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Book 1 · Energy balance and dynamic weight-change modelling · Rung 1Book 1
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Obesity Expertise · Book 1

Energy balance and dynamic weight-change modellingRung 1 · Introductory

Why energy balance is arithmetically true and practically insufficient

Dr. Harsh Maheshwari · Version 1.2 · updated 24 September 2026 · CC BY-NC-SA 4.0

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Why this book

Every claim about body weight passes, sooner or later, through energy balance. This book teaches the one piece of physics that no argument about obesity is allowed to break: body fat is stored chemical energy, energy is conserved, so fat changes only when what comes in differs from what goes out. It also teaches why that true sentence is not an instruction: intake and expenditure are outputs of a regulated body, not dials you set.

How to read it

Read Book 0 first, or at least the sections this book names as it goes. Then read this one in order: each section assumes everything before it. Do every exercise before you read on.

1 Body fat as stored chemical energy; fat mass and fat-free mass

2 How much energy a kilogram of body fat holds

3 A day of intake and a day of expenditure: the sizes

4 What expenditure is made of, and why a bigger body spends more

5 The accounting identity for a body

6 The first law for a body in one sentence, without a lever

7 Sizing an imbalance, and the static rule

8 Spotting a claim that breaks conservation

9 Intake and expenditure are outputs of a regulated system

10 Arithmetically true, practically insufficient

References 95
  1. Betts, J. Gordon and Young, Kelly A. and Wise, James A. and Johnson, Eddie and Poe, Brandon and Kruse, Dean H. and Korol, Oksana and Johnson, Jody E. and Womble, Mark and DeSaix, Peter. Anatomy and Physiology 2e. 2022. § 24.3 Lipid Metabolism, the paragraph on chylomicrons. https://openstax.org/books/anatomy-and-physiology-2e (accessed 2026-09-23).
  2. Betts, J. Gordon and Young, Kelly A. and Wise, James A. and Johnson, Eddie and Poe, Brandon and Kruse, Dean H. and Korol, Oksana and Johnson, Jody E. and Womble, Mark and DeSaix, Peter. Anatomy and Physiology 2e. 2022. § 24.3 Lipid Metabolism, the closing paragraph on lipogenesis. https://openstax.org/books/anatomy-and-physiology-2e (accessed 2026-09-23).
  3. Hall, Kevin D. What is the required energy deficit per unit weight loss?. PMID 17848938, PMC2376744 (NIH author manuscript NIHMS47767). Quoted from the author manuscript. Energy density of fat mass change, the paragraph on adipose tissue. https://pmc.ncbi.nlm.nih.gov/articles/PMC2376744/ (accessed 2026-09-23).
  4. Hall, Kevin D. What is the required energy deficit per unit weight loss?. PMID 17848938, PMC2376744 (NIH author manuscript NIHMS47767). Quoted from the author manuscript. Energy density of fat mass change, the paragraph before it, on the Forbes equation. https://pmc.ncbi.nlm.nih.gov/articles/PMC2376744/ (accessed 2026-09-23).
  5. Hall, Kevin D. What is the required energy deficit per unit weight loss?. PMID 17848938, PMC2376744 (NIH author manuscript NIHMS47767). Quoted from the author manuscript. Opening paragraphs, on what an energy deficit draws on. https://pmc.ncbi.nlm.nih.gov/articles/PMC2376744/ (accessed 2026-09-23).
  6. Hall, Kevin D and Guo, Juen. Obesity energetics: body weight regulation and the effects of diet composition. PMID 28193517, PMC5568065 (NIH author manuscript). Quoted from the author manuscript text. Figure 1 caption. https://pmc.ncbi.nlm.nih.gov/articles/PMC5568065/ (accessed 2026-09-23).
  7. Hall, Kevin D and Guo, Juen. Obesity energetics: body weight regulation and the effects of diet composition. PMID 28193517, PMC5568065 (NIH author manuscript). Quoted from the author manuscript text. Resting Energy Expenditure, first paragraph. https://pmc.ncbi.nlm.nih.gov/articles/PMC5568065/ (accessed 2026-09-23).
  8. Hall, Kevin D and Guo, Juen. Obesity energetics: body weight regulation and the effects of diet composition. PMID 28193517, PMC5568065 (NIH author manuscript). Quoted from the author manuscript text. Components of Daily Energy Expenditure, opening sentence. https://pmc.ncbi.nlm.nih.gov/articles/PMC5568065/ (accessed 2026-09-23).
  9. Hall, Kevin D and Guo, Juen. Obesity energetics: body weight regulation and the effects of diet composition. PMID 28193517, PMC5568065 (NIH author manuscript). Quoted from the author manuscript text. Resting Energy Expenditure, first paragraph, on obesity. https://pmc.ncbi.nlm.nih.gov/articles/PMC5568065/ (accessed 2026-09-23).
  10. Hall, Kevin D. What is the required energy deficit per unit weight loss?. PMID 17848938, PMC2376744 (NIH author manuscript NIHMS47767). Quoted from the author manuscript. Energy density of fat mass change, the paragraph on adipose tissue, next sentence. https://pmc.ncbi.nlm.nih.gov/articles/PMC2376744/ (accessed 2026-09-23).
  11. Betts, J. Gordon and Young, Kelly A. and Wise, James A. and Johnson, Eddie and Poe, Brandon and Kruse, Dean H. and Korol, Oksana and Johnson, Jody E. and Womble, Mark and DeSaix, Peter. Anatomy and Physiology 2e. 2022. § 23.6 Accessory Organs in Digestion, the paragraph on hepatocytes. https://openstax.org/books/anatomy-and-physiology-2e (accessed 2026-09-23).
  12. National Institute of Standards and Technology. Guide for the Use of the International System of Units (SI), NIST Special Publication 811, Appendix B.8 and Footnotes. The avoirdupois pound: 0.453 592 37 kg exactly. Footnotes page updated 18 August 2025. Footnotes page, the pound footnote. NIST. https://www.nist.gov/pml/special-publication-811/nist-guide-si-footnotes (accessed 2026-09-23).
  13. Food and Agriculture Organization of the United Nations. Food energy — methods of analysis and conversion factors. 2003. ch. 3, s.3.5.1, the Atwater general factor system. https://www.fao.org/4/y5022e/y5022e04.htm.
  14. Food and Agriculture Organization of the United Nations. Food energy — methods of analysis and conversion factors. 2003. ch. 3, s.3.5.1, footnote 9, on the rounded kilojoule values. https://www.fao.org/4/y5022e/y5022e04.htm.
  15. Food and Agriculture Organization of the United Nations. Food energy — methods of analysis and conversion factors. 2003. ch. 3, s.3.5.1, the Atwater general factor system, on what the factors correct for. https://www.fao.org/4/y5022e/y5022e04.htm.
  16. Food and Agriculture Organization of the United Nations. Food energy — methods of analysis and conversion factors. 2003. ch. 3, s.3.2, on why not all combustible energy is available. https://www.fao.org/4/y5022e/y5022e04.htm.
  17. Food and Agriculture Organization of the United Nations. Food energy — methods of analysis and conversion factors. 2003. ch. 3, s.3.2, the next sentence but one. https://www.fao.org/4/y5022e/y5022e04.htm.
  18. Hall, Kevin D. What is the required energy deficit per unit weight loss?. PMID 17848938, PMC2376744 (NIH author manuscript NIHMS47767). Quoted from the author manuscript. Opening paragraphs, on the energy densities of glycogen, protein and fat. https://pmc.ncbi.nlm.nih.gov/articles/PMC2376744/ (accessed 2026-09-23).
  19. Hall, Kevin D. What is the required energy deficit per unit weight loss?. PMID 17848938, PMC2376744 (NIH author manuscript NIHMS47767). Quoted from the author manuscript. Introduction, on the origin of the classic weight-loss rule. https://pmc.ncbi.nlm.nih.gov/articles/PMC2376744/ (accessed 2026-09-23).
  20. Hall, Kevin D. What is the required energy deficit per unit weight loss?. PMID 17848938, PMC2376744 (NIH author manuscript NIHMS47767). Quoted from the author manuscript. Energy density of fat mass change against adipose tissue, on why the change in body fat is not the loss of adipose tissue. https://pmc.ncbi.nlm.nih.gov/articles/PMC2376744/ (accessed 2026-09-23).
  21. Hall, Kevin D. What is the required energy deficit per unit weight loss?. PMID 17848938, PMC2376744 (NIH author manuscript NIHMS47767). Quoted from the author manuscript. Introduction, opening sentence stating the classic rule. https://pmc.ncbi.nlm.nih.gov/articles/PMC2376744/ (accessed 2026-09-23).
  22. Hall, Kevin D. What is the required energy deficit per unit weight loss?. PMID 17848938, PMC2376744 (NIH author manuscript NIHMS47767). Quoted from the author manuscript. Glycogen, protein and water, closing sentence of that section. https://pmc.ncbi.nlm.nih.gov/articles/PMC2376744/ (accessed 2026-09-23).
  23. Hall, Kevin D. What is the required energy deficit per unit weight loss?. PMID 17848938, PMC2376744 (NIH author manuscript NIHMS47767). Quoted from the author manuscript. Energy density of lean mass change, on why it is not lean tissue as a whole. https://pmc.ncbi.nlm.nih.gov/articles/PMC2376744/ (accessed 2026-09-23).
  24. Hall, Kevin D. What is the required energy deficit per unit weight loss?. PMID 17848938, PMC2376744 (NIH author manuscript NIHMS47767). Quoted from the author manuscript. Introduction, the sentence after the origin of the rule. https://pmc.ncbi.nlm.nih.gov/articles/PMC2376744/ (accessed 2026-09-23).
  25. Hall, Kevin D. What is the required energy deficit per unit weight loss?. PMID 17848938, PMC2376744 (NIH author manuscript NIHMS47767). Quoted from the author manuscript. Abstract, closing sentence, on where the rule fits the data. https://pmc.ncbi.nlm.nih.gov/articles/PMC2376744/ (accessed 2026-09-23).
  26. Bureau International des Poids et Mesures. The International System of Units (SI): Prefixes. The table of SI prefixes, as extended by CGPM Resolution 3 (2022). The SI prefixes table. BIPM. https://www.bipm.org/en/measurement-units/si-prefixes (accessed 2026-09-23).
  27. National Institute of Standards and Technology. Guide for the Use of the International System of Units (SI), NIST Special Publication 811, Footnotes. Page updated 18 August 2025. Carries the exact definitions of the thermochemical and International Table calorie. Footnotes, the paragraph fixing the thermochemical calorie. NIST. https://www.nist.gov/pml/special-publication-811/nist-guide-si-footnotes (accessed 2026-09-22).
  28. FAO/WHO/UNU. Human energy requirements. 2004. Chapter 2 page, glossary, physical activity level. https://www.fao.org/4/y5686e/y5686e00.htm (accessed 2026-09-23).
  29. FAO/WHO/UNU. Human energy requirements. 2004. Chapter 2 page, glossary, basal metabolic rate. https://www.fao.org/4/y5686e/y5686e00.htm (accessed 2026-09-23).
  30. FAO/WHO/UNU. Human energy requirements. 2004. Chapter 5 page, PAL, the worked example under Table 5.1, sedentary or light activity. https://www.fao.org/4/y5686e/y5686e00.htm (accessed 2026-09-23).
  31. FAO/WHO/UNU. Human energy requirements. 2004. Chapter 5 page, PAL, the worked example under Table 5.1, active or moderately active. https://www.fao.org/4/y5686e/y5686e00.htm (accessed 2026-09-23).
  32. FAO/WHO/UNU. Human energy requirements. 2004. Chapter 5 page, PAL, the worked example under Table 5.1, vigorous or vigorously active. https://www.fao.org/4/y5686e/y5686e00.htm (accessed 2026-09-23).
  33. FAO/WHO/UNU. Human energy requirements. 2004. Chapter 2 page, glossary, doubly labelled water. https://www.fao.org/4/y5686e/y5686e00.htm (accessed 2026-09-23).
  34. ICMR-National Institute of Nutrition. A Brief Note on Nutrient Requirements for Indians, the Recommended Dietary Allowances (RDA) and the Estimated Average Requirements (EAR). ICMR-NIN’s summary of its 2020 report, not the full report. Energy method and adult energy requirement tables quoted. Table 1a, Adult Men rows. https://www.nin.res.in/rdabook/brief_note.pdf (accessed 2026-09-23).
  35. ICMR-National Institute of Nutrition. A Brief Note on Nutrient Requirements for Indians, the Recommended Dietary Allowances (RDA) and the Estimated Average Requirements (EAR). ICMR-NIN’s summary of its 2020 report, not the full report. Energy method and adult energy requirement tables quoted. Table 1a, Adult Women rows. https://www.nin.res.in/rdabook/brief_note.pdf (accessed 2026-09-23).
  36. ICMR-National Institute of Nutrition. A Brief Note on Nutrient Requirements for Indians, the Recommended Dietary Allowances (RDA) and the Estimated Average Requirements (EAR). ICMR-NIN’s summary of its 2020 report, not the full report. Energy method and adult energy requirement tables quoted. Table 1b, adult rows (body weight kg, kcal/d, kcal/kg/day). https://www.nin.res.in/rdabook/brief_note.pdf (accessed 2026-09-23).
  37. ICMR-National Institute of Nutrition. A Brief Note on Nutrient Requirements for Indians, the Recommended Dietary Allowances (RDA) and the Estimated Average Requirements (EAR). ICMR-NIN’s summary of its 2020 report, not the full report. Energy method and adult energy requirement tables quoted. Table 1b, footnote *. https://www.nin.res.in/rdabook/brief_note.pdf (accessed 2026-09-23).
  38. ICMR-National Institute of Nutrition. A Brief Note on Nutrient Requirements for Indians, the Recommended Dietary Allowances (RDA) and the Estimated Average Requirements (EAR). ICMR-NIN’s summary of its 2020 report, not the full report. Energy method and adult energy requirement tables quoted. Recommendation on energy requirement, opening sentence. https://www.nin.res.in/rdabook/brief_note.pdf (accessed 2026-09-23).
  39. ICMR-National Institute of Nutrition. A Brief Note on Nutrient Requirements for Indians, the Recommended Dietary Allowances (RDA) and the Estimated Average Requirements (EAR). ICMR-NIN’s summary of its 2020 report, not the full report. Energy method and adult energy requirement tables quoted. Recommendation on energy requirement, physical activity level paragraph. https://www.nin.res.in/rdabook/brief_note.pdf (accessed 2026-09-23).
  40. ICMR-National Institute of Nutrition. A Brief Note on Nutrient Requirements for Indians, the Recommended Dietary Allowances (RDA) and the Estimated Average Requirements (EAR). ICMR-NIN’s summary of its 2020 report, not the full report. Energy method and adult energy requirement tables quoted. Recommendation on energy requirement, BMR paragraph. https://www.nin.res.in/rdabook/brief_note.pdf (accessed 2026-09-23).
  41. National Statistics Office. Nutritional Intake in India (2022-23 & 2023-24). 2025. Chapter Two, 2.9.6.0, how household intake of energy is calculated. https://www.mospi.gov.in/sites/default/files/publication_reports/Nutritional_Intake_in_India_L.pdf (accessed 2026-09-23).
  42. National Statistics Office. Nutritional Intake in India (2022-23 & 2023-24). 2025. Chapter Two, 2.9.6.0, what the conversion table gives, and the caution. https://www.mospi.gov.in/sites/default/files/publication_reports/Nutritional_Intake_in_India_L.pdf (accessed 2026-09-23).
  43. National Statistics Office. Nutritional Intake in India (2022-23 & 2023-24). 2025. Table 3.1, All-India row, 2023-24. https://www.mospi.gov.in/sites/default/files/publication_reports/Nutritional_Intake_in_India_L.pdf (accessed 2026-09-23).
  44. National Statistics Office. Nutritional Intake in India (2022-23 & 2023-24). 2025. Chapter Three, 3.1.1.0, per consumer unit against per capita. https://www.mospi.gov.in/sites/default/files/publication_reports/Nutritional_Intake_in_India_L.pdf (accessed 2026-09-23).
  45. Polidori, David and Sanghvi, Arjun and Seeley, Randy J and Hall, Kevin D. How strongly does appetite counter weight loss? Quantification of the feedback control of human energy intake. 2016. Introduction, on self-reported intake. https://pmc.ncbi.nlm.nih.gov/articles/PMC5108589/ (accessed 2026-09-23).
  46. Betts, J. Gordon and Young, Kelly A. and Wise, James A. and Johnson, Eddie and Poe, Brandon and Kruse, Dean H. and Korol, Oksana and Johnson, Jody E. and Womble, Mark and DeSaix, Peter. Anatomy and Physiology 2e. 2022. § 24.6 Energy and Heat Balance, the metabolic rate paragraph. https://openstax.org/books/anatomy-and-physiology-2e (accessed 2026-09-23).
  47. FAO/WHO/UNU. Human energy requirements. 2004. Chapter 2 page, components of energy requirements, basal metabolism. https://www.fao.org/4/y5686e/y5686e00.htm (accessed 2026-09-23).
  48. FAO/WHO/UNU. Human energy requirements. 2004. Chapter 2 page, components of energy requirements, metabolic response to food. https://www.fao.org/4/y5686e/y5686e00.htm (accessed 2026-09-23).
  49. FAO/WHO/UNU. Human energy requirements. 2004. Chapter 2 page, components of energy requirements, physical activity. https://www.fao.org/4/y5686e/y5686e00.htm (accessed 2026-09-23).
  50. Hall, Kevin D and Guo, Juen. Obesity energetics: body weight regulation and the effects of diet composition. PMID 28193517, PMC5568065 (NIH author manuscript). Quoted from the author manuscript text. Components of Daily Energy Expenditure, Thermic Effect of Food paragraph. https://pmc.ncbi.nlm.nih.gov/articles/PMC5568065/ (accessed 2026-09-23).
  51. Hall, Kevin D and Guo, Juen. Obesity energetics: body weight regulation and the effects of diet composition. PMID 28193517, PMC5568065 (NIH author manuscript). Quoted from the author manuscript text. Components of Daily Energy Expenditure, Resting Energy Expenditure paragraph. https://pmc.ncbi.nlm.nih.gov/articles/PMC5568065/ (accessed 2026-09-23).
  52. Hall, Kevin D and Guo, Juen. Obesity energetics: body weight regulation and the effects of diet composition. PMID 28193517, PMC5568065 (NIH author manuscript). Quoted from the author manuscript text. Components of Daily Energy Expenditure, Physical Activity Expenditure paragraph. https://pmc.ncbi.nlm.nih.gov/articles/PMC5568065/ (accessed 2026-09-23).
  53. Hall, Kevin D and Guo, Juen. Obesity energetics: body weight regulation and the effects of diet composition. PMID 28193517, PMC5568065 (NIH author manuscript). Quoted from the author manuscript text. Components of Daily Energy Expenditure, Physical Activity Expenditure paragraph, on weight loss. https://pmc.ncbi.nlm.nih.gov/articles/PMC5568065/ (accessed 2026-09-23).
  54. Betts, J. Gordon and Young, Kelly A. and Wise, James A. and Johnson, Eddie and Poe, Brandon and Kruse, Dean H. and Korol, Oksana and Johnson, Jody E. and Womble, Mark and DeSaix, Peter. Anatomy and Physiology 2e. 2022. § 24.1 Overview of Metabolic Reactions, the paragraph on catabolic and anabolic balance. https://openstax.org/books/anatomy-and-physiology-2e (accessed 2026-09-23).
  55. Flowers, Paul and Theopold, Klaus and Langley, Richard and Robinson, William R. Chemistry 2e. 2019. § 5.1 Energy Basics, the paragraph naming the law of conservation of energy. https://openstax.org/books/chemistry-2e (accessed 2026-09-23).
  56. Hall, Kevin D and Guo, Juen. Obesity energetics: body weight regulation and the effects of diet composition. PMID 28193517, PMC5568065 (NIH author manuscript). Quoted from the author manuscript text. opening paragraphs, the sentence introducing the energy-balance framework. https://pmc.ncbi.nlm.nih.gov/articles/PMC5568065/ (accessed 2026-09-23).
  57. Hall, Kevin D and Guo, Juen. Obesity energetics: body weight regulation and the effects of diet composition. PMID 28193517, PMC5568065 (NIH author manuscript). Quoted from the author manuscript text. opening paragraphs, the two sentences on energy balance and causal explanation. https://pmc.ncbi.nlm.nih.gov/articles/PMC5568065/ (accessed 2026-09-23).
  58. Thomas, Diana M and Martin, Corby K and Lettieri, Steven and Bredlau, Carl and Kaiser, Kathryn and Church, Timothy and Bouchard, Claude and Heymsfield, Steven B. Can a weight loss of one pound a week be achieved with a 3500-kcal deficit? Commentary on a commonly accepted rule. 2013. Introduction, first paragraph. https://pmc.ncbi.nlm.nih.gov/articles/PMC4024447/ (accessed 2026-09-23).
  59. Hall, Kevin D and Sacks, Gary and Chandramohan, Dhruva and Chow, Carson C and Wang, Y Claire and Gortmaker, Steven L and Swinburn, Boyd A. Quantification of the effect of energy imbalance on bodyweight. PMID 21872751, PMC3880593 (NIH author manuscript). Quoted from the author manuscript text. Introduction, second paragraph. https://pmc.ncbi.nlm.nih.gov/articles/PMC3880593/ (accessed 2026-09-23).
  60. Hall, Kevin D. What is the required energy deficit per unit weight loss?. PMID 17848938, PMC2376744 (NIH author manuscript NIHMS47767). Quoted from the author manuscript. Opening paragraph. https://pmc.ncbi.nlm.nih.gov/articles/PMC2376744/ (accessed 2026-09-23).
  61. Betts, J. Gordon and Young, Kelly A. and Wise, James A. and Johnson, Eddie and Poe, Brandon and Kruse, Dean H. and Korol, Oksana and Johnson, Jody E. and Womble, Mark and DeSaix, Peter. Anatomy and Physiology 2e. 2022. § 24.7 Nutrition and Diet, the paragraph stating the calorie rule. https://openstax.org/books/anatomy-and-physiology-2e (accessed 2026-09-23).
  62. Thomas, Diana M and Martin, Corby K and Lettieri, Steven and Bredlau, Carl and Kaiser, Kathryn and Church, Timothy and Bouchard, Claude and Heymsfield, Steven B. Can a weight loss of one pound a week be achieved with a 3500-kcal deficit? Commentary on a commonly accepted rule. 2013. figures quoted in the text. https://pmc.ncbi.nlm.nih.gov/articles/PMC4024447/ (accessed 2026-09-23).
  63. Hall, Kevin D and Sacks, Gary and Chandramohan, Dhruva and Chow, Carson C and Wang, Y Claire and Gortmaker, Steven L and Swinburn, Boyd A. Quantification of the effect of energy imbalance on bodyweight. PMID 21872751, PMC3880593 (NIH author manuscript). Quoted from the author manuscript text. figures quoted in the text. https://pmc.ncbi.nlm.nih.gov/articles/PMC3880593/ (accessed 2026-09-23).
  64. Hall, Kevin D. What is the required energy deficit per unit weight loss?. PMID 17848938, PMC2376744 (NIH author manuscript NIHMS47767). Quoted from the author manuscript. figures quoted in the text. https://pmc.ncbi.nlm.nih.gov/articles/PMC2376744/ (accessed 2026-09-23).
  65. Urone, Paul Peter and Hinrichs, Roger. College Physics 2e. 2022. § 7.6 Conservation of Energy, the law as printed under the heading Law of Conservation of Energy. https://openstax.org/books/college-physics-2e (accessed 2026-09-23).
  66. Hall, Kevin D and Sacks, Gary and Chandramohan, Dhruva and Chow, Carson C and Wang, Y Claire and Gortmaker, Steven L and Swinburn, Boyd A. Quantification of the effect of energy imbalance on bodyweight. PMID 21872751, PMC3880593 (NIH author manuscript). Quoted from the author manuscript text. Panel, “Does diet composition matter?”, first paragraph. https://pmc.ncbi.nlm.nih.gov/articles/PMC3880593/ (accessed 2026-09-23).
  67. Hall, Kevin D and Sacks, Gary and Chandramohan, Dhruva and Chow, Carson C and Wang, Y Claire and Gortmaker, Steven L and Swinburn, Boyd A. Quantification of the effect of energy imbalance on bodyweight. PMID 21872751, PMC3880593 (NIH author manuscript). Quoted from the author manuscript text. Panel, “Does diet composition matter?”, first paragraph, the sentence after the one above. https://pmc.ncbi.nlm.nih.gov/articles/PMC3880593/ (accessed 2026-09-23).
  68. Hall, Kevin D. What is the required energy deficit per unit weight loss?. PMID 17848938, PMC2376744 (NIH author manuscript NIHMS47767). Quoted from the author manuscript. Opening paragraphs, the sentence before the energy densities. https://pmc.ncbi.nlm.nih.gov/articles/PMC2376744/ (accessed 2026-09-23).
  69. Hall, Kevin D. What is the required energy deficit per unit weight loss?. PMID 17848938, PMC2376744 (NIH author manuscript NIHMS47767). Quoted from the author manuscript. Glycogen, protein and water, first paragraph. https://pmc.ncbi.nlm.nih.gov/articles/PMC2376744/ (accessed 2026-09-23).
  70. Federal Trade Commission. Gut Check: A Reference Guide for Media on Spotting False Weight Loss Claims. 2014. The 7 Gut Check Claims, Claim 1 and its explanation. US Federal Trade Commission, business guidance. https://www.ftc.gov/business-guidance/resources/gut-check-reference-guide-media-spotting-false-weight-loss-claims (accessed 2026-09-23).
  71. Federal Trade Commission. Gut Check: A Reference Guide for Media on Spotting False Weight Loss Claims. 2014. Claim #7, the explanation. US Federal Trade Commission, business guidance. https://www.ftc.gov/business-guidance/resources/gut-check-reference-guide-media-spotting-false-weight-loss-claims (accessed 2026-09-23).
  72. FAO/WHO/UNU. Human energy requirements. 2004. Chapter 5 page, Table 5.2 (Schofield BMR equations), Males, rows 18-30 and 30-60; kcal/day column, kg = body weight. https://www.fao.org/4/y5686e/y5686e00.htm (accessed 2026-09-23).
  73. FAO/WHO/UNU. Human energy requirements. 2004. Chapter 5 page, Table 5.2 (Schofield BMR equations), Females, rows 18-30 and 30-60; kcal/day column, kg = body weight. https://www.fao.org/4/y5686e/y5686e00.htm (accessed 2026-09-23).
  74. Federal Trade Commission. Gut Check: A Reference Guide for Media on Spotting False Weight Loss Claims. 2014. figures quoted in the text. US Federal Trade Commission, business guidance. https://www.ftc.gov/business-guidance/resources/gut-check-reference-guide-media-spotting-false-weight-loss-claims (accessed 2026-09-23).
  75. FAO/WHO/UNU. Human energy requirements. 2004. figures quoted in the text. https://www.fao.org/4/y5686e/y5686e00.htm (accessed 2026-09-23).
  76. Rosenbaum, Michael and Leibel, Rudolph L. Adaptive thermogenesis in humans. PMID 20935667, PMC3673773 (NIH author manuscript). Quoted from the author manuscript text. Metabolic responses to attempts to sustain weight loss: Energy expenditure, first paragraph. https://pmc.ncbi.nlm.nih.gov/articles/PMC3673773/ (accessed 2026-09-23).
  77. Polidori, David and Sanghvi, Arjun and Seeley, Randy J and Hall, Kevin D. How strongly does appetite counter weight loss? Quantification of the feedback control of human energy intake. 2016. Abstract, Results sentence. https://pmc.ncbi.nlm.nih.gov/articles/PMC5108589/ (accessed 2026-09-23).
  78. Polidori, David and Sanghvi, Arjun and Seeley, Randy J and Hall, Kevin D. How strongly does appetite counter weight loss? Quantification of the feedback control of human energy intake. 2016. Results, paragraph on the strength of energy intake feedback control. https://pmc.ncbi.nlm.nih.gov/articles/PMC5108589/ (accessed 2026-09-23).
  79. Polidori, David and Sanghvi, Arjun and Seeley, Randy J and Hall, Kevin D. How strongly does appetite counter weight loss? Quantification of the feedback control of human energy intake. 2016. Discussion, limitations paragraph. https://pmc.ncbi.nlm.nih.gov/articles/PMC5108589/ (accessed 2026-09-23).
  80. Polidori, David and Sanghvi, Arjun and Seeley, Randy J and Hall, Kevin D. How strongly does appetite counter weight loss? Quantification of the feedback control of human energy intake. 2016. Discussion, limitations paragraph on group means. https://pmc.ncbi.nlm.nih.gov/articles/PMC5108589/ (accessed 2026-09-23).
  81. Polidori, David and Sanghvi, Arjun and Seeley, Randy J and Hall, Kevin D. How strongly does appetite counter weight loss? Quantification of the feedback control of human energy intake. 2016. Results, paragraph on the trial’s weight and energy intake changes. https://pmc.ncbi.nlm.nih.gov/articles/PMC5108589/ (accessed 2026-09-23).
  82. Polidori, David and Sanghvi, Arjun and Seeley, Randy J and Hall, Kevin D. How strongly does appetite counter weight loss? Quantification of the feedback control of human energy intake. 2016. Discussion, paragraph on the range of weight losses. https://pmc.ncbi.nlm.nih.gov/articles/PMC5108589/ (accessed 2026-09-23).
  83. Polidori, David and Sanghvi, Arjun and Seeley, Randy J and Hall, Kevin D. How strongly does appetite counter weight loss? Quantification of the feedback control of human energy intake. 2016. Introduction, paragraph on self-reported intake. https://pmc.ncbi.nlm.nih.gov/articles/PMC5108589/ (accessed 2026-09-23).
  84. Hall, Kevin D and Guo, Juen. Obesity energetics: body weight regulation and the effects of diet composition. PMID 28193517, PMC5568065 (NIH author manuscript). Quoted from the author manuscript text. Opening paragraphs, third paragraph. https://pmc.ncbi.nlm.nih.gov/articles/PMC5568065/ (accessed 2026-09-23).
  85. Hall, Kevin D and Guo, Juen. Obesity energetics: body weight regulation and the effects of diet composition. PMID 28193517, PMC5568065 (NIH author manuscript). Quoted from the author manuscript text. Static, Settling Point, and Set-Point Models, first paragraph. https://pmc.ncbi.nlm.nih.gov/articles/PMC5568065/ (accessed 2026-09-23).
  86. Hall, Kevin D and Guo, Juen. Obesity energetics: body weight regulation and the effects of diet composition. PMID 28193517, PMC5568065 (NIH author manuscript). Quoted from the author manuscript text. Influence of Energy Intake on Energy Expenditure, first paragraph. https://pmc.ncbi.nlm.nih.gov/articles/PMC5568065/ (accessed 2026-09-23).
  87. Hall, Kevin D and Guo, Juen. Obesity energetics: body weight regulation and the effects of diet composition. PMID 28193517, PMC5568065 (NIH author manuscript). Quoted from the author manuscript text. Feedback Control of Energy Intake, last paragraph. https://pmc.ncbi.nlm.nih.gov/articles/PMC5568065/ (accessed 2026-09-23).
  88. Hall, Kevin D and Guo, Juen. Obesity energetics: body weight regulation and the effects of diet composition. PMID 28193517, PMC5568065 (NIH author manuscript). Quoted from the author manuscript text. Static, Settling Point, and Set-Point Models, closing paragraph. https://pmc.ncbi.nlm.nih.gov/articles/PMC5568065/ (accessed 2026-09-23).
  89. Rosenbaum, Michael and Leibel, Rudolph L. Adaptive thermogenesis in humans. PMID 20935667, PMC3673773 (NIH author manuscript). Quoted from the author manuscript text. figures quoted in the text. https://pmc.ncbi.nlm.nih.gov/articles/PMC3673773/ (accessed 2026-09-23).
  90. Polidori, David and Sanghvi, Arjun and Seeley, Randy J and Hall, Kevin D. How strongly does appetite counter weight loss? Quantification of the feedback control of human energy intake. 2016. figures quoted in the text. https://pmc.ncbi.nlm.nih.gov/articles/PMC5108589/ (accessed 2026-09-23).
  91. Hall, Kevin D and Guo, Juen. Obesity energetics: body weight regulation and the effects of diet composition. PMID 28193517, PMC5568065 (NIH author manuscript). Quoted from the author manuscript text. figures quoted in the text. https://pmc.ncbi.nlm.nih.gov/articles/PMC5568065/ (accessed 2026-09-23).
  92. Flowers, Paul and Theopold, Klaus and Langley, Richard and Robinson, William R. Chemistry 2e. 2019. 5.1 Energy Basics, paragraph on the law of conservation of energy. https://openstax.org/books/chemistry-2e (accessed 2026-09-23).
  93. Hall, Kevin D and Guo, Juen. Obesity energetics: body weight regulation and the effects of diet composition. PMID 28193517, PMC5568065 (NIH author manuscript). Quoted from the author manuscript text. Opening paragraphs, second and third paragraphs. https://pmc.ncbi.nlm.nih.gov/articles/PMC5568065/ (accessed 2026-09-23).
  94. Hall, Kevin D and Guo, Juen. Obesity energetics: body weight regulation and the effects of diet composition. PMID 28193517, PMC5568065 (NIH author manuscript). Quoted from the author manuscript text. Opening paragraphs, third paragraph, opening sentence. https://pmc.ncbi.nlm.nih.gov/articles/PMC5568065/ (accessed 2026-09-23).
  95. Polidori, David and Sanghvi, Arjun and Seeley, Randy J and Hall, Kevin D. How strongly does appetite counter weight loss? Quantification of the feedback control of human energy intake. 2016. Discussion, summary paragraph. https://pmc.ncbi.nlm.nih.gov/articles/PMC5108589/ (accessed 2026-09-23).