Why Does The Weather Affect Insulin Sensitivity?

Our bodies consistently change to adapt to our environment, and our insulin sensitivity changes with them. There are 42 factors that can have an influence on our blood sugar levels and the amount of insulin that has to be administered to take care of those blood sugars.


The weather is a factor that can have a huge effect on our glucose levels, but doctors never talk about it. There are 2 ways that Type 1s can react to changes in temperature outside: they either become more insulin sensitive or less insulin sensitive. The funniest part is that some T1Ds will have increased insulin needs in cold weather, but others will need more insulin in hot weather. The first of the two phenomena is more common.


There is no actual medical or academic explanation to why insulin sensitivity changes. Most doctors and researchers attribute it to less movement, a tendency towards ‘heavier’ foods, winter depression and drinking less water. However, in reality, even with absolutely no change in routine, cold weather does have an effect on insulin sensitivity.


If your insulin needs increase in the winter, like mine do, these are some potential reasons this may happen:


- Your body is more stressed in cold weather, and ‘fight or flight’ hormones are released, which will increase your body’s needs for insulin.


- The cold weather will slow down your metabolism, as we know all chemical reactions happen slower in decreased temperature, as molecule movement is slower (school-level chemistry, guys). Therefore, the entire process of transportation in the body will slow down, and insulin will need to be at a higher concentration in our blood to reach the cells in time.


- It is possible that our bodies need an increased amount of glucose to be able to keep us warm, and our liver starts releasing extra glucose throughout the day to keep the temperature up. This will mean that extra glucose, that we have not accounted for in our regular basal needs will now be floating around, and we will need more insulin to enable it to access our cells to create energy.


As I have mentioned, there is no clinical proof that the above reasons affect insulin sensitivity, but most of us do experience a change in our insulin needs when the weather changes. The first and third reasons can also be considered for people who’s insulin resistance increases in the summer. These changes remain a mystery for diabetics and medical professionals alike, but at the end of the day, if you need more insulin – give more insulin, and it does not matter why you need it.


Be attentive to your blood sugars, look for patterns and don't be afraid to make adjustments. Your blood sugar control is in your hands, and only you can truly make it work for your body. Don’t stress over why the insulin needs change too much, just address them, and note possible reasons for future reference.


None of the information in this article is intended as medical advice. Please always consult your diabetic team before making any changes to your diabetes management.