Science has discovered that physiological responses to weight loss trigger weight regain1-5

Weight loss in people with obesity causes changes in appetite hormones that increase hunger and the desire to eat for at least 1 year1

Multiple hormones, such as ghrelin, GLP-1, and leptin, play an important role in appetite regulation.6 

Mary, with BMI of 44, is struggling with weight regain


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  1. Sumithran P, Prendergast LA, Delbridge E, et al. Long-term persistence of hormonal adaptations to weight loss. N Engl J Med. 2011;365(17):1597-1604.
  2. Schwartz A, Doucet É. Relative changes in resting energy expenditure during weight loss: a systematic review. Obes Rev. 2010;11(7):531-547.
  3. Sumithran P, Proietto J. The defence of body weight: a physiological basis for weight regain after weight loss. Clin Sci (Lond). 2013;124(4):231-241.
  4. Rosenbaum M, Leibel RL. Adaptive thermogenesis in humans. Int J Obes (Lond). 2010;34(suppl 1):S47-S55.
  5. Rosenbaum M, Kissileff HR, Mayer LE, Hirsch J, Leibel RL. Energy intake in weight-reduced humans. Brain Res. 2010;1350:95-102.
  6. Badman MK, Flier JS. The gut and energy balance: visceral allies in the obesity wars. Science. 2005;307(5717):1909-1914.