Benefits of Intermittent Fasting for Visceral Fat, Longevity, and Metabolic Health

Intermittent fasting has become a popular dietary buzzword over the last decade, but it’s far from being a new concept. In prehistoric times, fasting was just a part of daily life. As hunters and gatherers, our ancestors often went long stretches without food between successful hunts. We’ve come a long way since then to discover the true scientific benefits of intermittent fasting.

The documented benefits of intermittent fasting as a dietary method also stretch back centuries. In the 1500s, nobleman Luigi Cornaro, made significant changes to his diet and lifestyle habits in his 40s to strengthen his “weak constitution.” He eventually lived to be 103 years old, a shock to his colleagues. Twenty years before his death, he chronicled his dietary changes for posterity.

Today, intermittent fasting is supported by extensive clinical research. In 2019, the New England Journal of Medicine published a landmark peer-reviewed paper on its health benefits. For many, intermittent fasting is more than a tool for weight loss. It’s also a viable approach to living longer, healthier lives.

What is Intermittent Fasting and Why Does It Work?

The human body operates with one goal in mind: survival. If you go 8-12 hours without food, your entire body is out of its primary energy source. You have no more stored glycogen, which provides energy. Your liver and muscle cells are empty, and your brain is screaming for sustenance. As a result, your body begins burning fat for energy instead. Specifically, it targets visceral fat, or the fat that surrounds our organs.

It’s important to note that not all fat stored in the body is “bad.” Humans need certain types of fat to promote healthy metabolism and optimal hormone levels.

However, visceral fat doesn’t hold those positive connotations. High visceral fat levels are linked to conditions like:

• Diabetes
• Heart disease
• Stroke
• Arterial disease
• Certain types of cancers

By prompting the body to burn visceral fat, intermittent fasting may help reduce the risk of these conditions while also supporting metabolic health.

Scientific Benefits: Longevity, Inflammation Reduction and More

The research on intermittent fasting reveals its impact beyond weight loss. Additional benefits include improvements to:

• Thinking and memory
• Blood pressure
• Physical performance
• Type 2 diabetes
• Sleep apnea

Intermittent fasting may also have protective effects against certain cancers and promote longevity. One study reveals that 13 hours without ingesting calories reduces breast cancer recurrence. In laboratory rodents, intermittent fasting improved longevity by 15-20 percent.

Inflammation reduction is another benefit. Chronic inflammation plays a role in the development many serious conditions, such as:

• Alzheimer’s disease
• Arthritis
• Asthma
• Multiple sclerosis
• Stroke

 

The Easiest Diet? Real-life Benefits of Time-Restricted Eating

Aside from the health benefits, one of the best aspects of intermittent fasting is that it doesn’t require people to invest any extra time or money. It doesn’t require special foods, hours measuring and weighing your meals, or calorie counting. There are also no “off-limit” foods. You can still enjoy your favorite meals and snacks as long as you do so in moderation.

In truth, all intermittent fasting really takes is time. You already fast every night while sleeping, right?

A popular intermittent fasting schedule is 16:8, or fasting for 16 hours and feasting for eight. Your goal should be to fast for at least 13 hours a day, which is where the measurable health benefits take hold. However, there’s no detriment to switching up your schedule. Some days you may hit 13 hours, other days, you might aim for 16 or 18.

Consistently practicing intermittent fasting is more important than perception. You might fast for 16 hours on weekdays, then relax your schedule on weekends.  This flexibility makes intermittent fasting easier to stick with long term.

That said, there is some risk in fasting for too long. For example, if you’re regularly hitting the 20-hour mark, you’ll likely start to lose muscle mass. The body can only absorb 30 grams of protein at a time. With a limited feast window, you may not be getting adequate protein intake.

Popular Fasting Schedules: 16:8, 5:2 and Alternate Day Plans

There are multiple different approaches to intermittent fasting. Some of the most common include:

• Time-Restricted Fasting. This approach works by limiting the daily window of feasting. For example, if you eat your first meal of the day at 10 a.m. and your last meal at 6 p.m., you’ve followed the 16:8 plan. Common ratios for time-restricted fasting include 14:10, 16:8, and 18:6.
• 5:2 fasting. In this strategy, individuals eat “normally” five days a week and fast for two days. On the fasting days, they restrict their calorie intake to one 500-calorie meal for women and one 600-calorie meal for men.
• Alternate Day Fasting. Using the same calorie intake as 5:2, fasting takes place every other day.

Time-restricted fasting is usually the best place to start, because you can ease into it by gradually shrinking your feast window. As you get more accustomed to fasting, you might venture into other methods to see if they work for you.

Intermittent Fasting Side Effects and Safety Considerations

Intermittent fasting is generally safe, but it isn’t for everyone. You should consult your doctor before changing your diet plan, especially if you live with one of these conditions:

• Diabetes. Diabetics should consult with their endocrinologist or diabetes educator before starting intermittent fasting. However, for people with insulin resistance, intermittent fasting may prevent diabetes from developing.
• Digestive issues. Some people experience constipation, which can occur especially if they don’t drink adequate amounts of water or eat enough high-fiber foods.

Of course, in the initial stages, one might experience some fatigue, hunger pangs, and possibly headaches. As with any lifestyle change, it takes persistence and time to adapt. Still, it’s critical to have a conversation with your healthcare provider if you’re curious about intermittent fasting’s effects.

Explore Nutrition Coaching and Health Support at Aviv Clinics

Intermittent fasting is a well-researched, low-effort approach to supporting physical health, cognitive performance, and longevity. Whether you’re aiming to lose weight, sharpen your mind, or reduce your risk of chronic disease, it’s a powerful tool—and it costs nothing to start.

At Aviv Clinics, nutrition coaching is one component of the personalized Aviv Medical Program. Our program incorporates physician-prescribed interventions, including a unique, evidence-based hyperbaric oxygen therapy protocol, to help you reach your health goals.

If you’re interested in exploring how Aviv Clinics can support your healthy living goals, we’re here to help.

 

Last Update: July 15, 2025.