The reality of weight loss is that it generally comes down to “calories in versus calories out”. In other words, we need to burn more calories than we consume in a given week if we wish to see the scale drop. While most people realize that, many of us do not want to spend precious time counting every calorie or restricting the types of food we eat.
One tool used for weight loss (as well as other health benefits) that has gained popularity recently is the method of intermittent fasting. Intermittent fasting (IF) is a term used to describe a timed method of eating that involves periods of eating along with periods of fasting (not eating). There are several methods used for IF . In this article, I will describe some of the most common methods and will explain how to do intermittent fasting to lose weight.
While the primary reason for weight loss is the overall net reduction of calories in a week when combining eating with fasting periods, IF also uses our natural circadian rhythm to optimize fat burning and metabolic rate through fasting. Some studies show that IF leads to greater fat loss with a reduction in the amount of muscle lost in subjects who use IF for weight loss compared to those who do diets involving continuous calorie reduction.
Things to Consider Before Fasting
While intermittent fasting is safe and produces many health benefits for most, there may be some medical conditions that would be contraindications for fasting. It is always best to consult a physician before starting any new diet or fasting regimen. Intermittent fasting is never advised for women who are pregnant, nursing, or who have a very low body fat percentage.
Women may respond a bit differently to fasting than men, so it is important to consider and often modify fasting schedules to fit the unique needs specific to being a woman. Prolonged fasting has been shown in some cases to cause changes to menstrual cycles, reproductive systems and bone integrity. This is generally a result of a calorie restriction that is too extreme for too long. This results in hormonal changes that affect a woman’s ovaries. For this reason, women are best suited for modified intermittent fasting methods. Shorter and less frequent fasting cycles may be more beneficial for women as compared to men.
Benefits of Intermittent Fasting
When done safely, intermittent fasting may lead to many health benefits such as:
- weight loss through calorie reduction, reduction in body fat, and increase in metabolic rate
- reduced risk for Type 2 diabetes due to lower blood sugar and lower insulin resistance
- reduction of inflammation and aging processes caused by free-radicals in the body
- reduced risk of heart disease by impacting blood pressure, cholesterol and triglycerides
- possible reduced risk of cancer, though only shown in animal studies thus far
- improved brain health
For the purposes of this article, we are going to focus on some of the most common methods for intermittent fasting. While we will discuss several, it is important to note that it is best to stick with one method for at least a month before switching to another. When choosing which method is right for you, it is important to consider what your goals are, what best matches your lifestyle, and what you are most likely to stick to.
When deciding on a method, keep in mind that you do not need to eat a certain type of food. You can eat what you want to eat. However, to reach weight loss goals, it is a good idea to follow a diet made up of lean protein, healthy fats, and high fiber fruits and vegetables during the eating periods. Weight loss results may otherwise be compromised by a diet that is high in simple carbohydrates and calories. It is also VERY important to drink plenty of water during the fasting and feasting periods.
Methods of Intermittent Fasting
1. Eat Stop Eat
Eat-Stop-Eat is an intermittent fasting method introduced by Brad Pilon, weight loss expert. It is also referred to as the 24 hour plan. Because the fasting period is quite long, this method may not be the most ideal for women and people new to IF. While it may be fairly difficult for many people to jump right into this method, the rules are fairly simple:
- Stop eating for a period of 24 hours (Never longer). If you can’t make 24 hours, you may do 20 instead
- Do this 1 to 2 times per week (Never more than twice per week)
- Never fast on consecutive days
- Have several days of normal eating between fasting days
- Aim for about 2,000 calories on the eating days
- Drink water, tea, coffee, diet soda, or sparkling water on fasting days
- Try to get 20-30 grams of high quality protein every 4-5 hours on the non-fasting days
- If gaining weight or not losing, try to reduce food intake by 10%
The Warrior Diet
The Warrior Diet is one of the most extreme intermittent fasting methods, and may not be the best option for beginners. Also, with the unique ways in which women’s bodies respond to longer periods of fasting, it is not highly recommended for women. For those who wish to try it, the rules are pretty simple. For every 24 hour day:
- Eat most of your daily food intake in a 4 hour period
- Fast for the remaining 20 hours (consume very little other than water or other calorie free beverages)
The 5:2 Diet, or Alternate Day Fasting
The 5:2 is a more moderate approach to intermittent fasting. It involves consuming a smaller amount of calories two days out of the week. The basic method is as follows:
- 5 eating/non-fasting days per week
- On non-fasting days, eat a normal amount of food, consistent with your basal metabolic rate.
- 2, non-consecutive, fasting days per week
- On fasting days, only consume 500-600 calories
- Can be further modified to add a 3rd fasting day, thus alternating every other day fasting with non-fasting days
Leangains or 16/8 method
Leangains is an intermittent fasting method introduced for weight lifters by Martin Berkhan, but has become very popular with others just interested in the health and weight loss benefits of IF. It is an intermittent fasting cycle that requires shorter periods of fasting than some of the more extreme methods. How it works:
- Men doing this method will eat for 8 hours, and fast for 16 hours
- Women should modify the eating period to 10 hours, fasting for 14 hours
- Women may eventually move to the 16/8 cycle of fasting/eating if tolerating 14/10 and if no adverse side effects
- During fasting period, no food should be eaten
- Unlimited calorie-free beverages are allowed during the fasting period
The Crescendo Method
The crescendo method is another fasting method that is well suited for women. How it works:
- Fasting is done every other day, such as Monday, Wednesday, Friday
- Women should eat for 10 hours, fast for 14 hours on the designated fasting days
- Eat normally on non-fasting days
- after several weeks, you can add another fasting day or increase the fasting window by 1 hour (thus the name crescendo)
Fasting for Fat Loss
We have discussed several options for how to do intermittent fasting to lose weight. IF combines calorie reduction with optimization of fat burning by increasing metabolic rate during fasting periods. Intermittent fasting can lead to many other health benefits as well. It may reduce risk factors related to heart disease, diabetes, cancer, and brain health.
There are several methods for intermittent fasting, though some of the more moderate approaches (Leangains, 5:2, or crescendo) may be better suited for the unique needs of women. Whether you choose fasting or other methods of weight loss, the most important things to look for are plans that you can stick to, fit within your lifestyle, are safe, effective and promote a more healthy lifestyle long term.