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The Beginner’s Guide to Intermittent Fasting

Intermittent fasting is one of the most popularized health and fitness trends. If intrigued and wondering how to do intermittent fasting, this is what you need to know and how to get started!


Fasting has been practiced for religious and spiritual reasons for thousands of years. However, intermittent fasting (IF) is one of the most popularized health and fitness trends in modern day.

Unlike most advertised diets and weight loss claims, intermittent fasting has a backing of supportive research. The eating pattern shows to improve health and simplify the lifestyles of its respective followers.

The Beginner's Guide to Intermittent Fasting

Intermittent fasting is not exactly a diet, but rather an eating pattern. Instead of focusing on not exactly what to eat, IF places emphasis on when to eat.

Fasting and feasting with intent means consuming calories during a specific window of the day. The remainder of the day is essentially devoid of food, or the "fasting"portion.

The most basic form of fasting is a pattern the majority already does. Fasting between the last meal of the day (generally dinner) and breakfast the next morning (hence "break" the "fast"). More extensively in the health world, fasting periods tend to go for longer bouts of time.

There are seven common types of intermittent fasting, including the following:

1. The 12-Hour Fast: Fast for 12 hours, feast for the remaining 12
2. The 5:2 Plan or Fast Diet:Fast for two days, feast during the other five days of the week
3. Alternate-Day Fasting: Fast every other day, feast the days in between
4. 16:8 or Leangains: Fast for 16 hours of the day, feast the remaining 8-hour window
5. Eat Stop Eat: Fast for 24 hours once or twice per week
6. The Warrior Diet: Fast for about 20 hours each day and feast for the remaining four
7. Spontaneous Meal Skipping: Skip meals spontaneously and randomly

Why Do Intermittent Fasting?

Regardless of the intermittent fasting schedule, there are several claims and evidence-based benefits for the eating plan. And like any diet or new weight loss regimen, seeking out the research is important.

Conclusive, supportive data can help save time and money and decrease the chance of feeling let down. Scientific data and results of intermittent fasting are discussed further.

Intermittent fasting may help with weight loss and maintenance.
Weight loss is a common motivator for one to try intermittent fasting. There are a number of mechanisms that may explain how IF can help shed weight, including the following:

• Caloric deficit: Though weight loss tends to follow a calorie deficit, intermittent fasting does not promote calorie restriction. However, there is often a natural decline in calories when feasting in a short window of time. There is research indicating intermittent fasts plus energy restriction is best for weight loss, too. 

• Stabilized hunger hormones: Weight loss and IF may also be linked to hunger hormone stabilization, particularly leptin and ghrelin. Before meals, ghrelin increases and forms an appetite. Leptin helps create satiety during meal consumption and creates feelings of fullness. The claim is that the body learns how to handle the delay in the hunger response initiated by ghrelin.

Intermittent fasting may lower the risks of chronic diseases.
Intermittent fasting may reduce the risks of or treat a number of chronic and age-related diseases. These include heart disease, cancer, and certain neurodegenerative disorders:

• Heart disease: There is some research indicating intermittent fasting lowers triglycerides more than regular diet. Additional research shows fasting may reduce total cholesterol, LDL, triglycerides and increase HDL levels. Improving these biomarkers can lower the risk of heart disease.

• Cancer: There is ongoing interest in regard to fasting and caloric restriction in cancer prevention and treatment. The UCSF suggests fasting in combination with a plant-based diet may be beneficial for general cancer prevention.

• Neurodegenerative disorders: Intermittent fasting may be useful for successful brain aging and protect against neurodegenerative disorders. These include two of the most common disorders, including Alzheimer's and Parkinson's diseases.

Intermittent fasting may add on precious years of life.
Some of the most profound research of IF is its potential to add on precious years of life. "Intermittent fasting may be center of increasing lifespan," reports the Harvard Gazette.

An animal study demonstrated longer daily fasting times improve health and longevity in mice. The research showed increasing time between meals led to greater overall health and longer lives compared to frequent eating patterns.

How To Do Intermittent Fasting

Whereas pursuing the mode of intermittent fasting is up to the individual, these tips can get prospective followers started:

1. Consult with a Primary Provider
Especially if managing any medical condition or taking medication, consult with a clinician before starting intermittent fasting or any new diet. Meeting with a Registered Dietitian can also help identify personal goals and create a sustainable plan to meet them.

2. Address Worries and Questions
"What if I get hungry?" "Can I exercise in a fasted state?" Address these "what ifs" and questions personally and with a healthcare professional. Doing so helps clear any confusion and smooth the process of following an intermittent fasting eating pattern.

3. Start Slow
"Easy does it" is the name of the game when it comes to intermittent fasting. For instance, rather than jumping in quickly and fasting for a 24-hour stretch, start the process slow. This may include gradually missing breakfast, snacks, etc. Fast for longer bouts as the fasting periods become more comfortable.

4. Be Patient
Especially in the beginning, it is important to not judge the effects in the first day two. This is due to an increased likelihood experiencing brain fog and low energy. At least give the chosen fasting protocol a three-week's shot chance before throwing in the towel. The longer this sort of lifestyle is practiced, the easier and more regimented it will become.

5. Use Time as an Advantage
Rather than fixating on hunger between fasts and feasts, make the most out of time by staying busy. Also, be sure to sleep the recommended seven to nine hours on a nightly basis. Not only is this imperative for overall health, but can help carve out more of the allotted fasted time.

6. Keep Hydrated
Drink plenty of water, as keeping hydrated helps make the fasting periods easier to get through. Black coffee, tea, and other sugar-free drinks are viable options to sip on.

7. Focus on Quality Foods
While intermittent fasting does not necessarily harp on the foods to consume, nutrient-dense foods should be the focus. Nourishing the body with whole grains, fruits and veggies, lean proteins, and healthy fats supports weight loss and overall health.

8. Experiment
Diets and eating patterns are not a one-size-fits-all. And what works for one person, may not work for the next. So experiment and try different strategies that works best for personal goals, needs, and schedules.

Does Intermittent Fasting Work?

Intermittent fasting can be an effective and practical option for people desiring a more simplistic and flexible eating pattern.

Because rather than preparing and eating meals about every two to three hours, there is less to worry about. This includes one less decision to make in the day and less dishes to wash. This grants more time to do focus on work, laundry, and spend time on self-care and with loved ones. See how this college student lost 100 pounds by making these three things top priority: water, sleep and intermittent fasting (which included bistroMD).

However, devoting time to not eating can be a social stressor with happy hours with coworkers and holidays spent with family. What's more, intermittent fasting may affect men and women differently. IF may also not be suitable for people with the following medical conditions and circumstances:

• Diabetes or hypoglycemia (low blood sugar)
• Certain types of medications
• Women who are trying to conceive, pregnant, or breastfeeding
• History or patterns of disordered eating
• Considered to be underweight
• Children and adolescents

It is likewise important to note consuming a copious amount of calories is not recommended. Overeating will likely to lead to weight gain and deter such benefits. A healthy lifestyle incorporates regular exercise, adequate sleep, and stress management.

Ultimately, implementing eating patterns and strategies should work best for personal lifestyles. And like any sort of diet or eating pattern, their success relies on if they can be sustained long-term. Because truly, diets are not often a "one-size-fits-all."

Written By Christy Zagarella, MS, RDN. Published on August 07, 2018. Updated on June 26, 2019.


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