillips-Waller A, Hajek P. Time restricted eating as a weight loss intervention in adults with obesity. PLoS One. 2021;16(1):e0246186. doi:10.1371/journal.pone.0246186
6. Moro T, Tinsley G, Bianco A, et al. Effects of eight weeks of time-restricted feeding (16/8) on basal metabolism, maximal strength, body composition, inflammation, and cardiovascular risk factors in resistance-trained males. J Transl Med. Oct 13 2016;14(1):290. doi:10.1186/s12967-016-1044-0
7. McAllister MJ, Pigg BL, Renteria LI, Waldman HS. Time-restricted feeding improves markers of cardiometabolic health in physically active college-age men: a 4-week randomized pre-post pilot study. Nutr Res. Mar 2020;75:32-43. doi:10.1016/j.nutres.2019.12.001
8. Moon S, Kang J, Kim SH, et al. Beneficial Effects of Time-Restricted Eating on Metabolic Diseases: A Systemic Review and Meta-Analysis. Nutrients. Apr 29 2020;12(5)doi:10.3390/nu12051267
9. Gabel K, Varady KA. Current research: effect of time restricted eating on weight and cardiometabolic health. J Physiol. Oct 1 2020;doi:10.1113/JP280542