I recently attended the International Society for Sports Nutrition (ISSN) annual meeting in Florida and wanted to share some brand new data on what happens when slashing calories by 50 percent for body composition. My good friend Dr Bill Campbell and his lab performed the research.


When many at Planet Fitness opt to change their body composition by losing fat, they also tend to lose muscle. I’ve published on some of this data in the past in the “Dietary Protein and Resistance Exercise” formal academic book.

The two main ways to reduce this loss of muscle are 1) strength training (aka lift stuff) and 2) higher protein.

Even then, there are limited data as how well those two methods will work when you get super aggressive with cutting calories.

Dr. Campbell’s Study

Dr. Campbell’s lab did a short experiment where after a 2 week run in period, they had the subjects cut their calories by 50% for two weeks.

As per above, they kept weight training and ate higher protein at 1 gram/pound of bodyweight.

What did they find?

They did they lose muscle (or more formally called lean body mass/LBM).

Oh poop.

There was a catch, though.

The initial measure did show a loss of LBM, however when they corrected for the internal water difference, this loss of LBM went poof like doughnuts at the front desk of PF.

In English, the measures looked like they lost LBM, but it was a shift in fluid. There was no real loss of LBM.

Takeaway on Slashing Calories by 50 Percent for Body Composition

The main take away here is that we have more data now that a very short term aggressive cut (slashing calories by 50 percent for body composition) while lifting and eating lots of protein, may not result in a LBM loss.

Like all research, this is just one piece of the puzzle, and I am not recommending that you crash diet right now to get ready for the beach in two weeks. However, a short term more aggressive approach may not strip LBM off you either. Here’s another study from ISSN a few years ago about including high carb days during calorie restriction.

Keep lifting and eating protein.

Rock on!

Dr. Mike T Nelson

Dr. Mike T Nelson

Dr. Mike T Nelson

PhD, MSME, CISSN, CSCS Carrick Institute Adjunct Professor Dr. Mike T. Nelson has spent 18 years of his life learning how the human body works, specifically focusing on how to properly condition it to burn fat and become stronger, more flexible, and healthier. He’s has a PhD in Exercise Physiology, a BA in Natural Science, and an MS in Biomechanics. He’s an adjunct professor and a member of the American College of Sports Medicine. He’s been called in to share his techniques with top government agencies. The techniques he’s developed and the results Mike gets for his clients have been featured in international magazines, in scientific publications, and on websites across the globe.

  • PhD in Exercise Physiology
  • BA in Natural Science
  • MS in Biomechanics
  • Adjunct Professor in Human
  • Performance for Carrick Institute for Functional Neurology
  • Adjunct Professor and Member of American College of Sports Medicine
  • Instructor at Broadview University
  • Professional Nutritional
  • Member of the American Society for Nutrition
  • Professional Sports Nutrition
  • Member of the International Society for Sports Nutrition
  • Professional NSCA Member
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