What Is Intermittent Fasting?

When you fast intermittently, you eat within a shortened time window — usually 8-10 hours. For example, you eat your regular dinner and stop eating at 8 p.m. The next day, you skip breakfast and have your first meal at noon. During your fast, you can drink plain water, coffee and tea.

So, why do people fast? Although weight management is definitely one of the benefits of intermittent fasting, it’s not really a diet. It’s an eating schedule that has big payoffs over time, like regulating your insulin levels, protecting against disease and — yup, helping you manage your weight.

This might go against what you’ve heard about eating frequency in the past. Skipping a meal won’t send your body into “starvation mode.” And although there’s nothing wrong with eating breakfast, there are major benefits to giving your body an extended break between meals.

THE SCIENCE OF INTERMITTENT FASTING

When you eat, a lot happens in your body:

  • Depending on what you’ve eaten, your blood glucose (sugar) levels will rise.
  • Your pancreas produces a hormone called insulin.
  • Insulin tells your cells to fuel up on glucose as your gut breaks down your food.
  • Your body releases hormones like cholecystokinin (CCK) and leptin, which signal when you’re full.

However, when you eat a lot of carbs and sugar, ignore your body’s “I’m full!” signals and eat frequently without burning off all that energy, your body struggles to keep up. Your pancreas has to work overtime, and any extra glucose gets stored as fat. Over time, those factors can increase your risk of weight gain, insulin resistance and diseases like diabetes and cancer. Yikes.

That’s one of the many reasons intermittent fasting is so effective: It gives your body time to reset. When you take a break between meals, your glucose levels remain stable, your insulin levels drop and your body has a chance to clean up shop — all of which leads to major benefits like increased energy and brain function.

BENEFITS OF INTERMITTENT FASTING

Weight: Your body preferentially uses glucose (carbs) for energy. When you fast, your body uses up available glucose, and then transitions to burning fat for fuel — which can produce ketones. Plus, intermittent fasting can help prevent insulin resistance and leptin resistance, which may assist with weight management.[1][2][3]

Helps remove cellular waste: Over time, your cells naturally accumulate damaged cells and waste — junk that can interfere with cellular function. Intermittent fasting promotes a process called autophagy, which is what happens when your body clears out the gunk so your body can work even better.[4]

Supports healthy aging: Studies show that intermittent fasting can help protect your cardiovascular system and how you manage blood sugar to support healthy aging. It even helps promote feelings of tranquility and alertness.[5][6][7]

These are just a few notable callouts — turns out, fasting is really good for you on tons of different levels.

Picture of healthy-looking food

HOW TO FAST INTERMITTENTLY

Ready to get started? Great! One of the best parts of intermittent fasting is that it’s really easy to adapt to your daily schedule. You can do it every day, or you can do it just a few times a week. You can even customize the amount of time you spend between meals — which is good news if you have a variable schedule. What matters is that it works for YOU. Check out intermittent fasting apps to help keep you on schedule.

STYLES OF INTERMITTENT FASTING*

5:2:

You eat normally five days a week. On the other two days, you “fast” by eating between 500 and 600 calories.

ONE MEAL A DAY (OMAD):

Also known as eating once a day. You eat all of your daily calories in just one meal each day, and fast the rest of the day.

16:8:

You eat all of your daily calories within a shortened period (typically 6-8 hours) and fast the rest of the time.

*As with any diet or exercise plan, consult your healthcare provider to determine what’s best for you.

SAMPLE INTERMITTENT FASTING SCHEDULE

  • Finish dinner by 8 p.m.
  • Drink a cup of grass-fed butter or ghee coffee in the morning.
  • Eat a high-fat, moderate protein, low-carb lunch at 2 p.m.
  • Finish eating the next day by 8 p.m.

Repeat this schedule every day, or just a few times per week

The biggest takeaway here is that there is no one-size-fits-all approach to intermittent fasting. Take time to find the perfect fit, pay attention to how you feel and don’t be afraid to experiment with different schedules. Check with your doctor before you try intermittent fasting, especially if you’re taking any medications.

SOURCES:

[1] https://www.sciencedirect.com/science/article/pii/S095528630400261X

[2] https://www.ncbi.nlm.nih.gov/pubmed/22289055

[3] https://www.ncbi.nlm.nih.gov/pubmed/20921964

[4] https://www.ncbi.nlm.nih.gov/pubmed/20534972

[5] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3017674/

[6] https://www.sciencedirect.com/science/article/pii/S0092867415001865

[7] https://www.ncbi.nlm.nih.gov/pubmed/23332541

[8] https://bulletproof.com/

 

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