It increased good HDL cholesterol and decreased both bad LDL cholesterol and triglyceride levels. One animal study in the Journal of Nutritional Biochemistry showed that intermittent fasting caused an increase in levels of adiponectin, a protein involved in the metabolism of fat and sugar that may be protective against cardiovascular disease and heart attacks.

In fact, in one study, rats that fasted every other day were nearly 66 percent more likely to survive a heart attack than those on a normal diet.

Inflammation is a normal immune response to injury. Chronic inflammation, on the other hand, can lead to chronic disease. Some research has even linked inflammation to conditions like arteriosclerosis, diabetes, obesity and cancer.

A study published in Nutrition Research followed 50 individuals observing Ramadan and showed that they had decreased levels of some inflammatory markers during Ramadan fasting.

Another study in discovered that a longer duration of nighttime fasting was associated with a decrease in markers of inflammation. In the journal Rejuvenation Research , alternate-day fasting helped reduce markers of oxidative stress. While more research is needed, these studies provide promising evidence showing that intermittent fasting may help reduce inflammation and fight off chronic disease.

In addition to keeping your heart healthy and warding off disease, some studies have indicated that intermittent fasting protects the health of your brain.

One animal study showed that intermittent fasting helps enhance cognitive function and protect against changes in memory and learning function compared to a control group. Another animal study found that it protects the brains of mice by influencing certain proteins involved in brain aging.

Because leptin is produced in the fat cells, those who are overweight or obese tend to have higher amounts of leptin circulating in the body. However, too much leptin floating around can cause leptin resistance, which makes it harder for it to effectively turn off hunger cues. One study with 80 participants measured leptin levels during intermittent fasting and found that levels were lower at night during the fasting period.

Lower levels of leptin could translate to less leptin resistance, less hunger and potentially even more weight loss. Related: Reverse Dieting: Does It Help or Hurt Weight Loss? As described above, there are many types of intermittent fasting with different options that can fit any schedule or lifestyle.

This typically just involves skipping your evening snack after dinner and skipping breakfast the next morning as well. and 12 p. If 16 hours of fasting feels too daunting at first, begin with a shorter fast lasting about 13 to 14 hours. Increase how long you fast as your body gets accustomed to it.

Otherwise, you risk slowing down your metabolism, which is the opposite of what you want. Keep in mind that intermittent fasting should be viewed as a change in lifestyle rather than a diet.

Be sure to focus on filling your diet with healthy whole foods during the days that you do eat to squeeze as many nutrients as possible into your day. Stricter forms of fasting, such as going an entire day without food, require more precautions. Why might intermittent fasting be bad for some people?

If you suffer from low blood sugar, for example, going without eating all day may lead to dangerous side effects due to a drop in blood sugar causing symptoms like shakiness, heart palpitations and fatigue.

If you have a history of eating disorders, this is also not a good tool for you as it may encourage unhealthy behaviors and trigger symptoms. If you are a child or teenager and still growing, intermittent fasting is not recommended either.

Among those who have gallstone disease, fasting may actually increase the risk of gallbladder problems and should be avoided. Finally, studies show that fasting may alter levels of your thyroid hormones. If you suffer from any thyroid issues, you may want to reconsider intermittent fasting to avoid alterations in these important hormones.

Those who are sick may also want to reconsider fasting as it can deprive your body of the steady stream of nutrients that it needs to heal and get better. Is intermittent fasting safe for women? Certain women may encounter hormone issues if they fast for days on end — they may benefit from doing intermittent fasting only a few days a week rather than every day, for example.

Those who are pregnant and breastfeeding should also avoid fasting and focus instead on a nutritious diet rich in vitamins and minerals. Popular Nutrition Posts All Time This Week {position} Detox Your Liver: A 6-Step Liver Cleanse. More Nutrition Dr. Axe on Facebook 82 Dr. Axe on Twitter 4 Dr.

Axe on Instagram Dr. Axe on Google Plus Dr. Axe on Youtube Dr. Axe on Pintrest 68 Share on Email Print Article ANSWER: One diet trend that shows no sign of going away soon is intermittent fasting. That's when you voluntarily abstain from food or beverages other than water for a certain amount of time.

Some fasting is for religious reasons, while others fast for weight loss. Recent research has found that using intermittent fasting for weight loss may have some benefits in the short term. It appears that fasting for a short time can produce ketosis, which is a process that occurs when the body doesn't have enough glucose for energy, so it breaks down stored fat instead.

This causes an increase in substances called ketones. This, coupled with fewer calories consumed overall, can lead to weight loss. Research suggests that alternate-day fasting is about as effective as a typical low-calorie diet for weight loss.

Fasting also affects metabolic processes in the body that may work to decrease inflammation, as well as improve blood sugar regulation and physical stress response. Some research shows this may improve conditions associated with inflammation like arthritis, asthma and multiple sclerosis.

Little long-term research has been conducted on intermittent fasting to examine how it affects people over time. As a result, long-term health benefits or risks are unknown. Intermittent fasting can have unpleasant side effects, like hunger, fatigue, insomnia, irritability, decreased concentration, nausea, constipation and headaches.

Most side effects go away within a month. Sticking with an intermittent fasting routine can be easier for some people rather than trying to watch calories every day. Other people, especially those with busy or variable schedules, have more difficulty maintaining an intermittent fasting routine.

Intermittent fasting is safe for many people, but it's not for everyone. Skipping meals is not recommended for people under 18, those with a history of disordered eating, or those who are pregnant or breastfeeding.

Athletes may find it difficult to fuel and refuel appropriately for an active lifestyle. If you have diabetes or other medical issues, it is important that you talk with your health care team before starting any type of fasting regimen. Also, note that the key to achieving weight loss with intermittent fasting is not to overeat during your eating windows.

As with any weight loss plan, eating fewer calories than you expend remains the basis for losing weight. Also, keep in mind that shortening your eating window may make it difficult to get the necessary vitamins and minerals your body needs. While on an intermittent fasting diet, it is important to eat nutritional meals made from quality, healthy ingredients, such as fruits, vegetables, whole grains, low-fat dairy and lean protein.

for three months didn't lose more weight than those who followed a more typical eating pattern, including eating a big meal after 5 p. Nisa Maruthur, lead author of the AHA research and associate professor of medicine at Johns Hopkins University in Baltimore, previously told TODAY.

The timing of meals was less important than the amount of food a person ate, they noted. It may protect the heart by controlling inflammation, according to the American Heart Association.

it's better because it allows your body to do this metabolic catch-up during a fasting state when you're not eating," Dr. Susan Cheng, a professor of cardiology and the director of public health research in the Smidt Heart Institute at Cedars-Sinai in Los Angeles, told TODAY. Studies and clinical trials suggest intermittent fasting has "broad-spectrum benefits" for health problems including obesity, diabetes, heart disease, cancer and neurologic disorders, according to a review of research in humans and animals published in in The New England Journal of Medicine.

The powerful health effects appear to come from the body shifting away from using sugar as its main source of energy and instead converting fat for fuel when a person's stomach is empty.

But most people still eat throughout the day and miss out on the health benefits of a fasting window, said the review's lead author, Mark Mattson , Ph. Eating only within an eight-hour window can help people with Type 2 diabetes lose weight and manage their blood sugar, according to a study published in JAMA Network Open in October The clinical trial involved 75 adults with Type 2 diabetes and obesity who were randomly divided into three groups for six months.

One group could eat whatever and how much they wanted but only between noon and 8 p. The participants' weight and blood sugar levels were measured at baseline, and then regularly throughout the six-month trial. HbA1c measures a person's average blood sugar levels over the past three months. It fell about 0.

The fasting group also lost about 10 pounds over six months on average, compared to less than 6 pounds for the calorie-counting group. Eating fewer calories is commonly prescribed as the first line of defense in Type 2 diabetes treatment, but many patients struggle with it so time-restricted eating may offer a "refreshing alternative," the paper noted.

There were no serious adverse events reported during the trial, so the study shows intermittent fasting is safe in this population group, Varady said. But she advised people with diabetes to always check with their doctors before starting time-restricted eating. The findings need to be confirmed by larger trials with longer follow-up, the authors noted.

Intermittent fasting isn't for people with Type 1 diabetes who take insulin because it may result in unsafe levels of hypoglycemia, or low blood sugar, during the fasting period, Mattson said.

It also reconnects people with true, biological hunger and makes it easier to recognize fullness, so they stop eating sooner, Fernstrom noted. She's the co-author of a review of studies that found intermittent fasting is generally safe and produces few gastrointestinal, neurological, hormonal or metabolic adverse effects.

Varady dabbles with intermittent fasting herself, typically for a few weeks after the holidays to lose a few pounds.

If you're ready to try intermittent fasting, Varady has some tips to make sure you do it in a way that is healthy and works with your life. Experts advise picking an eating window that lets you finish your meals fairly early, such as 10 a. or earlier, because the body is less efficient at processing sugar as the day goes by.

In an "absolute ideal world," people would eat breakfast, take in most of their calories during the first part of the day, have a very light dinner — if any at all — and then fast for the rest of the evening, Cheng said.

But she noted that many people derive a psychological benefit from sitting around the table at dinner. So it's important to pick a window of time that works for your schedule. If you're a very early riser, for example, it may be difficult to wait until noon to eat.

That's why it's important to exercise before you eat. Fasting for 16 hours may sound tough, but if you're getting the recommended seven or more hours of sleep per night, you'll be asleep for about half of it. Many people are used to grazing and nibbling all day long, but there's no snacking during the fasting periods of intermittent fasting.

Here are some ways to avoid getting "hangry":. Don't drink any alcohol during a fasting window or a fasting day since it's high in calories and has no nutritional value, Varady advised.

During the 4-hour eating phase, people should make sure that they consume plenty of vegetables, proteins, and healthy fats. They should also include some carbohydrates. Although it is possible to eat some foods during the fasting period, it can be challenging to stick to strict guidelines on when and what to eat in the long term.

Also, some people have trouble eating such a large meal so close to bedtime. There is also a risk that people on this diet will not eat enough nutrients, such as fiber.

This can increase the risk of cancer and have an adverse effect on digestive and immune health. The following tips may help people stay on track and maximize the benefits of intermittent fasting:. People who are starting intermittent fasting for the first time may find the 12 hour fasting method the easiest.

This involves fasting for 12 hours every hours period. People can include time when they are asleep in this fasting window, for example, fasting from 7 p.

The amount of weight someone can lose with intermittent fasting depends on various factors, including the type and duration of fasting, their current weight, and how many calories they consume when they are not fasting. The effectiveness of different fasting methods may vary between people.

Fasting for 16 hours may be effective for people who did not see results when fasting for 12 hours. Some fasting practices may involve fasting for one day a week, every other day, or two days a week. People should speak with a healthcare professional to ensure they are staying safe when fasting.

There are many ways to do intermittent fasting, and there is no single plan that will work for everyone. Individuals will experience the best results if they try out the various styles to see what suits their lifestyles and preferences. Regardless of the type of intermittent fasting, fasting for extended periods when the body is unprepared can be problematic.

These forms of dieting may not be suitable for everyone. If a person is prone to disordered eating, these approaches may exacerbate their unhealthy relationship with food. People with health conditions, including diabetes, should speak with a doctor before attempting any form of fasting.

For the best results, it is essential to eat a healthful and balanced diet on non-fasting days. If necessary, a person can seek professional help to personalize an intermittent fasting plan and avoid pitfalls.

People should reach out to a registered dietitian to help them choose the best intermediate fasting that fits their lifestyle. Read the article in Spanish.

Intermittent fasting is a diet plan that means consuming few to no calories on fasting day and eating normally on nonfasting days.

We look at the…. Intermittent fasting has many potential benefits. Tips to start include having a goal and choosing a suitable method. A new clinical trial shows that time-restricted eating, also known as intermittent fasting, helps relieve symptoms of metabolic syndrome.

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