You will be presented with a collection of medical randomized controlled trial (RCT) reports addressing a shared clinical question -- for instance, the efficacy of a medical intervention on a disease or condition. Given the titles and abstracts of these reports, your task is to generate the conclusion of the systematic review article synthesizing the key findings. Your conclusion should be a few sentences long. In your response, include only the conclusion and no other text. The RCT reports are below.



Title 1:
Evidence for the existence of adaptive thermogenesis during weight loss.
Abstract 1:
The present study was performed to further investigate the adaptive component of thermogenesis that appears during prolonged energy restriction . Fifteen obese men and twenty obese women underwent a 15-week weight-loss programme .  During this programme , body weight and composition as well as resting energy expenditure ( REE ) were measured at baseline , after 2 and 8 weeks of energy restriction ( -2929 kJ/d ) and drug therapy ( or placebo ) , and finally 2 - 4 weeks after the end of the 15-week drug therapy and energy restriction intervention , when subjects were weight stable . Regression equations were established in a control population of the same age . These equations were then used to predict REE in obese men and women at baseline , after 2 and 8 weeks , as well as after the completion of the programme . In both men and women body weight and fat mass were significantly reduced in all cases ) while fat-free mass remained unchanged throughout the programme . At baseline , REE predicted from the regression equation was not significantly different from the measured REE in men , while in women the measured REE was 13 % greater than predicted . After 2 weeks of energy restriction , measured REE had fallen by 469 and 635 kJ/d more than predicted and this difference reached 963 and 614 kJ/d by week 8 of treatment in men and women respectively . Once body-weight stability was recovered at the end of the programme , changes in REE remained below predicted changes in men ( -622 kJ/d ) . However , in women changes in predicted and measured REE were no longer different at this time , even if the women were maintaining a reduced body weight . In summary , the present results confirm the existence of adaptive thermogenesis and give objective measurements of this component during weight loss in obese men and women , while they also emphasize that in women this component seems to be essentially explained by the energy restriction


Title 2:
Changes in energy expenditure and substrate oxidation resulting from weight loss in obese men and women: is there an important contribution of leptin?
Abstract 2:
The aim of the present study was to determine the impact of weight loss and its related metabolic and hormonal changes on resting energy expenditure ( REE ) and substrate oxidation . Forty subjects ( 16 men and 24 women ) took part in a 15-week weight loss program that consisted of drug therapy ( fenfluramine , 60 mg/day ) or placebo coupled to an energy restriction ( -700 Cal/day ) . Subjects were asked to come to the laboratory after an overnight fast for an indirect calorimetry measurement before and after weight loss . Fasting blood sample s were also drawn and were analyzed for plasma glucose , insulin , leptin , and free fatty acid determinations . This program reduced body weight by 11 % and 9 % ( P < 0.01 ) in men and women , respectively . Fat mass ( FM ) and fat-free mass ( FFM ) were also significantly reduced in both sexes . A significant decrease in REE ( 13 % ; P < 0.01 ) and fat oxidation ( 11 % ; P = 0.08 ) was observed in men in response to this program , whereas no significant differences were noted for these variables in women . In men , positive correlations were found between changes in FFM and energy-related variables , whereas the best predictor of changes in REE and substrate oxidation was the change in FM in women . The most important finding of this study is that in men , the association between changes in fasting plasma leptin and changes in REE ( r = 0.50 ; P < 0.01 ) and fat oxidation ( r = 0.63 ; P < 0.01 ) persist after correction for changes in body composition . These results suggest that a comparable weight loss is accompanied by a greater decrease in REE and substrate oxidation in men than in women , and that these changes are better explained by changes in leptinemia in men and by changes in FM in women
This analysis does not support the notion of a greater than predicted decrease in resting EE after weight loss