Tuesday, July 14, 2015

Text states different facts about reduction in RMR or REE after weight loss? UPDATE JULY 14, 2015

I wrote Dr. Frank Greenway about the incongruence of the Handbook of Obesity and he updated me with more recent studies. `

"Conclusions: Despite relative preservation of FFM, exercise did not prevent dramatic slowing of resting metabolism out of proportion to weight loss. This metabolic adaptation may persist during weight maintenance and predispose to weight regain unless high levels of physical activity or caloric restriction are maintained. (J Clin Endocrinol Metab 97: 2489 –2496, 2012)"

"In conclusion, we found that an intensive lifestyle intervention consisting of daily vigorous exercise plus self-selected dietary restriction resulted in massive weight loss of similar magnitude to a matched group of subjects following gastric bypass surgery. Both groups showed significant improvements in cardio-metabolic profile and a resolution of Class III obesity. Unlike RYGB patients who lost a substantial amount of FFM, Biggest Loser Contest participants partially pre- served FFM despite rapid weight loss. However, FFM preservation did not attenuate the reduction of metabolic rate and both groups demonstrated a significant metabolic adaptation to weight loss that was correlated with the energy deficit and changes in leptin."
Obesity | VOLUME 22 | NUMBER 12 | DECEMBER 2014  p2567 Metabolic Adaptation with Massive Weight Loss Knuth et al.




4-15 Video on REE after bariatric surgery

In above video:
Dr. Dympna Gallagher shows that REE (resting energy expenditure) reduces more in weight loss than  can be explained.

To my confusion, as I study for the Obesity Boards in Dec 2015 I found this passage in the Handbook of Obesity edited by George A. Bray and Claude Bouchard Vol 2 Fourth edition on p. 442 in a chapter authored byDavid Heber and Frank L Greenway:

"Weight loss is always accompanied by a reduction in resting energy expenditure, but this decrease is proportional to the loss of lean body mass, and therefore, there is no evidence of adaptive decreases in resting metabolic rate due to surgery that could explain weight regain."

To further confound me I found this passage on p 147 in the same book in a chapter written by Steve Anton, John Froeyt, and Michael G. Perri:

"Recent findings suggest that the hormonal changes that encourage food intake following diet-induced weight loss persist and do not revert to baseline levels even after 1 year following the initial weight reduction.  Moreover, after a period of dieting,  resting metabolic rate decreases beyond the level expected from the loss of body mass alone.  see POUNDS LOST study.

References: 
de Jonge L, Bray GA, Smith, Ryan, De Souza  Effect of diet composition  and weight loss on resting energy expenditure in the POUNDS LOST STUDY Obesity 2012 (12):2384-9

My favorite video explaining why the reduced obese regain weight is this from Weight of the Nation HBO: 
Columbia University





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