Is Intermittent Fasting Safe?

Check out this answer from Consensus:

Intermittent fasting is generally safe and effective for weight loss and metabolic health improvement in individuals with obesity and T2DM. It shows promise in improving cardiometabolic markers and glycemic control, with similar safety profiles to continuous calorie restriction diets. However, the long-term safety and adherence to IF regimens remain uncertain, necessitating further large-scale studies. Special populations and patients on medications should undertake IF under medical supervision to mitigate risks.

Intermittent fasting (IF) has gained popularity as a dietary regimen for weight loss and metabolic health improvement. However, questions about its safety, particularly for individuals with chronic conditions like diabetes, remain. This synthesis examines the safety of intermittent fasting based on multiple research studies.

Key Insights

• General Safety and Efficacy
  • Intermittent fasting is generally safe and can be implemented for weight loss and metabolic health improvement in individuals with obesity and type 2 diabetes mellitus (T2DM)1 2 3 6.
  • IF regimens are effective in reducing weight, fasting insulin levels, and blood glucose levels, with similar effectiveness to continuous calorie restriction diets1 3 6.
• Cardiometabolic Health
  • IF can improve cardiometabolic markers such as blood pressure, insulin resistance, and oxidative stress, and may lower low-density lipoprotein cholesterol and triglyceride levels, although findings are variable5 6.
• Glycemic Control in Diabetes
  • IF has similar effects on glycemic control as continuous energy-restricted diets in patients with T2DM, with no significant difference in hypoglycemic events1 3.
  • There is an increased risk of hypoglycemia in T2DM patients treated with insulin or sulfonylureas, necessitating careful monitoring3 7.
• Long-term Safety and Adherence
  • Long-term adherence to IF regimens is uncertain, and more extensive studies are needed to confirm their long-term safety and efficacy2 3 4 9.
  • Current studies are limited by small sample sizes and short durations, highlighting the need for larger, long-term randomized controlled trials2 3 4.
• Special Populations
  • IF appears to be safe for patients with multiple sclerosis, but data are too limited to draw firm conclusions2.
  • IF may have specific adverse effects and limitations for certain age and gender groups, requiring more systematic studies8.
• Clinical Guidelines and Recommendations
  • There are no established medical guidelines for managing IF in patients with diabetes, and recommendations are often based on limited data and expert opinion7.
  • IF should be undertaken under healthcare provider supervision, especially for patients on medications, to ensure safety and appropriate glucose monitoring7 10.

Is intermittent fasting safe?

Krista Varady has answered Likely

An expert from University of Illinois at Chicago in Fasting, Kinesiology

Many studies have shown that intermittent fasting is safe. It does not result in nutritional deficiencies or eating disorders. It also doesn’t have a negative effect on hormone levels, bone mass, or metabolism.

Most studies of intermittent fasting report health benefits such as reductions in cholesterol levels and blood pressure, and better blood sugar control. Taken together, intermittent fasting seems to be protective against heart disease and diabetes, with little or no negative health effects.

Is intermittent fasting safe?

Leanne Harris has answered Likely

An expert from University of Glasgow in Obesity

There have been no major side effects (adverse events) report in the literature. There have been some minor physical and psychological side effects reported in a minority of participants following intermittent fasting regimens. These include a lack of energy, headaches, feeling cold, constipation, bad breath, a lack of concentration, pre-occupation with food, and mood swings. It is important to note that these minor adverse events were in general similar to dieting every day and only sometimes reported to be more frequent in intermittent fasting programmes.

Is intermittent fasting safe?

Michelle Harvie has answered Uncertain

An expert from Manchester University Hospital Foundation NHS Trust in Breast Cancer, Fasting, Dietetics

Depends. For people with simple obesity with all normal caveats to dieting. Not recommended for children, pregnant or breast feeding women or frail elderly.

Need to seek advice if have medical conditions or taking medications as may be contra indicated or may need to adjust medications.

Is intermittent fasting safe?

Isabel Krug has answered Uncertain

An expert from University of Melbourne in Eating Disorders

I’m not a medical doctor and hence don’t know the exact health consequences of intermittent fasting on the body. I know from my work with eating disorder patients that starvation in the milder forms can cause symptoms such as headaches, weakness, tiredness, cramps and dizziness. In the more severe forms, the body enters a hypoglycemic state and confusion, irritability and increased heart-rate follow. As starvation continues, the person may experience nightmares, lack of coordination and fainting. Hence, these are all symptoms that I would assume a person undergoing a prolonged time of intermittent fasting could also present with.

Is intermittent fasting safe?

Hiba Jebeile has answered Likely

An expert from University of Sydney in Nutrition

When used under medical supervision, the research suggests that intermittent fasting is safe, without and major side effects.