June 27, 2019

Could a Type of Intermittent Fasting Improve Your Heart Health?

'Early time-restricted feeding' can produce health + weight-loss benefits

clock with food as numbers

No matter why you’re trying to lose weight, adjusting the timing of your meals may help. In fact, changing the hours you eat may be just as important as the foods you eat or pass up.

Advertisement

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy

Eating only during the first eight to 10 hours of the day — a form of intermittent fasting known as “early time-restricted feeding”— makes your body more sensitive to insulin. If you have prediabetes or borderline high blood pressure, your blood sugar levels and blood pressure will normalize.

Eating by the clock

This eating pattern works because it is in sync with our internal clock (circadian rhythm). Our digestive system is programmed from birth to eat during the day and rest at night when we sleep.

Eating at night requires our bodies to continue producing insulin during the hours we do not require much sugar for energy. As a result, more sugar gets stored as fat. This is why eating at night increases the risk of diabetes and obesity.

“Eating for only eight hours early in the day allows your pancreas to take a break. This improves your metabolism. You will store fewer calories as fat and burn the fat you have,” dietitian Kate Patton, MEd, RD, CSSD, LD, explains.

Why this fasting pattern works

Our bodies break down simple carbohydrates into sugar, which is released into the bloodstream. We need sugar for energy, but when we have overweight or obesity, any excess sugar we don’t utilize to meet immediate energy needs is stored in cells as fat. Insulin produced in the pancreas facilitates the storage process.

When we don’t eat for a period of time, insulin isn’t needed, and our blood insulin levels drop. This signals our fat cells to release sugar to be used as energy. When insulin levels drop far enough, we burn enough fat to lose weight.

Early eating works best

Several intermittent fasting patterns have been studied. Not all were shown to be equally effective.

Advertisement

Alternate-day fasting did not produce greater weight loss or offer any heart healthy benefits above and beyond those obtained from eating a low-calorie diet.

Studies of time-restricted feeding have shown the early eating pattern (8/16, or eating for eight hours after rising and abstaining for 16 hours) to be more effective than a 12/12 pattern in helping to lower insulin levels and normalize blood pressure in men with prediabetes and prehypertension.

Study participants who followed the 8/16 pattern also found they were not hungry in the evening, which made the eating pattern sustainable over the long term.

Not everyone in these studies lost weight, but none gained weight. “There is some flexibility in the schedule. You can eat from 7 a.m. to 2 p.m. or from 9 a.m. to 5 p.m., depending on when you go to sleep and when you rise. The point is that you eat early in the day, and never before bed,” says Patton.

Should you try early time-restricted feeding?

Early time-restricted feeding is a new enough concept that its impact over the long term is unknown. It is thought to be appropriate for most people who could benefit from losing a few pounds, particularly if they are at risk for diabetes.

The diet may not be safe for people with type 1 diabetes, who do not make insulin. “This eating pattern could cause your blood sugar levels to go dangerously high or low,” says Patton.

People taking diabetes medication, people who are pregnant or breastfeeding and anyone with an eating disorder should consult their physician before trying this eating pattern.

Advertisement

What you eat still matters

As is true with any diet, the best results are obtained by combining early time-restricted feeding with healthy food choices.

“You have to eat well. You won’t lose weight if you are eating poorly,” says Patton. “A plant-based or Mediterranean-style diet is ideal. Such diets emphasize fruits, vegetables, lentils, whole grains and healthy fats and restrict the intake of refined grains and sugars,” she explains.

“If you stay active, follow a healthy diet and avoid mindless snacking, restricting the hours you eat will improve your health, and you will likely lose weight, too.”

This article originally appeared in Cleveland Clinic Heart Advisor.

Learn more about our editorial process.

Related Articles

Hand holding glucose measurement device, with bottle of water in background at night
March 15, 2024
Are Religious Fasts Safe for People With Diabetes?

Planning ahead, checking in with your care team and being vigilant about blood sugar monitoring can help ensure a safe fast

person running with food and fitness images floating behind
March 6, 2024
Is It Safe to Work Out While You’re Fasting?

It’s best to exercise before or after your fast, instead of during it

person standing in front of taped off refrigerator thinking about food and watching the time
March 5, 2024
6 Tips for Fasting Safely

Plan ahead by hydrating, cutting back on sugar and managing medications

Place setting with clock as plate separated into eating and non-eating times by clock hands.
July 16, 2023
How Intermittent Fasting Affects Women

Fasting can significantly impact your hormones — proceed with caution

Chicken and beef skewers.
October 11, 2022
What To Know About the Protein-Sparing Modified Fast Diet

This short-term diet is for those who want to lose a significant amount of weight quickly

Closeup of person using a white fork in a to-go container of salad
March 2, 2022
Intermittent Fasting: How It Works and 4 Types Explained

An expert breaks down how and why people try it

woman and newborn baby
September 29, 2020
Can You Do Intermittent Fasting While Breastfeeding?

The short answer from a registered dietitian

Plate indicating intermittent eating and fasting
February 2, 2020
Fasting: How Does It Affect Your Heart and Blood Pressure?

A cardiologist's perspective on pros and cons of fasting

Trending Topics

Person in yellow tshirt and blue jeans relaxing on green couch in living room reading texts on their phone.
Here’s How Many Calories You Naturally Burn in a Day

Your metabolism may torch 1,300 to 2,000 calories daily with no activity

person getting a sinus massage between brows
5 Sinus Massage Techniques To Relieve Pressure and Promote Drainage

A gentle touch in all the right places may help drain your sinuses

woman snacking on raisins and nuts
52 Foods High In Iron

Pump up your iron intake with foods like tuna, tofu and turkey

Ad