The Evidence-Based Benefits of Intermittent Fasting

Fasting may lead to healthy weight management, but it also causes fundamental shifts in your body’s physiology — such as improvements in glucose regulation, blood pressure, and heart rate.

Human and animal studies explain that fasting enhances health and leads to weight loss in ways that are unrelated to a calorie deficit. IF triggers shifts in metabolic and hormonal pathways that naturally help you maintain a healthy body (including, but not limited to, weight loss).

Let’s talk about IF benefits, looking beyond just weight management and sticking to the evidence.

1. Improved Digestion

Intermittent fasting may improve gut health and digestion by reducing inflammation, as well as strain on your digestive system. Intermittent fasting may even have a positive effect on your gut microbiome. (1)

Many of my patients have irritable bowel syndrome, inflammatory bowel disease, or simple but frequent indigestion. Elimination diets are effective when they are temporary, but so many are constantly trying to find the food group that’s triggering digestive issues.

I often recommend a fasting protocol for digestive issues. Studies have shown that IF lowers gut inflammation and helps improve inflammatory gut disorders such as Crohn’s disease, ulcerative colitis, and IBS. (2)

For more, check out my book, Intuitive Fasting.

2. Better Brain Health

Intermittent fasting may lead to better brain health, possibly due to decreased inflammation and oxidative stress. IF’s antioxidant and anti-inflammatory properties may even increase lifespan by improving brain function, cutting down on brain fog, and reducing your risk of age-related diseases.

I was pleasantly shocked to learn about the strong preclinical evidence that shows how fasting can prevent and slow down the progression of conditions like Parkinson’s and Alzheimer’s disease. (3)

IF increases your brain cells’ ability to resist stress. It also stimulates autophagy, which boosts mitochondrial function, antioxidant defenses, and DNA repair. Fasting also supports neuroplasticity, which is the brain’s ability to reorganize itself and form new neural connections. (4)

LISTEN: Dr. Jason Fung: Fasting Health Benefits & Myths, Reestablishing Ancestral Health Habits + The Best Foods To Eat When Breaking Your Intermittent Fasts

3. Better Blood Sugar Control

Intermittent fasting may more effectively regulate your blood sugar levels. People with diabetes and prediabetes may benefit from IF’s impact on insulin resistance, but remember to talk to your healthcare provider before making lifestyle changes to treat diabetic conditions.

The CDC estimates that about half of the US is prediabetic or diabetic. I did not mistype that — 50 percent of Americans have a major blood sugar problem. What’s more, many of these people don’t know they have type 2 diabetes!

When patients come in with blood sugar problems, I like to recommend IF due to its potent ability to improve insulin resistance. (5)

Researchers from the University of Alabama conducted a study on the impact of fasting on obese men with prediabetes. They compared restricting eating to an 8-hour period per day to a 12-hour period. Both groups maintained the same weight after 5 weeks, but the 8-hour eating window group had dramatically lower insulin levels and significantly improved insulin sensitivity. (6)

Read More: What Is Intuitive Eating?

4. Weight Management

Although it’s not the only reason you should fast intermittently, healthy weight management is a huge benefit of fasting therapy. IF may also reduce your risk for the many chronic diseases that come with high body fat.

IF is an efficient dietary plan for people with obesity to achieve weight loss and for everyone to maintain a healthy weight. Some researchers conclude IF is especially effective in the short-term, as in 1 to 3 months. (7)

A recent systematic review found that IF helped overweight and obese people lose 0.8% to 13.0% of their baseline weight. These researchers were optimistic, but they encouraged future researchers to engage in more long-term studies into IF’s impact on obesity and weight. (8)

There are so many benefits to intermittent fasting besides weight loss, but managing a healthy weight is indeed an IF benefit.

5. Improved Mental Health

Intermittent fasting often directly and indirectly influences mental health and mood disorders like depression. Fasting endorphins are mood-enhancing hormones that IF may release.

A 2023 review concluded that IF benefits mood through the following mechanisms: (9)

• Better metabolism
• Favorable body composition
• Improved gut bacteria balance
• Healthy circadian rhythm
• Neurogenesis
• Increased availability of neurotransmitters

IF has shown a lot of promise in improving stress, anxiety, and depression symptoms, especially when there is some measure of caloric restriction. Multiple reviews have found that IF is safe even for people with diabetes. (10)

Improved mental health is a benefit I hear from my patients and social media followers all the time — I’ve even experienced this benefit in my own life!