The Importance of Energy Balance

US Endocrinology, 2013;9(1):27-31 DOI:


Globally, bodyweight and obesity are rising in both the developing and developed world. To maintain a stable bodyweight, energy intake must, over time, exactly equal energy expenditure, a state known as energy balance. an understanding of the physiologic control of energy balance may be useful for designing interventions to tackle the obesity epidemic worldwide. obesity occurs when the body’s energy balance is positive (i.e. when energy intake exceeds energy expenditure). human physiology is biased toward maintaining energy balance at high levels of energy intake and expenditure. as a result, strategies to combat obesity should include a focus on increasing physical activity along with strategies for modifying food intake. an understanding of energy balance leads to the conclusion that prevention of weight gain should be easier than treatment of obesity. components of energy balance are interdependent, and weight loss requires major behavior changes, which trigger compensatory decreases in energy expenditure that facilitate weight regain. Prevention of weight gain can be accomplished by smaller behavior changes. in addition to being easier to sustain than larger behavior changes, smaller ones produce less compensation by the energy balance regulatory system. it has been estimated that relatively small changes in energy intake and expenditure totaling 100 kcal per day could arrest weight gain in most people. interventions that advocate small changes have shown promising levels of success.

Support: The publication of this article was supported by The Coca-Cola Company. The views and opinions expressed are those of the authors and not necessarily those of The Coca-Cola Company.
Keywords: Energy balance, obesity, physical activity
Disclosure: James O Hill has advisory roles for General Mills, McDonald’s, McCormick, and Wrigley; grant support from the American Beverage Association (ABA); and research support from GI Dynamics and Novo Nordisk. Holly R Wyatt has grant support from the ABA; research support from GI Dynamics and Novo Nordisk; and advisory roles for Eisai, Retrofit, and Wellspring. John C Peters has grant support from the ABA.
Received: March 05, 2013 Accepted April 26, 2013
Correspondence: James O Hill, Anschutz Health and Wellness Center, 12348 E. Montview Blvd. Mailstop C263, Aurora CO 80045 USA. E:

Obesity is a growing problem with many associated health risks and associated costs.1,2 During 1971 to 2000, the prevalence of obesity in the US increased from 14.5 % to 30.9 %.3 In the US, more than 37 % of adults and almost 17 % of youths were obese in 2009–10.4 Currently over 1.1 billion adults worldwide are overweight, and of these, 312 million are obese.5 Analysis of data from the US Longitudinal (CARDIA study)6 and cross-sectional (NHANES)7 studies to determine the distribution of weight gain over time, found that the average US adult is gaining 0.5–1 kg/year.8 This article will examine the concept of energy balance and its relevance in combating the obesity epidemic. The Concept of Energy Balance The concept of energy balance is based on the fundamental thermodynamic principle that energy cannot be destroyed, and can only be gained, lost, or stored by an organism. Energy balance is defined as the state achieved when the energy intake equals energy expenditure. This concept may be used to demonstrate how bodyweight will change over time in response to changes in energy intake and expenditure. When the body is in energy balance, bodyweight is stable.9,10 Humans take in energy through the intake of food and drink, and expend energy through the resting metabolic rate (RMR)—the thermic effect (TEF) of food and physical activity. The RMR is the energy expenditure required for maintaining normal body functions and homeostasis. The RMR is proportional to body mass, in particular fat-free mass. TEF refers to the energy required to absorb, digest, and metabolize the food consumed and typically accounts for 8–10 % of daily energy expenditure. The energy expended due to physical activity (EEact) accounts for energy that is expended in addition to the RMR and TEF, including voluntary exercise, shivering, postural control, and voluntary movement. It is calculated by multiplying the energy expenditure of an activity by the time spent performing it, and is the most variable component of energy expenditure.10 The more sedentary the individual is, the lower the effect of physical activity. This may be as low as 100 calories per day, whereas elite athletes may expend 3,000 calories per day of physical activity. The decline in energy expenditure that occurs with advancing age is mainly the results of declining lean body mass, which reduces TEF and EEact. Disturbances in energy balance cause changes in body mass, although the timeframe over which this occurs varies between individuals and may explain the large interindividual response to weight-loss interventions. A positive energy balance, in which energy intake exceeds expenditure causes weight gain, with 60–80 % of the resulting weight gain being attributable to body fat.11 In negative energy balance, when energy Figure 1: Continued Weight Gain in the Population According to the Concept of Energy Balance14
Figure 2: Relationship between Energy Balance and Physical Activity Level10
1. Finkelstein EA, Trogdon JG, Cohen JW, et al., Annual medical spending attributable to obesity: Payer-and service-specific estimates, Health Affairs, 2009a;28:w822–w31.
2. Finkelstein EA, Trogdon JG, Cohen JW, et al., Annual medical spending attributable to obesity: payer-and service-specific estimates, Health Aff (Millwood), 2009b;28:w822–31.
3. Flegal KM, Carroll MD, Ogden CL, et al., Prevalence and trends in obesity among US adults, 1999–2000, JAMA, 2002;288:1723–7.
4. Ogden CL, Carroll MD, Kit BK, et al., Prevalence of obesity in the United States, 2009–2010, NCHS Data Brief, 2012;1–8.
5. Haslam DW, James WP, Obesity, Lancet, 2005;366:1197–209.
6. Hankinson AL, Daviglus ML, Bouchard C, et al., Maintaining a high physical activity level over 20 years and weight gain, JAMA, 2010;304:2603–10.
7. Williamson DF, Madans J, Anda RF, et al., Recreational physical activity and ten-year weight change in a US national cohort, Int J Obes Relat Metab Disord, 1993;17:279–86.
8. Hill JO, Wyatt HR, Reed GW, et al., Obesity and the environment: where do we go from here?, Science, 2003;299:853–5.
9. Hafekost K, Lawrence D, Mitrou F, et al., Tackling overweight and obesity: does the public health message match the science?, BMC Med, 2013;11:41.
10. Hill JO, Wyatt HR, Peters JC, Energy balance and obesity, Circulation, 2012;126:126–32.
11. Hill JO, Commerford R, Physical activity, fat balance, and energy balance, Int J Sport Nutr, 1996;6:80–92.
12. Lustig R, The Efferent Arm of the Energy Balance Regulatory Pathway: Neuroendocrinology and Pathology Energy Metabolism and Obesity Contemporary Endocrinology, P A Donohoue (Ed.), Totowa, NJ: Humana Press Inc., 2008;69–85.
13. Martin CK, Heilbronn LK, de Jonge L, et al., Effect of calorie restriction on resting metabolic rate and spontaneous physical activity, Obesity (Silver Spring), 2007;15:2964–73.
14. Hill JO, Peters JC, Wyatt HR, Using the energy gap to address obesity: a commentary, J Am Diet Assoc, 2009;109:1848–53.
15. Mayer J, Roy P, Mitra KP, Relation between caloric intake, body weight, and physical work: studies in an industrial male population in West Bengal, Am J Clin Nutr, 1956;4:169–75.
16. Mayer J, Marshall NB, Vitale JJ, et al., Exercise, food intake and body weight in normal rats and genetically obese adult mice, Am J Physiol, 1954;177:544–8.
17. King NA, Horner K, Hills AP, et al., The interaction between exercise, appetite, and food intake: implications for weight control, American Journal of Lifestyle Medicine, published online February 6, 2013 (available at: content/early/2013/02/05/1559827613475584.abstract).
18. Schubert MM, Desbrow B, Sabapathy S, Leveritt M, Acute exercise and subsequent intake: a meta-analysis, Appetite, 2013;63:92–104.
19. Flatt JP, Misconceptions in body weight regulation: implications for the obesity pandemic, Crit Rev Clin Lab Sci, 2012;49:150–65.
20. Swinburn B, Sacks G, Ravussin E, Increased food energy supply is more than sufficient to explain the US epidemic of obesity, Am J Clin Nutr, 2009;90:1453–6.
21. Besson H, Ekelund U, Luan J, et al., A cross-sectional analysis of physical activity and obesity indicators in European participants of the EPIC-PANACEA study, Int J Obes (Lond), 2009;33:497–506.
22. French SA, Jeffery RW, Forster JL, et al., Predictors of weight change over two years among a population of working adults: the Healthy Worker Project, Int J Obes Relat Metab Disord, 1994;18:145–54.
23. May AM, Bueno-de-Mesquita HB, Boshuizen H, et al., Effect of change in physical activity on body fatness over a 10-y period in the Doetinchem Cohort Study, Am J Clin Nutr, 2010;92:491–9.
24. Waller K, Kaprio J, Kujala UM, Associations between longterm physical activity, waist circumference and weight gain: a 30-year longitudinal twin study, Int J Obes (Lond), 2008;32:353–61.
25. Ham SA, Kruger J, Tudor-Locke C, Participation by US adults in sports, exercise, and recreational physical activities, J Phys Act Health, 2009;6:6–14.
26. Bassett DR, Schneider PL, Huntington GE, Physical activity in an Old Order Amish community, Med Sci Sports Exerc, 2004;36:79–85.
27. Brown WJ, Williams L, Ford JH, et al., Identifying the energy gap: magnitude and determinants of 5-year weight gain in midage women, Obes Res, 2005;13:1431–41.
28. Blundell JE, King NA, Physical activity and regulation of food intake: current evidence, Med Sci Sports Exerc, 1999;31:S573– 83.
29. Stubbs RJ, Hughes DA, Johnstone AM, et al., A decrease in physical activity affects appetite, energy, and nutrient balance in lean men feeding ad libitum, Am J Clin Nutr, 2004;79:62–9.
30. Rodearmel SJ, Wyatt HR, Stroebele N, et al., Small changes in dietary sugar and physical activity as an approach to preventing excessive weight gain: the America on the Move family study, Pediatrics, 2007;120:e869–79.
31. Sorensen TI, Conference on “Multidisciplinary approaches to nutritional problems”. Symposium on “Diabetes and health”. Challenges in the study of causation of obesity, Proc Nutr Soc, 2009;68:43–54.
32. Dulloo AG, Jacquet J, Adaptive reduction in basal metabolic rate in response to food deprivation in humans: a role for feedback signals from fat stores, Am J Clin Nutr, 1998;68:599–606.
33. Schwartz MW, Woods SC, Porte D, Jr., et al., Central nervous system control of food intake, Nature, 2000;404:661–71.
34. Wing RR, Hill JO, Successful weight loss maintenance, Annu Rev Nutr, 2001;21:323–41.
35. Jeffery RW, Drewnowski A, Epstein LH, et al., Long-term maintenance of weight loss: current status, Health Psychol, 2000;19:5–16.
36. Mann T, Tomiyama AJ, Westling E, et al., Medicare’s search for effective obesity treatments: diets are not the answer, Am Psychol, 2007;62:220–33.
37. Hall KD, Sacks G, Chandramohan D, et al., Quantification of the effect of energy imbalance on bodyweight, Lancet, 2011;378:826–37.
38. Wang YC, Gortmaker SL, Sobol AM, et al., Estimating the energy gap among US children: a counterfactual approach, Pediatrics, 2006;118:e1721–33.
39. Mozaffarian D, Hao T, Rimm EB, et al., Changes in diet and lifestyle and long-term weight gain in women and men, N Engl J Med, 2011;364:2392–404.
40. Hill JO, Can a small-changes approach help address the obesity epidemic? A report of the Joint Task Force of the American Society for Nutrition, Institute of Food Technologists, and International Food Information Council, Am J Clin Nutr, 2009;89:477–84.
41. Wyatt HR, Peters JC, Reed GW, et al., Using electronic step counters to increase lifestyle physical activity: Colorado on the Move, J Phys Act Health, 2004;1:181–91.
42. Rodearmel SJ, Wyatt HR, Barry MJ, et al., A family-based approach to preventing excessive weight gain, Obesity (Silver Spring), 2006;14:1392–401.
43. Stroebele N, de Castro JM, Stuht J, et al., A small-changes approach reduces energy intake in free-living humans, J Am Coll Nutr, 2009;28:63–8.
44. Di Pietro L, Dziura J, Blair SN, Estimated change in physical activity level (PAL) and prediction of 5-year weight change in men: the Aerobics Center Longitudinal Study, Int J Obes Relat Metab Disord, 2004;28:1541–7.
45. Wagner A, Simon C, Ducimetiere P, et al., Leisure-time physical activity and regular walking or cycling to work are associated with adiposity and 5 y weight gain in middle-aged men: the PRIME Study, Int J Obes Relat Metab Disord, 2001;25:940–48.
Keywords: Energy balance, obesity, physical activity