Factors that affect blood sugars

Poor dietary choices

High sugar foods and refined carbohydrates like sugary snacks, white bread, pastries and processed cereals can cause rapid spikes in blood sugar levels. These foods are quickly digested and absorbed, leading to a surge of glucose in the bloodstream. The body reacts by releasing a large amount of insulin to bring blood sugar levels down. Regularly consuming fizzy drinks, energy drinks, or even fruit juices can also spike blood sugars quickly. While insulin works to lower blood sugar, this quick action can cause levels to drop too low, leaving you feeling tired, irritable, and craving more sugar – a vicious cycle known as the “blood sugar rollercoaster”.

Meal timing and portion sizes

Skipping meals or eating large portions at irregular times can cause blood sugar to fluctuate dramatically. Eating late at night can interfere with insulin sensitivity and lead to higher fasting blood sugar in the morning.

Physical activity

Lack of exercise and being sedentary reduces your body’s ability to use glucose for energy, leading to higher blood sugar levels. Conversely, intense exercise without proper nutrition can cause blood sugar to drop too low, especially in people prone to hypoglycaemia. 

Insufficient sleep

Poor sleep or insufficient rest increases insulin resistance, making it harder for your body to regulate blood sugar. It also raises cortisol, a stress hormone that elevates blood sugar.

Erratic sleeping hours such as working night shifts disrupts circadian rhythms, which play a role in glucose metabolism.

Stress levels

Long-term stress triggers the release of cortisol and adrenaline, which increase blood sugar levels as part of the “fight or flight” response. Stress often leads to emotional eating and consuming comfort foods high in sugar or fat, further impacting blood sugar balance. 

Dehydration

Low water intake can raise blood sugar because the body produces more concentrated blood, making glucose levels appear higher.

Drinking alcohol and caffeine

Excessive alcohol can cause blood sugar imbalances, either spiking or dropping levels, depending on the type and amount consumed. It also interferes with the liver’s ability to regulate glucose. Similarly, high caffeine intake can temporarily raise blood sugar by stimulating adrenaline release, especially in individuals with insulin resistance or diabetes. Sugary coffee drinks and added sweeteners can worsen blood sugar spikes.

Smoking

Nicotine disrupts blood sugar balance by increasing insulin resistance, making it harder for glucose to enter cells, and stimulating the release of stress hormones like cortisol, which raises blood sugar levels. Smokers also face higher risks of chronic inflammation and oxidative stress, both of which worsen insulin sensitivity and contribute to the development of type 2 diabetes.

Compromised gut health

Gut health is vital for blood sugar regulation, as gut bacteria help process the food we eat, produce key metabolites and support insulin sensitivity. An unhealthy gut can lead to inflammation, insulin resistance and poor glucose control. A compromised gut lining (leaky gut) also allows harmful substances into the bloodstream, further disrupting blood sugar balance.