Quick Answer
Yes, not eating can lower your blood sugar levels temporarily. When you don’t eat for several hours, your body starts using stored glucose for energy, which causes your blood sugar to drop. However, not eating is not a sustainable long-term strategy for managing blood sugar. You need a balanced diet to maintain healthy blood sugar levels over time.
What Causes High Blood Sugar?
Blood sugar or blood glucose levels rise after eating carbohydrates. Your body breaks down carbs into simple sugars, which enter your bloodstream. Insulin, a hormone produced by your pancreas, allows sugar to move from your blood into your cells to be used for energy.
In people with diabetes, insulin resistance prevents cells from taking in glucose properly. As a result, sugar builds up in the bloodstream. Eating large amounts of carbs or sugary foods can cause blood sugar spikes in anyone, but it is a particular problem for those with diabetes.
Main Causes of High Blood Sugar
– Eating more carbs or sugars than your body can handle
– Lack of exercise
– Being overweight
– Insulin resistance
– Type 1 or type 2 diabetes
– Certain medications
– Stress
– Illness
– Dehydration
How Does Fasting Impact Blood Sugar?
When you stop eating for several hours, your body turns to stored glucose, also called glycogen, for energy. Glycogen is found in your liver and muscles. As this reserve glucose source gets used up, your blood sugar starts to decrease.
This drop in blood sugar triggers your body to start breaking down fat and protein for fuel through a process called ketosis. As less carbohydrate fuel becomes available, ketone bodies become your main energy source. This state of fasting with ketone body production is called ketosis.
So in the short-term, fasting and restricting carbs will lower blood sugar. However, if you fast for too long, you can experience low blood sugar or hypoglycemia. Symptoms of low blood sugar include:
– Shakiness
– Sweating
– Anxiety
– Hunger
– Irritability
– Dizziness
– Tingling sensations
– Rapid heartbeat
Extremely low blood sugar can result in confusion, seizures, loss of consciousness, and even death if left untreated. People with diabetes are especially susceptible to hypoglycemia.
How Long Does it Take to Lower Blood Sugar by Fasting?
– After fasting for 8 hours, your blood sugar starts to drop.
– Within 12-16 hours of fasting, your blood sugar drops further.
– 20-24 hours into a fast, your blood sugar can reach quite low levels.
But these effects are temporary. Once you start eating carbs again, your blood sugar will spike back up.
Health Risks of Prolonged Fasting
While occasional short-term fasting can be safe for some people, extended periods of fasting can pose the following health risks:
– **Hypoglycemia** – As mentioned, low blood sugar is a potential side effect of fasting, especially if you take medication that lowers blood glucose. Mild hypoglycemia causes fatigue, mood changes, anxiety, dizziness and trembling. Severe hypoglycemia leads to confusion, seizures, loss of consciousness and coma.
– **Dehydration** – Not eating causes you to lose body water, which can lead to dehydration. Symptoms include increased thirst, dry mouth, headache, dizziness and dark urine.
– **Electrolyte imbalances** – Fasting leads to the loss of electrolytes like sodium, potassium and magnesium. This can disrupt nerve impulses and muscle function.
– **Fatigue and weakness** – Without adequate calories from carbohydrates, your body struggles to produce energy, resulting in tiredness and muscle weakness.
– **Nutrient deficiencies** – Prolonged fasting can lead to deficiencies in vitamins, minerals, protein, fiber and phytochemicals only found in whole foods. This may impair immune function and increase disease risk.
– **Gallstones** – Rapid weight loss from fasting has been linked to gallstone development. Gallstones can cause pain, nausea, vomiting and jaundice.
– **Irregular heartbeat** – Fasting may cause arrhythmias, irregular heart rhythms that increase the risk of stroke and heart failure.
– **Growth impairment** – Intermittent fasting is not advised for children and adolescents, as it may slow growth and development.
– **Binge eating** – The hunger and cravings caused by fasting may lead to episodes of binge eating once you start eating again. This can undermine blood sugar control.
Who Should Avoid Fasting
Prolonged fasting is not recommended for:
– Children and teens
– Pregnant or breastfeeding women
– Those with diabetes orblood sugar disorders
– Individuals with a history of eating disorders
– Patients on medication that may cause hypoglycemia
– Those with electrolyte abnormalities
– People who are underweight or malnourished
Healthier Ways to Lower Blood Sugar
Instead of lengthy fasting, focus on long-term lifestyle changes to stabilize blood sugar:
– **Follow a balanced, low-glycemic diet** – Emphasize non-starchy vegetables, lean protein, healthy fats, legumes, whole fruits and whole grains. Limit refined carbs, sugary foods and fruit juices.
– **Exercise regularly** – Aim for 30-60 minutes per day of moderate activity like brisk walking. Exercise makes your cells more sensitive to insulin for better blood sugar management.
– **Lose excess weight** – Carrying extra body fat worsens insulin resistance and contributes to high blood sugar. Losing just 5-10% of your body weight can improve blood glucose control.
– **Take medications as directed** – If you have diabetes, take your medications regularly to help moderate blood sugar levels. Don’t adjust dosages unless directed by your healthcare provider.
– **Manage stress** – Chronic stress causes cortisol spikes that raise blood sugar. Relaxation practices like yoga, meditation and deep breathing can blunt the effects of stress on blood glucose.
– **Get enough sleep** – Not getting 7-9 hours per night is linked to poor blood sugar regulation. Prioritize sleep consistency for better insulin sensitivity.
– **Stay hydrated** – Dehydration from inadequate fluid intake can increase blood sugar concentrations. Sip water regularly throughout the day.
Conclusion
In summary, fasting or severely restricting carbs does lower blood sugar temporarily. However, it is not a practical or safe long-term solution. Prolonged fasting can lead to dangerously low blood sugar levels along with vitamin and mineral deficiencies, dehydration, fatigue and heart rhythm abnormalities. For sustained blood sugar control, adopt eating, exercise and lifestyle habits that keep blood glucose levels balanced around the clock. Work with your doctor to find a diabetes management plan that allows you to eat balanced meals at regular intervals.