Five Benefits of Intermittent Fasting

  • Nature's Source

While health trends have come and gone, fasting has withstood the test of time and continues to be an effective way to optimize health. Intermittent fasting (IF), in particular, has become one of the most popular ways to incorporate fasting into our busy schedules, due to the customizability that it offers. IF can be implemented in a few different ways:

  • Alternate Day Fasting: You are consuming either restricted or unrestricted calories every other day, alternating with a full day fast.
  • Whole Day Fasting: You are doing a full 24-hour fast for a single day or several consecutive days.
  • Time Restricted Feeding: You are limiting your window of food consumption during the day to a short period of time, 8 hours or less.

There are many health benefits to IF and they include, but are not limited, to the following:

Mood Stability

Intermittent fasting has been shown to improve mood in healthy people. In a study that observed a group of senior men (average age was 60 years) who implemented IF for a period of 3 weeks, it was found that mood scores were much improved compared to the group who maintained their regular eating habits (ie. 3 regular meals each day). At the end of the 3 weeks, the men who were part of the IF group reported reduced tension, anger and confusion, as well as improved energy, compared to the control group. They also found that their moods were more stable and were less likely to fluctuate throughout the day.

Cardiovascular Health

Heart health relies on a healthy diet consisting of healthy fats (rather than fat-free or saturated fats), adequate fiber and phytonutrients from fruits and vegetables. A healthy diet protects the blood vessels from becoming narrowed due to deposited cholesterol and reduces the risk of heart attack and stroke. IF has been shown to reduce cholesterol and total triglycerides (two biomarkers for cardiovascular health that contribute to heart disease risk) in normal weight and obese adults, in trials consisting of 3-12 weeks of alternate day fasting. Whole day fasting can reduce cholesterol by 5-20% and triglycerides by 17-50%, resulting in reduced risk for cardiovascular disease.

Weight Loss

Alternate day fasting and time restricted feeding are the most studied methods of IF specifically for weight loss. Multiple studies have shown that implementing calorie restriction on fasting days for 2 months can result in 3-7% body weight loss among groups of obese adults. Especially when paired with weight-bearing exercise, IF can help to shift the weight loss towards fat mass loss rather than muscle loss, which is important for performance athletes.

Blood Sugar Regulation

Insulin resistance has become a big health issue due to all the sugar (and hidden sugar) that’s in the typical North American diet. Insulin resistance develops when the pancreas release increasing amounts of insulin, over time, in response to the sugars (bread, pasta, pastries, cake etc.) that we consume. As a result of this, the cells within the tissues and organs of the body become less sensitive to insulin and thus, blood sugar levels remain elevated. This is the basic pathology behind Type 2 Diabetes and can result in a variety of health effects such as end-organ damage and peripheral neuropathy (loss of sensation in the extremities). Alternate day fasting has been shown to be an effective way to help manage the insulin spikes and to improve insulin sensitivity- a study reported a 25% reduction in insulin resistance following a period of IF for 2 days per week. IF can improve blood sugar metabolism as well as normalize HbA1c, a marker of chronic blood sugar dysregulation.

Cancer Prevention

Studies have shown that IF can have a positive effect in the reduction of several inflammatory biomarkers that play a role in the development of different cancers. Adipose (fat) tissue is biochemically active and releases a hormone, leptin that affects the feeling of satiety (fullness) after a meal. The more adipose tissue an individual has, the greater the amount of leptin is produced. High levels of leptin have been implicated in cancer development as it can promote uncontrolled cell division (formation of tumours). However, with weight loss through IF, and the maintenance of leaner body tissue, less leptin and more adiponectin is produced, a hormone which provides protection against cancer.

Intermittent fasting promotes many health benefits but isn’t suitable for everyone, so please consult with a physician or natural health practitioner before you begin to incorporate it into your lifestyle.

Dr. Naomi Ha is a licensed naturopathic doctor, registered with the College of Naturopaths of Ontario. She currently practices in Leslieville at Pursuit Integrative Health (1039 Gerrard St. E., Toronto) and has a special focus in reproductive and hormonal health.


Hussin NM, Shahar S, Teng NI, Ngah WZ, Das SK. Efficacy of fasting and calorie restriction (FCR) on mood and depression among ageing men.J Nutr Health Aging. 2013;17(8):674-80.

Kulovitz MG, Kravitz LR, Mermier C, Gibson AL, Conn CA, Kolkmeyer D, et al. Potential role of meal frequency as a strategy for weight loss and health in overweight or obese adults.

Mattson MP, Longo VD, Harvie M. Impact of intermittent fasting on health and disease processes.Nutr Rev. 2015 Oct;73(10):661-74 Tinsley GM, La Bounty PM. Effects of intermittent fasting on body composition and clinical health markers in humans. Nutr Rev. 2015 Oct;73(10):661-74.