6 things you should know about intermittent fasting

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Due largely to the power of social media endorsements, intermittent fasting has become one of the most popular diets in the U.S. But does it work, and is it a healthy strategy for losing weight?

To find out, WellTuned spoke with Melissa Perry, a registered dietitian with BlueCross BlueShield of Tennessee.

“Intermittent fasting is about when you eat, not what you eat. You limit your food intake to specific windows of time—and hope that the pounds come off,” Melissa says. “Its main promise is weight loss, but there are other unproven claims, such as lowering the risk of certain diseases and increasing longevity.”

What you need to know about intermittent fasting

Melissa Perry: Intermittent fasting is supposed to help your body begin burning fat after burning through its stores of sugar. But it’s important to understand how it works and when it’s not appropriate.

1. You pick a time frame in which you will eat food.

A popular approach the 16:8 plan. You eat all your meals (and snacks) during one 8-hour period. You don’t eat anything during the remaining 16 hours of the day. You can drink water, tea and coffee, as long as you don’t add any calories via sweeteners or creamers.

2. It might help you pay closer attention to your eating patterns.

Studies show that any weight loss from intermittent fasting is related to eating fewer calories overall. Many people say it helps them eat fewer calories by avoiding mindless snacking and being more conscious of when they’re eating. However, you might experience hunger pangs and mood swings, especially at the beginning while your body adjusts.

3. There are several different versions of intermittent fasting.

The 16:8 plan is popular, but it’s not the only kind of intermittent fasting. Common kinds of intermittent fasting include:

  • Time-restricted, where you eat only between certain times each day
  • Twice-a-week, where you fast 2 days per week
  • Alternate day fasting, where you fast every other day
  • The 24-hour fast, where you fast one day every week

4. Intermittent fasting is not for everyone.

It’s not safe for some people to try fasting as a way to lose weight, including:

  • Children
  • Pregnant people
  • People at risk for hypoglycemia
  • People with a history of an eating disorder
  • People at risk for an eating disorder

Your doctor may rule out fasting if you have chronic medical conditions, such as diabetes, or take certain medications. You should talk to your doctor before trying any kind of fasting.

5. Intermittent fasting can have other side effects.

Some people may not consume enough calories or eat consistently enough to sustain all the normal functions of their body. This might cause muscle loss and disrupt hormone levels. This is especially important to keep in mind if you exercise regularly and need calories to sustain your activity.

6. Intermittent fasting may raise the risk of cardiovascular death.

Restricting all your food intake to an 8-hour window each day could raise the risk of “cardiovascular mortality.” But it might not be quite as bad as recent headlines warned. Talk to your doctor if you have concerns about how fasting might affect your heart health.

Don’t forget about proven strategies for losing weight

Melissa Perry: Intermittent fasting may appeal to you, but it might not be the best option. You might have more success with a more established approach like the Mediterranean diet.

We have years of evidence showing that eating consistent meals with fruits, vegetables, whole grains, lean proteins and healthy fats helps people lead longer, healthier lives. Intermittent fasting can prevent fueling our bodies in natural, healthy ways. Listening to our body’s natural hunger cues, choosing healthy food and putting food away when we feel full will help us be physically healthy. Listening to our body in this way also helps us have a healthy relationship with food.

More from Melissa Perry on WellTuned

Jennifer Larson

Jennifer Larson is Nashville-based writer and editor with nearly 20 years of experience. She specializes in health care and family issues.

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Get more information about specific health terms, topics and conditions to better manage your health on bcbst.com. BlueCross BlueShield of Tennessee members can access wellness-related discounts on fitness products, gym memberships, healthy eating and more through Blue365®. BCBST members can also find tools and resources to help improve health and well-being by logging into BlueAccess and going to the Managing Your Health tab.