The Practicality and Sustainability of Flexible Dieting

17 Feb



Take a look at some of the popular diets being promoted via social media, fitness magazines, and celebrities. Chances are you will quickly become lost and increasingly confused. With so much nutrition dogma promoted in the fitness community, no wonder individuals may find it difficult to find the truth in goal-oriented nutrition practices.

If you are reading this, chances are you are contemplating taking a dive into the world of health and fitness or have already taken the plunge to improve your health and body composition. At some point or another, you have most likely made an attempt to determine the most appropriate nutrition protocol for meeting your goals.

Fad diets

First off, let’s address fad diets. Fad diets are diets that promote quick weight loss and restrict or eliminate specific macronutrient s or food groups completely. The problem with most fad diets is they are not sustainable overtime. Yes, you may lose weight on a fad diet. However, did you learn the art of balancing caloric intake in relation to your body’s metabolic needs and your body composition goals?

Fad diets may work temporarily in terms of weight loss because they eliminate food groups completely which is an indirect way of decreasing overall caloric intake. The opportunity for growth and development in terms of building a sound nutrition knowledge-base by learning to become an educated nutrition consumer is severely restricted when fad diets are used for weight loss. With that being said, fad diets are forever fleeting.

Shortcomings of cookie-cutter nutrition plans

What about cookie-cutter diets you read in your favorite fitness magazines? You know, the diet plans your favorite fitness or bodybuilding competitors reportedly follow. Most of these diets focus on the specific foods you eat at each meal – rather than the overarching determining factor that should drive your goals– overall caloric intake. There is nothing inherently magical about 6-8 small meals consisting of the same monotonous food items.

Furthermore, most of these plans fail to break down the calories and macronutrient profile for the diet as a whole. An individual’s nutrition protocol should be individualized based on height, age, activity level, goals, and current body composition. Failing to construct a nutrition plan without taking these variables into consideration leaves the individual shooting in the dark. What if progress stalls?

How can you accurately adjust macronutrients and calories accurately if you had no idea how much you were eating to begin with?

Introducing: Flexible dieting

Flexible dieting, also known as IIFYM (If It Fits Your Macros), has surfaced as a nutrition approach that accommodates the basic rule of physics in terms of energy balance: thermodynamics. The premise of IIFYM is the belief that the individual has a set macronutrient target that should be hit every day to achieve fitness goals.

What is a macro-nutrient?

Macro-nutrients are nutrients that yield energy in the form of calories. The three macronutrients include:

  • Carbohydrate
  • Protein
  • Fat

What is a micro-nutrient?

Macronutrients are needed in larger amounts for energy metabolism purposes, while micronutrients are only needed in small amounts within the diet. Micronutrients include:

  • ·         Vitamins
  • ·         Minerals

The big picture

IIFYM is a very flexible nutrition approach in which arbitrary food labels such as “bad foods” and “clean foods” are disregarded. We have all heard someone say they “eat clean” when trying to lean up, but what exactly constitutes a food as being a “clean” food? And isn’t the total calorie intake more important for dictating body composition changes than a subjective label of a “clean” vs “dirty” food? 

Can our bodies decipher between a “clean food” and “bad food” when digesting and absorbing nutrient substrates at the molecular level? At the cellular level, the body recognizes food parts as glucose, amino acids, and lipids.

Research has suggested the effect of meal frequency on metabolism does not lead to a greater fat oxidation (Munsters 2012). Dogma of stoking the metabolic fire by eating every 2 hours to reap the “thermogenic effect of food” is often promoted by “fitness gurus,” however, research (Taylor 2001) suggests otherwise. From a thermodynamics standpoint, total energy intake (calories) in relation to calories burned is the driving force in dictating energy balance.  

For instance, a trained individual counting macronutrients with a consistent caloric intake of 3,200 calories in four meals is no different than that same individual consuming 3,200 calories via eight meals.

With that being said, subjectively obsessing over a specific food rather than taking an aerial view of the bigger picture is neglecting the overarching determinant – total calorie intake. We sometimes fail to look at the parts and not the whole. The purpose of IIFYM is to focus on achieving daily set macronutrient targets (fats, carbohydrates, protein), and also micronutrient goals (vitamins and minerals) in an effort to achieve your desired body composition.

The problems with IIFYM dieters is too often individuals will hit their macronutrient targets while coming up short in terms of achieving an adequate intake of vitamins and minerals. It is the thought of the author that the bulk of one’s diet should focus on nutrient-dense foods for a number of reasons:

1)      To meet fiber recommendations (25-38g per day or 14g fiber per 1000 kcals)
2)      To obtain phytonutrients via the diet – which may possess anti-cancer benefits while possibly preventing the onset of some chronic diseases
3)      To acquire sufficient micronutrients including vitamins and minerals
4)      To promote sustainability in terms of life-long dietary habits

Is Flexible Dieting Sustainable?

If body composition improvement is the primary goal, consistently hitting one’s target calorie and macronutrient numbers is by far the single most significant step to achieving one’s desired body composition goal – whether  it be fat loss or building lean body mass.

There is a learning curve with counting macronutrients and becoming accountable for tracking calorie intake. The educational process of becoming an informed consumer in terms of monitoring nutrition intake and reading food labels is the beauty of flexible dieting. In doing so, one learns the art of balancing macronutrients to achieve a desired outcome.

Through monitoring intake, one can adjust and refine the numbers accordingly to achieve the desired body composition goal. If one is not aware of how many calories or what distribution of macronutrients he or she is consuming, how can that person optimally manipulate and adjust energy needs once progress stalls if he or she had no clue what their energy intake looked like in the first place?

The sustainability of flexible dieting is applicable if the individual takes ownership in becoming an educated consumer. Establishing a sound knowledge-base of logging total calories and learning the art of balancing macronutrients based on estimated calorie needs in relation to body composition goal is paramount.

Familiarizing oneself with macro and micronutrient content in relation to serving size is also very important. It is always beneficial to use a food scale, measuring cups, or measuring spoons to recondition ourselves on what a true “serving size” is. The ultimate goal of flexible dieting is to instill learned behavior of what a serving size of particular food looks like to where the individual can “eyeball” a particular serving size of a food without measuring while being rather precise and accurate.

In terms of physiological processes behind physique transformation, total energy intake is the driving force in determining body composition. With keeping nutrient-density in mind, one can achieve a desired body composition goal while enjoying a variety of foods. Honoring personal preference is one of the most powerful, yet underrated tactics for achieving optimal health and body composition. The art of flexible dieting serves as an educational tool for the individual, promotes balance, and instills a nutrition-centered mindset for the individual based on longevity and sustainability.


1.      Marjet J. M. Munsters, Wim H. M. Saris. Effects of Meal Frequency on Metabolic Profiles and Substrate Partitioning in Lean Healthy Males. PLoS One. 2012; 7(6): e38632. Published online 2012 June 13. doi: 10.1371/journal.pone.0038632


2.      Taylor, J. S. Garrow. Compared with nibbling, neither gorging nora morning fast affect short-term energy balance in obese patients in a chamber calorimeter. Int J Obes Relat Metab Disord. 2001 April; 25(4): 519–528.


11 Responses to “The Practicality and Sustainability of Flexible Dieting”

  1. Jen February 17, 2014 at 4:27 pm #

    This is too true and you explain the concept concisely and articulately, bravo! I spent far too long looking for the ‘best diet’, eliminating food groups and following cookie cutter plans. Much happier now I can eat the odd packet of malteasers and have cereal at night without labeling these things as ‘bad’!!

  2. Rick De Camp February 17, 2014 at 10:35 pm #

    Very good information for any person concerned with smart eating. I’m a 63 year old bodybuilder and after all these years in the gym and trying to eat to grow and maintain my gains – this will go in my book of EATING SMART!!. Thanks

    • Cornerstone Training & Nutrition February 18, 2014 at 5:54 pm #

      Thanks for reading the article Rick…. Very inspiring to us to see a 63 year old bodybuilder taking care of his health and physique. We really appreciate the comment.

  3. Chris Marzarella February 18, 2014 at 1:33 pm #

    Fantastic article and very similar to how I teach my clients how to diet and live. I’m a big believer in this methodology.

    • Cornerstone Training & Nutrition February 18, 2014 at 5:56 pm #

      Thanks Chris…. Our clients are often surprised when we explain the principles and for them to know that they can have certain foods that is termed as “bad” gives them the power to sustain and maintain the success that they work hard for. I am sure your clients have had great success under your guidance. Thanks for taking the time to comment!

  4. Fred Carico February 19, 2014 at 5:06 pm #

    Good read I have lost 17 lbs. since Christmas. Will be using a lot of the flexible

  5. Jaqui Dee February 25, 2014 at 8:22 am #

    Just for interest sake… How do you determine the daily calorie need of people?
    With my clients I work on 14 cal per Lean Pound.

    • Cornerstone Training & Nutrition February 27, 2014 at 2:39 pm #

      Hi Jaqui,

      Thanks for the comment. For estimating energy needs, Mifflin St-Jeor x an individualized activity factor with special consideration of goals, metabolic capacity, and current body composition.

  6. Shayna June 27, 2014 at 12:03 am #

    magnificent publish, very informative. I ponder why the other experts of this sector don’t notice this.
    You must proceed your writing. I am confident, you have a huge readers’ base already!

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

%d bloggers like this: