4 Key Principles For Ensuring Successful Body Composition Changes

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Written by Astrid Naranjo (Clean Health Accredited Clinical Dietitian)

For far too many decades, dieters and diet books focused only on bodyweight.  If it went down, that was good. If it didn’t or went up, that was bad. And while body weight is more useful than some think, it doesn’t tell the entire story. Rather, body composition, and altering it, is where the real focus should lie.

Before we dive into today’s topic, if you would like to learn how to create world-leading results with your clients through nutrition programming, click here to enrol into the Performance Nutrition Coach Certification Collection and save up to 70% off with our Cyber Monday sale!

What Is Body Composition?
Body composition refers to everything in the body, split up into different compartments. Two compartments are commonly used: fat mass and fat-free mass (1). Fat mass refers to all the fat tissue in the body. Fat-free mass is everything else, including muscle, organs, bone and fluid.

Now, when it comes to ensuring successful body composition changes, it is generally referred to a decrease in body fat, increase of lean body mass (muscle specifically) or better yet, both.

Most people know that nutrition and exercise can affect body weight as well as body composition. Nonetheless, their impact on body composition isn’t that simple, and most times we need to be more strategic if we want epic body transformations and lasting results when it comes to body composition changes. Your client will lose fat by dieting alone, but not as effectively as they would by using a calorie controlled diet and training program.

What literature has shown that not just works but also makes the process more enjoyable and sustainable is the consideration of these 4 principles:

  1. Don’t let your client lose weight too fast
  2. Cycle your client’s diet & implement diet breaks when needed
  3. Ensure a high protein intake
  4. Encourage resistance training

Let us explain in more detail why we have chosen these 4 principles as the most important and beneficial when it comes to successful body composition changes

1. Don’t let your client lose weight too fast

If your client loses weight too fast, they will inevitably lose muscle mass and ultimately slow down their metabolism (making future weight loss more difficult). It is recommended losing no more than 1% of current bodyweight per week (a slower rate of weight loss is even better!). Example: If your client currently weights 150 pounds, aim for no more than 1.5 pounds per week. If your client’s goal is to lose a total of 20 pounds (to get to 130 pounds), plan on this taking more time! 

It is recommended that you plan on your client’s diet taking at least 14 weeks. If you want to make it potentially more enjoyable for them, and there’s no rush, aim for following the 2nd principle, where you would be implementing some diet breaks and getting your client to lose these 20 pounds over 20 weeks (which would be a loss of about 0.7% of their body weight per week)

Get the point? Encourage your clients no to be in a hurry to lose weight now if it isn’t a life or death situation. Encourage them to take their time. Doing so will cause more of the weight they lose to come from fat stores and will protect muscle mass and metabolism.

2. Cycle your client’s diet & implement diet refeed & diet breaks when needed

The human body isn’t a big fan of dieting. Evolution has taught the body that when calories are restricted, things are not going well and there is food scarcity. So, for the human body it means that it needs to decrease energy expenditure and become more efficient in what it does in order to survive. This makes a lot of sense back when food was scarce and our ancestors were those early humans who were able to evolve this metabolic adaptation to limited food, so they didn’t starve to death. Unfortunately, the human metabolism hasn’t had enough time to unlearn the millions of years of evolution that came before it.

Despite this, all is not lost. Most times it is thought of the term periodization when it comes to training, however, nutrition interventions can also be periodized. Just like it may be useful to change up training, nutrition strategies need to be changed/adjusted at times to elicit the desired response or to mitigate negative adaptation to energy restriction during a fat loss phase. Sometimes this is done mostly for psychological reasons, sometimes this is done for physiological reasons and sometimes for a bit of both. Obviously, the nutrition strategies and interventions should match your client’s evolving goals, rate of fat loss, physical activity levels, etc.

You may have heard that refeeds and diet breaks before, it is actually a bit trendy at the moment since it is quite novel and more research has been coming out in recent years…. Until recently, there wasn’t much research available on the long-term effects of refeeds and diet breaks. Some studies in the early 2000s showed transitory increases in leptin in response to acute overfeeding, however, most of the guidelines around refeeds and diet breaks were based on anecdotal experience. In the last few years, some recent studies looking at the long-term effects of refeeding and diet breaks have helped shed some light on this topic.

Well, these tools can be very handy in terms of teaching or letting the body know to not being so worried about being in a calorie deficit. However, these tools should be used strategically based on your client’s personal circumstances.

Refeeds may be helpful to offset muscle loss and delay the onset of negative metabolic adaptation in the short term. However, it is likely that over time, your client will still encounter some muscle loss and negative metabolic adaptations, especially the longer they remain in a deficit (3-6).

This is where diet breaks come in. A diet break is a planned break from being in a calorie deficit. It’s usually used to break up a longer dieting period and typically lasts a week or two (or longer if needed), returning to eating at maintenance.  In other words, these are periods of time at higher calories that can signal to the body that your metabolism doesn’t need to adapt negatively, because there is some food available.

It makes sense to take intermittent breaks fat loss for a number of reasons (7-10), including:

  • Psychological break from caloric restriction
  • Alleviate some of the water retention issues associated with prolonged periods of fat loss
  • Help bring recovery in from the weight room back up to speed
  • Teaches the client that there is a time and place to “grind”
  • Improve weight loss efficiency by offsetting some of the negative metabolic adaptations

3. Encourage high protein intake

Protein is important for everyone, and your client may need more if they are active or trying to gain muscle or lose fat(11). So this principle is simple:  Don’t decrease protein. If your client doesn’t eat enough protein, they’ll also lose muscle mass, specially in a calorie deficit. The more muscle mass your clients loses, the lower their metabolic rate likely will be.

Also, protein is more satisfying than carbs or fat, and body also burns more calories processing protein than these other nutrients (11,12,16), so why would you want to lower the one nutrient that will fight the most annoying aspect of the dieting—hunger!

Application: Get your client to eat no less than 0.75 grams protein/pound of body weight (1.6 g/kg) when dieting (11,13,18).

4. Encourage and include resistance training in their program

Resistance training helps to preserve muscle mass and metabolic rate when dieting. If your client just dieted, they would end up as a smaller version of themselves and likely risk lean body mass too. Resistance training helps your client building muscle as well as helping them feel good about themselves, and providing a way to destress(17). There are 2 principles you could think of for planning better your client’s training and get the most out of each session: FITT & SOAP (14-15).

The FIIT principle:

  • Frequency: The number of training sessions completed in a given time period(14).
  • Intensity: The level of exertion that your clients are training at (14)—i.e. if you are training for basic strength you will be using 80-90% of your one repetition maximum (15).
  • Time: How long the session lasts for (14)
  • Type: What mode of exercise is being performed (14)—i.e. aerobic, anaerobic, strength, power, etc.

The SOAP principle:

  • Specificity: Training in a specific manner to producing the training adaptation or goal desired (14)
  • Overload: Refers to assigning a workout or training regime of greater intensity than your client is accustomed to. Without the stimulus of overload, even an otherwise well-designed program greatly limits the client’s ability to make improvements(14,15)
  • Adaptation: Training must be continually progressing via overload; otherwise [positive] adaptations can be lost quickly and performance can begin to decline, with fitness and conditioning sometimes returning to its initial state (15)
  • Progression: The intensity of the training must become progressively greater. Progression, when applied properly, promotes long-term training benefits (14,15).


Many people don’t stick with a plan because they get upset with the short-term results (or lack thereof) and completely forget that improving health/fitness and body composition is a lifelong endeavor.

Don’t let your client the process; it will take a concerted effort and consistency on your client’s behalf to achieve the body and level of fitness they desire. If at any point you feel like your client is not making progress, take a step back, assess their long-term goals, and make any necessary changes to their program and current habits to continue their journey.

Focus on making your client’s journey much more efficient, sustainable and enjoyable by following these 4 principles that we discussed.


1.   Müller MJ, Braun W, Pourhassan M, Geisler C, Bosy-Westphal A. Application of standards and models in body composition analysis. Proc Nutr Soc. 2016 May;75(2):181-7. doi: 10.1017/S0029665115004206. Epub 2015 Nov 6. PMID: 26541411.

2.   Wardlaw, G. M. & Hampl, J. S. (2007). Perspectives in nutrition (7th ed.). Mc-Graw Hill: New York, New York, USA.

3.   McArdle, W. D., Katch, F. I. & Katch, V. L. (2007). Exercise physiology: Energy, nutrition, and human performance (6th ed.). USA: Lippincott Williams & Wilkins.

4.   Campbell, B.I.; Aguilar, D.; Colenso-Semple, L.M.; Hartke, K.; Fleming, A.R.; Fox, C.D.; Longstrom, J.M.; Rogers, G.E.; Mathas, D.B.; Wong, V.; Ford, S.; Gorman, J. Intermittent Energy Restriction Attenuates the Loss of Fat Free Mass in Resistance Trained Individuals. A Randomized Controlled Trial. J. Funct. Morphol. Kinesiol. 2020, 5, 19.

5.   Sainsbury A, Wood RE, Seimon RV, Hills AP, King NA, Gibson AA, Byrne NM. Rationale for novel intermittent dieting strategies to attenuate adaptive responses to energy restriction. Obes Rev. 2018 Dec;19 Suppl 1:47-60. doi: 10.1111/obr.12787. PMID: 30511512.

6.   Seimon RV, Roekenes JA, Zibellini J, Zhu B, Gibson AA, Hills AP, Wood RE, King NA, Byrne NM, Sainsbury A. Do intermittent diets provide physiological benefits over continuous diets for weight loss? A systematic review of clinical trials. Mol Cell Endocrinol. 2015 Dec 15;418 Pt 2:153-72. doi: 10.1016/j.mce.2015.09.014. Epub 2015 Sep 16. PMID: 26384657.

7.   Trexler, E.T., Smith-Ryan, A.E. & Norton, L.E. Metabolic adaptation to weight loss: implications for the athlete. J Int Soc Sports Nutr 11, 7 (2014). https://doi.org/10.1186/1550-2783-11-7

8.   MacLean PS, Higgins JA, Jackman MR, Johnson GC, Fleming-Elder BK, Wyatt HR, Melanson EL, Hill JO: Peripheral metabolic responses to prolonged weight reduction that promote rapid, efficient regain in obesity-prone rats. Am J Physiol Regul Integr Comp Physiol. 2006, 290: R1577-R1588. 10.1152/ajpregu.00810.2005.

9.   Rosenbaum M, Hirsch J, Gallagher DA, Leibel RL: Long-term persistence of adaptive thermogenesis in subjects who have maintained a reduced body weight. Am J Clin Nutr. 2008, 88: 906-912.

10.   De Maddalena C, Vodo S, Petroni A, Aloisi AM: Impact of testosterone on body fat composition. J Cell Physiol. 2012, 227: 3744-3748. 10.1002/jcp.24096.

11.   Morales FE Ms, Tinsley GM, Gordon PM. Acute and Long-Term Impact of High-Protein Diets on Endocrine and Metabolic Function, Body Composition, and Exercise-Induced Adaptations. J Am Coll Nutr. 2017 May-Jun;36(4):295-305. doi: 10.1080/07315724.2016.1274691. Epub 2017 Apr 26. PMID: 28443785.

12.   Stephen Welle, Usah Lilavivat, Robert G. Campbell. Thermic effect of feeding in man: Increased plasma norepinephrine levels following glucose but not protein or fat consumption. Metabolism, Volume 30, Issue 10. 1981. Available: https://doi.org/10.1016/0026-0495(81)90092-5.

13.   Tarnopolsky, M. (2006). Protein and amino needs for training and bulking up. In L. Burke & V. Deakin. (Eds.). Clinical sports nutrition (3rd ed.). (p. 73-111). NSW, Australia: McGraw Hill.

14.   Baechle, T. R., Earle, R. W. & Wathen, D. (2000). Resistance Training. In T. R. Baechle & R. W. Earle (Eds.). Essentials of strength training and conditioning (2nd ed.) (p. 395-421). Hong Kong: Human Kinetics.

15.   Wathen, D., Baechle, T. R. & Earle, R. W. (2000). Training variation: Periodization. In T. R. Baechle & R. W. Earle (Eds.). Essentials of strength training and conditioning (2nd ed.) (p. 395-421). Hong Kong: Human Kinetics

16.   Farnsworth, E., Luscombe, N. D., Noakes, M., Wittert, G., Argyiou, E. & Clifton, P. M. (2003). Effect of a protein, energy-restricted diet on body composition, glycemic control, and lipid concentrations in overweight and obese hyperinsulinemic men and women. Am J Clin Nutr, 78(1), 31-39.

17.   Aaberg, E. (1999). Resistance training instruction: Advanced principles and techniques for fitness professionals. United States of America: Human Kinetics.

18.   Increased protein intake reduces lean body mass loss during weight loss in athletes.Mettler S, Mitchell N, Tipton KD. Med Sci Sports Exerc. 2010 Feb; 42(2):326-37.

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