Intermittent Fasting and Type 2 Diabetes


What is Fasting?

Fasting is the act of not eating for significant lengths of time and began when food was scarce. However, fasting is also done spiritual, religious and health reasons. 

What is an intermittent fast?

We all fast. We fast while we sleep and break the fast with breakfast, hence the name, but going even longer periods without food can have a lot of positive outcomes. Traditional fasting is usually understood as going a full day or more without food, while intermittent fasting (IF) can be achieved in many different ways. Some people on an intermittent fast skip just breakfast and then don’t eat anything after 7 or 8 pm. Some people go an entire 24 hour period, twice a week on non-consecutive days, without food and then eat slightly larger portions the other five days. Some people skip dinner. Some greatly restrict calories for two separate days a week. There is no one way to fast intermittently. As long as we are deliberately not eating for a set period of time, we are fasting in some capacity.

The benefits of intermittent fasting

Fasting has long been known to provide health benefits like improving cholesterol and blood pressure; helping with weight loss, anxiety and depression; preventing neurodegenerative diseases like Alzheimer’s and Parkinson’s and expanding “synaptic plasticity (a biological marker of learning and memory).”[1]  So not only does fasting help us physically but mentally as well.

One of the main benefits of intermittent fasting for those living with type 2 is that it decreases visceral fat. When we fast, we take in less calories. Even when we eat normally, or slightly larger portions on our non-fasting days or during or non-fasting times, our overall caloric load is diminished, as are our glucose stores. When glucose is no longer available for energy, our body then uses ketones and our stored fat to compensate for the deficit. Eating calorically restricted (CR) diets or carb restricted diets can accomplish the same outcome, but many people find it easier to restrict food entirely for short periods of time than to eat less or avoid beloved foods at every single sitting. Intermittent fasting has also been shown to maintain lean mass and reduce fat mass more than traditional caloric restriction, meaning that muscle mass isn’t lost at the same rate with IF as it is with CR.

Will intermittent fasting slow metabolism?

Caloric restriction has been shown to lead to metabolic slowdown, where your body adjusts the amount of calories it burns to the amount you are taking in. We know this happens to some degree when we are restricting what we eat at every meal, but there is some disagreement as to whether this happens to the same degree with IF.

Some people argue that IF can actually boost metabolism, while others say it may have an even more detrimental effect on metabolism than caloric restriction. But the crux of it is that if IF helps take off fat that has become dangerous to our health, then the benefits likely outweigh the potential slowing of metabolism.

Possible risks

The good news is that IF may very well be an easier way for many people living with type 2 to get their weight back to a healthy level. The bad news is that as soon as IF was stopped, blood glucose levels reverted. Intermittent fasting, like all diets, only works for as long as it is maintained.

What we eat can become a risk when living with type 2 diabetes. This is the case with any diet we choose and intermittent fasting is no different. “The biggest downside to intermittent fasting for people with type 2 is the danger of hypoglycemia or low blood sugar. For this reason, it is recommended that type 2s who wish to follow these diets consult with a nutritionist or their healthcare practitioner, both to carefully monitor their blood sugars and to adjust medications if hypoglycemia becomes an issue.” [2] Many people report an adjustment period to this new way of eating. Initially one might experience headaches or light headedness during the fasting period. The body quickly adjusts, however,  and if IF is undertaken deliberately and with the guidance of a doctor, insulin can be lowered and perhaps even cut out entirely.

Should you try it?

There is no one-size-fits-all model of food consumption. We each have to shop around and try out various methods of eating before we settle on one that helps us keep a healthy weight and is sustainable in the long term. For those living with type 2 diabetes, intermittent fasting may very well provide us with these outcomes. 

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