Hi! I'm your SANE concierge. What can I help you find today?

Study Shows Up To 70% of Weight Lost by Dieting Comes from Burning Muscle


“The reduction of energy intake continues to be the basis of…weight reduction programs…[The results] are known to be poor and not long-lasting.” – George Bray, Pennington Biomedical Research Center

As we touched on last week, eating less does not create the need to burn body fat. It creates the need for the body to slow down. Contrary to popular opinion, the body hangs on to body fat. Instead, it burns muscle tissue, and that worsens the metabolic issue causing weight gain. Only as a last resort, if the body has no other option, it may also burn a bit of body fat.

Why does the body hang on to body fat and burn muscle? To answer that question, let’s look at it another way. What does our body want more of when it thinks we are starving? Stored energy. What is a great source of stored energy? Body fat. So when our body thinks we are starving, does it want to get rid of or hold on to body fat? It wants to hold on.

Next, what does our body want less of when we are starving? It wants less tissue which burns a lot of calories. What type of tissue burns a lot of calories? Muscle tissue. So when our body thinks we are starving, it gets rid of calorie-hungry muscle tissue. Studies show that up to 70% of the weight lost while eating less comes from burning muscle—not body fat.

Burning all this muscle means that starving ourselves leads to more body fat—not less—over the long term. As soon as we stop starving ourselves, we have all the calories we used to have but need less of them, thanks to all that missing muscle and our slowed-down metabolism. Now our body sees eating a normal amount as overeating and creates new body fat.

“It is only the rate of weight regain, not the fact of weight regain, that appears open to debate.” – D.M. Garner, Michigan State University

In the Journal of the American Medical Association, researcher G.L. Thorpe tells us that eating less does not make us lose weight, “…by selective reduction of adipose deposits [body fat], but by wasting of all body tissues…therefore, any success obtained must be maintained by chronic under-nourishment.” It is not practical or healthy to keep ourselves “chronically under-nourished,” so we don’t. Instead, we yo-yo diet. That is why eating less of a traditional diet is not an effective long-term fat loss approach. And that is why eating more–but smarter–is an effective long-term fat loss approach.


  1. A.C. Guyton: ‘Textbook of medical physiology’ 3rd edn. Philadelphia: Saunders, 1966
  2. Ballor DL, Katch VL, Becque MD, Marks CR. Resistance strength training during caloric restriction enhances lean body weight maintenance. Am J Clin Nutr. 1988 Jan;47(1):19-25. PubMed PMID: 3337037.
  3. Björntorp P, Yang MU. Refeeding after fasting in the rat: effects on body composition and food efficiency. Am J Clin Nutr. 1982 Sep;36(3):444-9. PubMed PMID: 7113950.
  4. Bray GA: Effect of caloric restriction on energy expenditure in obese patients. Lancet 1969; 2:397-398
  5. Bray, George and Claude Bouchard. Handbook of Obesity. Oxford Oxfordshire: Oxford University Press, 1998.
  6. Dulloo AG, Girardier L. Adaptive changes in energy expenditure during refeeding following low-calorie intake: evidence for a specific metabolic component favoring fat storage. Am J Clin Nutr. 1990 Sep;52(3):415-20. PubMed PMID: 2393003.
  7. Dulloo AG, Jacquet J, Girardier L. Autoregulation of body composition during weight recovery in human: The Minnesota Experiment revisited. Int J Obes Relat Metab Disord. 1996 May;20(5):393-405. PubMed PMID: 8696417.
  8. Dulloo AG, Girardier L. Adaptive changes in energy expenditure during refeeding following low-calorie intake: evidence for a specific metabolic component favoring fat storage. Am J Clin Nutr. 1990 Sep;52(3):415-20. PubMed PMID: 2393003.
  9. Friedman JM, Halaas JL. Leptin and the regulation of body weight in mammals. Nature. 1998 Oct 22;395(6704):763-70. Review. PubMed PMID: 9796811.
  10. Garner DM, Wooley SC. Confronting the failure of behavioral and dietary treatments for obesity. Clin Psychol Rev. 1991;11:729–780. doi: 10.1016/0272-7358(91)90128-H.
  11. Geissler CA, Miller DS, Shah M: The daily metabolic rate of the postobese and the lean. Am J Clin Nutr 1987; 45:914-920
  12. Hunter GR, Wetzstein CJ, Fields DA, Brown A, Bamman MM. Resistance training increases total energy expenditure and free-living physical activity in older adults. J Appl Physiol. 2000 Sep;89(3):977-84. PubMed PMID: 10956341.
  13. Jen KL, Lu H, Savona L, Watkins A, Shaw M. Long-term weight cycling reduces body weight and fat free mass, but not fat mass in female Wistar rats. Int J Obes Relat Metab Disord. 1995 Oct;19(10):699-708. PubMed PMID: 8589763.
  14. Jéquier E. Energy expenditure in obesity. Clin Endocrinol Metab. 1984 Nov;13(3):563-80. Review. PubMed PMID: 6391755.
  15. Jéquier E. Leptin signaling, adiposity, and energy balance. Ann N Y Acad Sci. 2002 Jun;967:379-88. Review. PubMed PMID: 12079865.
  16. Kelesidis T, Kelesidis I, Chou S, Mantzoros CS. Narrative review: The role of leptin in human physiology: emerging clinical applications. Ann Intern Med. 2010 Jan 19;152(2):93-100. Review. PubMed PMID: 20083828; PubMed Central PMCID:PMC2829242.
  17. Keys, Ancel. The Biology of Human Starvation: Volume I. Minneapolis: University of Minnesota Press, 1950. Print.
  18. Leibel RL, Hirsch J: Diminished energy requirements in reduced-obese patients. Metabolism 1984; 33:164-170
  19. Leibel RL, Rosenbaum M, Hirsch J. Changes in energy expenditure resulting from altered body weight. N Engl J Med. 1995 Mar 9;332(10):621-8. Erratum in: N Engl J Med 1995 Aug 10;333(6):399. PubMed PMID: 7632212.
  20. Muscle logic : escalating density training changes the rules for maximum-impact strength training / Charles Staley.
  21. Poehlman ET, Mepoundy C. Resistance training and energy balance. Int J Sport Nutr. 1998 Jun;8(2):143-59. Review. PubMed PMID: 9637193.
  22. Poehlman ET, Mepoundy CL, Goran MI. The impact of exercise and diet restriction on daily energy expenditure. Sports Med. 1991 Feb;11(2):78-101. Review.
  23. Ravussin E, Burnand B, Schutz Y, et al: Energy expenditure before and during energy restriction in obese patients. Am J Clin Nutr 1985; 41:753-759
  24. 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 Oct;88(4):906-12. PubMed PMID: 18842775.
  25. Rosenbaum M, Murphy EM, Heymsfield SB, Matthews DE, Leibel RL. Low dose leptin administration reverses effects of sustained weight-reduction on energy expenditure and circulating concentrations of thyroid hormones. J Clin Endocrinol Metab. 2002 May;87(5):2391-4. PubMed PMID: 11994393.
  26. Shah M, Miller DS, Geissler CA. Lower metabolic rates of post-obese versus lean women: Thermogenesis, basal metabolic rate and genetics. Eur J Clin Nutr. 1988 Sep;42(9):741-52. PubMed PMID: 3181107.
  27. Thorpe GL. Treating overweight patients. J Am Med Assoc. 1957 Nov 16;165(11):1361-5. PubMed PMID: 13475044.
  28. Walks D, Lavau M, Presta E, Yang MU, Björntorp P. Refeeding after fasting in the rat: effects of dietary-induced obesity on energy balance regulation. Am J Clin Nutr. 1983 Mar;37(3):387-95. PubMed PMID: 6338694.
  29. Weigle DS, Sande KJ, Iverius PH, Monsen ER, Brunzell JD. Weight loss leads to  a marked decrease in nonresting energy expenditure in ambulatory human subjects.  Metabolism. 1988 Oct;37(10):930-6. PubMed PMID: 3173112.