The Leangains Method of Intermittent Fasting: Basics, Research & Comparison

Written by: Ioannis Nikitidis, MD, MSc


The Leangains style of intermittent fasting (aka 16/8 fasting method) was created by Martin Berkhan as a way for bodybuilders to build lean muscle mass without unnecessary weight gain from fat. Traditionally, bodybuilders “bulk” during their training period; they build muscle underneath fat. In the weeks leading up to a competition, bodybuilders then “cut” to get rid of excess fat.

Berkhan mapped out the Leangains as a way of showing bodybuilders how to consistently build lean muscle mass—without fat—so that cutting before a competition could be avoided altogether. The Leangains diet has since been used by a variety of fitness enthusiasts looking to trim down and tone up at the same time.


The Science Behind Intermittent Fasting

While Berkhan pioneered the specifics of the Leangains style of intermittent fasting, periodic fasting for health is not a new concept. Fasting forces the body to use fat as fuel instead of glucose. This shift converts fat into ketones; ketones burn more efficiently than glucose which results in more consistent energy levels and fat burn.

A study at Harvard University found that alternate-day fasting among mice, “protected mice from strokes, Alzheimer’s and Parkinson’s disease, and consistently extended their life spans by 30 percent.” So not only are there weight loss benefits to intermittent fasting; there are long term health benefits as well.


The Leangains Research

Contrary to other fat loss methods, the Leangains method is not based on hypothetical or personal opinions, but it is based in scientific research. A number of studies conducted in order to investigate the effects of intermittent fasting and some of them included the Leangains protocol of 16 hours of fasting and 8 hours of feeding.

One of the most recent published studies and easily to access for free, was conducted by Moro and her colleagues and investigated the effects of eight weeks of time-restricted feeding on metabolic factors, body composition, strength and other markers in resistance-trained males.

The study of Moro and her colleagues compared two groups of resistance trained athletes, the one group used the time-restricted feeding while the other group was on a normal diet. The first group (time-restricted feeding) consumed their calories in an 8-h period of time every day, divided into 3 meals: 1 p.m., 4 p.m. and 8 p.m.

The remaining time of the day was the fasting period. The second group (normal diet) consumed their energy needs divided into 3 meals: 8 a.m., 1 p.m., and 8 p.m. Both groups consumed the same amount of calories and % of macronutrients. In addition, they used a standardized resistance training program. Subjects were tested, before and after the 8 weeks of the program, to compare the results between the 2 groups.

According to the results of the study, the fat mass of the time-restricted feeding group decreased significantly (−16.4 versus a reduction of  −2.8 % in the normal diet group). An increase, similar between the 2 groups was observed on Leg press maximal strength. Insulin and blood glucose levels decreased significantly only in the group of males on the time-restricted feeding.

In addition, triglycerides levels decreased only in the time-restricted feeding group. The hormone adiponectine which is related to increased energy expenditure also was higher only in the time-restricted group. However, anabolic hormone levels, such as testosterone were lower after the time-restricted feeding, while in the normal diet group no change was observed.

So the scientific research shows that time-restricted feeding maintains muscle mass, reduces body fat levels and inflammation markers. The mechanism of greater fat loss in time-restricted feeding group compared to the normal diet group seems to be due to the different time of meal distribution. Despite the fact that this study was conducted in resistance trained males, the observation that insulin and blood glucose levels decreased significantly indicates that time-restricted feeding like leangains method could also improve health markers related to patients such as diabetics and obese patients.

Although there is a great number of studies conducted in order to battle obesity and diabetes, very few managed to provide a really effective and useful tool. The leangains method seems to be a promising natural alternative and future studies are expected to strengthen current scientific findings.


The Leangains Method Explained

Berkhan’s Leangains style of intermittent fasting was designed for people who want the benefits of intermittent fasting without compromising their fitness and/or strength training. Whereas other methods of intermittent fasting focus more on the fasting cycle and less on the specifics of what an individual is eating, Leangains emphasises proper pre and post workout nutrition. Berkan also goes in depth to explain calorie cycling, macronutrients and meal times.

Here is a basic breakdown of the Leangains protocol:

There is a 16 hour window for fasting each day. The majority of this time is taken up during sleep. For women this is a 14 hour window as women’s bodies and metabolisms differ from men’s.

There is an 8 hour window for feeding each day. During this time three meals are usually eaten. For women this is a 10 hour window.

Protein intake remains high on all days. On workout days, it is more important to get carbs before fat. On rest days, fat intake tends to be higher. These variables change depending on the gender, age, body fat, activity levels and the goals of an individual.

Workout days start with a medium-sized meal of meat, veggies and fruit. Training is meant to happen within three hours of this first meal. A larger meal can be had post workout.

Rest days involve a lower calorie intake. Carb consumption should be restricted whereas meat and fibrous veggies make up the bulk of the calories eaten on rest days. The first meal of the day is the largest consisting of roughly 40% of the daily calorie intake.

The last meal of the day should involve a slow digesting protein. This maintains a feeling of fullness and ensures that your body has enough amino acids until the next meal to prevent muscle atrophy.

Whole and unprocessed food should be eaten whenever possible. Avoid processed or liquid foods.


Pros and Cons of the Leangains Diet

Like any diet protocol, there are pros and cons to the Leangains plan. As Berkhan designed the Leangains for bodybuilders, it is meant to be used in conjunction with very specific macronutrients and meal times.


The Leangains is an effective way to build lean muscle without having to put on fat. It is also an effective way to lose weight and keep it off.

Unlike other intermittent fasting protocols, Leangains involves eating every day; there are no 24 hour fasting periods. This supports a rigorous training schedule.

Leangains has slightly different protocols for men and women which allows it to be sustained and deliver results for both genders.


As Leangains was designed for bodybuilders, the best results will be seen if the full protocol is followed. This involves taking the right supplements at the right time in relation to workouts as well as very specific meal times and macronutrients.

All the variables involved in executing the Leangains diet mean that it can take time to figure out the specifics of what works for each individual.


Leangains vs. Eat Stop Eat

The Eat Stop Eat style of intermittent fasting is much more simple than Leangains. In the Eat Stop Eat protocol, there are one or two 24 hour fasting periods within a week. These fasts can be done at any point during the week to suit the needs and the schedule of the individual. Just like the Leangains plan, these 24 hour fasting periods force the body to start burning fat at a higher rate.

The Eat Stop Eat plan does not specify the types of foods that need to be consumed. However, there is an emphasis on whole and unprocessed foods along with plenty of lean protein and leafy green vegetables.

Unlike Leangains, Eat Stop Eat requires no special macronutrients or a strict meal schedule. Meals can be eaten at regular times on non-fasting days and no special supplements need to be taken. In this way, it is much easier to start the Eat Stop Eat method. While Leangains was designed specifically to support bodybuilders and fitness enthusiasts during training, Eat Stop Eat was designed to be used by everyone.

It is an easy lifestyle change that can be started right away without any planning or a complete diet overhaul. Leangains is a good option when trying to maintain a rigorous workout schedule while Eat Stop Eat is well suited for sedentary to moderately active people looking to reduce their body fat percentage.

If you want to learn more on how Eat Stop Eat style of intermittent fasting can help you lose weight and improve your health, please CLICK HERE.






1) Berkhan, Martin. “Sure-Fire Fat Loss.” Intermittent Fasting Diet for Fat Loss, Muscle Gain and Health. June 27, 2008. Accessed October 10, 2016.

2) O’Connor, Anahad. “Fasting Diets Are Gaining Acceptance.” The New York Times. March 7, 2016. Accessed October 10, 2016.

3) J Transl Med. 2016 Oct 13;14(1):290. Effects of eight weeks of time-restricted feeding (16/8) on basal metabolism, maximal strength, body composition, inflammation, and cardiovascular risk factors in resistance-trained males. Moro T, Tinsley G, Bianco A, Marcolin G, Pacelli QF, Battaglia G, Palma A, Gentil P, Neri M, Paoli A.

4) Nutr Res. 2016 Jun;36(6):603-11. doi: 10.1016/j.nutres.2016.02.005. Epub 2016 Feb 20. Time-restricted feeding reduces adiposity in mice fed a high-fat diet.
Sundaram S, Yan L.

5) Adipocyte. 2015 Apr 20;4(4):319-24. doi: 10.1080/21623945.2015.1025184. The effects of time-restricted feeding on lipid metabolism and adiposity. Chaix A, Zarrinpar A.


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