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What is the required energy deficit per unit weight loss?

Abstract

One of the most pervasive weight loss rules is that a cumulative energy deficit of 3500 kcal is required per pound of body weight loss, or equivalently 32.2 MJ kg−1. Under what conditions is it appropriate to use this rule of thumb and what are the factors that determine the cumulative energy deficit required per unit weight loss? Here, I examine this question using a modification of the classic Forbes equation that predicts the composition of weight loss as a function of the initial body fat and magnitude of weight loss. The resulting model predicts that a larger cumulative energy deficit is required per unit weight loss for people with greater initial body fat—a prediction supported by published weight loss data from obese and lean subjects. This may also explain why men can lose more weight than women for a given energy deficit since women typically have more body fat than men of similar body weight. Furthermore, additional weight loss is predicted to be associated with a lower average cumulative energy deficit since a greater proportion of the weight loss is predicted to result from loss of lean body mass, which has a relatively low energy density in comparison with body fat. The rule of thumb approximately matches the predicted energy density of lost weight in obese subjects with an initial body fat above 30 kg but overestimates the cumulative energy deficit required per unit weight loss for people with lower initial body fat.

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References

  1. McArdle WD . Exercise Physiology: Energy, Nutrition, and Human Performance, 4th edn. Williams & Wilkins: Baltimore, 1996.

    Google Scholar 

  2. Wishnofsky M . Caloric equivalents of gained or lost weight. Am J Clin Nutr 1958; 6: 542–546.

    Article  CAS  PubMed  Google Scholar 

  3. Forbes GB . Lean body mass-body fat interrelationships in humans. Nutr Rev 1987; 45: 225–231.

    Article  CAS  PubMed  Google Scholar 

  4. Forbes GB . Body fat content influences the body composition response to nutrition and exercise. Ann NY Acad Sci 2000; 904: 359–365.

    Article  CAS  PubMed  Google Scholar 

  5. Livesey G, Elia M . Estimation of energy expenditure, net carbohydrate utilization, and net fat oxidation and synthesis by indirect calorimetry: evaluation of errors with special reference to the detailed composition of fuels. Am J Clin Nutr 1988; 47: 608–628.

    Article  CAS  PubMed  Google Scholar 

  6. Hall KD . Body fat and fat-free mass inter-relationships: Forbes's theory revisited. Br J Nutr 2007; 97: 1059–1063.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  7. Entenman C, Goldwater WH, Ayres NS, Behnke Jr AR . Analysis of adipose tissue in relation to body weight loss in man. J Appl Physiol 1958; 13: 129–134.

    Article  CAS  PubMed  Google Scholar 

  8. Martin AD, Daniel MZ, Drinkwater DT, Clarys JP . Adipose tissue density, estimated adipose lipid fraction and whole body adiposity in male cadavers. Int J Obes Relat Metab Disord 1994; 18: 79–83.

    CAS  PubMed  Google Scholar 

  9. Keys A . The Biology of Human Starvation. University of Minnesota Press: Minneapolis, 1950.

    Book  Google Scholar 

  10. Leone PA, Gallagher D, Wang J, Heymsfield SB . Relative overhydration of fat-free mass in postobese versus never-obese subjects. Ann NY Acad Sci 2000; 904: 514–519.

    Article  CAS  PubMed  Google Scholar 

  11. Sergi G, Lupoli L, Busetto L, Volpato S, Coin A, Bertani R, et al. Changes in fluid compartments and body composition in obese women after weight loss induced by gastric banding. Ann Nutr Metab 2003; 47: 152–157.

    Article  CAS  PubMed  Google Scholar 

  12. Zimmerman ME, Andersson H, Lundell L, Olbe L . Alterations in body composition after gastroplasty for morbid obesity. Scand J Gastroenterol 1990; 25: 263–268.

    CAS  PubMed  Google Scholar 

  13. MacKay E, Bergman H . The amount of water stored with glycogen in the liver. J Biol Chem 1934; 105: 59–62.

    CAS  Google Scholar 

  14. McBride J, Guest M, Scott E . The storage of the major liver components; emphasizing the relationship of glycogen to water in the liver and the hydration of glycogen. J Biol Chem 1941; 139: 943–952.

    CAS  Google Scholar 

  15. Fullerton GD, Kanal KM, Cameron IL . On the osmotically unresponsive water compartment in cells. Cell Biol Int 2006; 30: 74–77.

    Article  CAS  PubMed  Google Scholar 

  16. Fullerton GD, Amurao MR . Evidence that collagen and tendon have monolayer water coverage in the native state. Cell Biol Int 2006; 30: 56–65.

    Article  CAS  PubMed  Google Scholar 

  17. Corless R, Gonnet G, Hare D, Jeffery D, Knuth D . On the lambert W function. Adv Comput Math 1996; 5: 329–359.

    Article  Google Scholar 

  18. Benedetti G, Mingrone G, Marcoccia S, Benedetti M, Giancaterini A, Greco AV et al. Body composition and energy expenditure after weight loss following bariatric surgery. J Am Coll Nutr 2000; 19: 270–274.

    Article  CAS  PubMed  Google Scholar 

  19. Das SK, Roberts SB, McCrory MA, Hsu LK, Shikora SA, Kehayias JJ et al. Long-term changes in energy expenditure and body composition after massive weight loss induced by gastric bypass surgery. Am J Clin Nutr 2003; 78: 22–30.

    Article  CAS  PubMed  Google Scholar 

  20. Strauss BJ, Marks SJ, Growcott JP, Stroud DB, Lo CS, Dixon JB et al. Body composition changes following laparoscopic gastric banding for morbid obesity. Acta Diabetologica 2003; 40 (Suppl. 1): S266–S269.

    Article  PubMed  Google Scholar 

  21. Tacchino RM, Mancini A, Perrelli M, Bianchi A, Giampietro A, Milardi D et al. Body composition and energy expenditure: relationship and changes in obese subjects before and after biliopancreatic diversion. Metab: Clin Exp 2003; 52: 552–558.

    Article  CAS  Google Scholar 

  22. van Gemert WG, Westerterp KR, van Acker BA, Wagenmakers AJ, Halliday D, Greve JM et al. Energy, substrate and protein metabolism in morbid obesity before, during and after massive weight loss. Int J Obes Relat Metab Disord 2000; 24: 711–718.

    Article  CAS  PubMed  Google Scholar 

  23. Wadstrom C, Backman L, Forsberg AM, Nilsson E, Hultman E, Reizenstein P et al. Body composition and muscle constituents during weight loss: studies in obese patients following gastroplasty. Obes Surg 2000; 10: 203–213.

    Article  CAS  PubMed  Google Scholar 

  24. Carella MJ, Rodgers CD, Anderson D, Gossain VV . Serial measurements of body composition in obese subjects during a very-low-energy diet (VLED) comparing bioelectrical impedance with hydrodensitometry. Obes Res 1997; 5: 250–256.

    Article  CAS  PubMed  Google Scholar 

  25. de Boer JO, van Es AJ, Roovers LC, van Raaij JM, Hautvast JG . Adaptation of energy metabolism of overweight women to low-energy intake, studied with whole-body calorimeters. Am J Clin Nutr 1986; 44: 585–595.

    Article  CAS  PubMed  Google Scholar 

  26. Stanko RT, Tietze DL, Arch JE . Body composition, nitrogen metabolism, and energy utilization with feeding of mildly restricted (4.2 MJ d−1) and severely restricted (2.1 MJ d−1) isonitrogenous diets. Am J Clin Nutr 1992; 56: 636–640.

    Article  CAS  PubMed  Google Scholar 

  27. Webb P, Abrams T . Loss of fat stores and reduction in sedentary energy expenditure from undereating. Hum Nutr 1983; 37: 271–282.

    CAS  Google Scholar 

  28. Friedl KE, Moore RJ, Martinez-Lopez LE, Vogel JA, Askew EW, Marchitelli LJ et al. Lower limit of body fat in healthy active men. J Appl Physiol 1994; 77: 933–940.

    Article  CAS  PubMed  Google Scholar 

  29. Friedlander AL, Braun B, Pollack M, MacDonald JR, Fulco CS, Muza SR et al. Three weeks of caloric restriction alters protein metabolism in normal-weight, young men. Am J Physiol 2005; 289: E446–E455.

    CAS  Google Scholar 

  30. Hoyt RW, Opstad PK, Haugen AH, DeLany JP, Cymerman A, Friedl KE . Negative energy balance in male and female rangers: effects of 7 d of sustained exercise and food deprivation. Am J Clin Nutr 2006; 83: 1068–1075.

    Article  CAS  PubMed  Google Scholar 

  31. Pietrobelli A, Allison DB, Heshka S, Heo M, Wang ZM, Bertkau A et al. Sexual dimorphism in the energy content of weight change. Int J Obes Relat Metab Disord 2002; 26: 1339–1348.

    Article  CAS  PubMed  Google Scholar 

  32. Doucet E, Imbeault P, St-Pierre S, Almeras N, Mauriege P, Despres JP et al. Greater than predicted decrease in energy expenditure during exercise after body weight loss in obese men. Clin Sci (London) 2003; 105: 89–95.

    Article  Google Scholar 

  33. Doucet E, St-Pierre S, Almeras N, Despres JP, Bouchard C, Tremblay A . Evidence for the existence of adaptive thermogenesis during weight loss. Br J Nutr 2001; 85: 715–723.

    Article  CAS  PubMed  Google Scholar 

  34. Dulloo AG, Seydoux J, Jacquet J . Adaptive thermogenesis and uncoupling proteins: a reappraisal of their roles in fat metabolism and energy balance. Physiol Behav 2004; 83: 587–602.

    Article  CAS  PubMed  Google Scholar 

  35. Leibel RL, Rosenbaum M, Hirsch J . Changes in energy expenditure resulting from altered body weight. N Engl J Med 1995; 332: 621–628.

    Article  CAS  PubMed  Google Scholar 

  36. Weinsier RL, Nagy TR, Hunter GR, Darnell BE, Hensrud DD, Weiss HL . Do adaptive changes in metabolic rate favor weight regain in weight-reduced individuals? An examination of the set-point theory. Am J Clin Nutr 2000; 72: 1088–1094.

    Article  CAS  PubMed  Google Scholar 

  37. Heymsfield SB, Harp JB, Reitman ML, Beetsch JW, Schoeller DA, Erondu N et al. Why do obese patients not lose more weight when treated with low-calorie diets? A mechanistic perspective. Am J Clin Nutr 2007; 85: 346–354.

    Article  CAS  PubMed  Google Scholar 

  38. Hansen D, Dendale P, Berger J, van Loon LJ, Meeusen R . The effects of exercise training on fat-mass loss in obese patients during energy intake restriction. Sports Med (Auckland, NZ) 2007; 37: 31–46.

    Article  Google Scholar 

  39. Layman DK, Evans E, Baum JI, Seyler J, Erickson DJ, Boileau RA . Dietary protein and exercise have additive effects on body composition during weight loss in adult women. J Nutr 2005; 135: 1903–1910.

    Article  CAS  PubMed  Google Scholar 

  40. Stiegler P, Cunliffe A . The role of diet and exercise for the maintenance of fat-free mass and resting metabolic rate during weight loss. Sports Med (Auckland, NZ) 2006; 36: 239–262.

    Article  Google Scholar 

  41. Hall KD . Computational model of in vivo human energy metabolism during semistarvation and refeeding. Am J Physiol 2006; 291: E23–E37.

    CAS  Google Scholar 

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Acknowledgements

This work was supported by the Intramural Research Program of the NIH, NIDDK.

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Correspondence to K D Hall.

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Hall, K. What is the required energy deficit per unit weight loss?. Int J Obes 32, 573–576 (2008). https://doi.org/10.1038/sj.ijo.0803720

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