***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND Although dietary restriction often results in initial weight loss , the majority of obese dieters fail to maintain their reduced weight . Diet-induced weight loss results in compensatory increase of hunger , craving and decreased ghrelin suppression that encourage weight regain . A high protein and carbohydrate breakfast may overcome these compensatory changes and prevent obesity relapse . METHODS In this study 193 obese ( BMI 32.2±1.0kg/m(2 ) ) , sedentary non diabetic adult men and women ( 47±7years ) were r and omized to a low carbohydrate breakfast ( LCb ) or an isocaloric diet with high carbohydrate and protein breakfast ( HCPb )  . Anthropometric measures were assessed every 4weeks . Fasting glucose , insulin , ghrelin , lipids , craving scores and breakfast meal challenge assessing hunger , satiety , insulin and ghrelin responses , were performed at baseline , after a Diet Intervention Period ( Week 16 ) and after a Follow-up Period ( Week 32 ) . RESULTS At Week 16 , groups exhibited similar weight loss : 15.1±1.9 kg in LCb group vs. 13.5±2.3 kg in HCPb group , p=0.11 . From Week 16 to Week 32 , LCb group regained 11.6±2.6 kg , while the HCPb group lost additional 6.9±1.7 kg . Ghrelin levels were reduced after breakfast by 45.2 % and 29.5 % following the HCPb and LCb , respectively . Satiety was significantly improved and hunger and craving scores significantly reduced in the HCPb group vs. the LCb group . CONCLUSION A high carbohydrate and protein breakfast may prevent weight regain by reducing diet-induced compensatory changes in hunger , cravings and ghrelin suppression . To achieve long-term weight loss , meal timing and macronutrient composition must counteract these compensatory mechanisms which encourage weight regain after weight loss BACKGROUND Energy or calorie restriction ( CR ) has consistently been shown to produce weight loss and have beneficial health effects in numerous species , including primates and humans . Most individuals , however , are unable to sustain weight losses induced through reductions in energy intake , potentially due to increased hunger levels . The effects that prolonged CR has on subjective aspects of appetite have not been well studied . Thus , the present study tested the effect of 6 months of caloric restriction on appetite in healthy , overweight men and women . METHODS Forty-eight overweight men and women with a body mass index ( BMI ; kg m(-2 ) ) between 25 - 29.9 took part in a 6-month study and were r and omised into one of four groups : healthy diet ( control ) ; 25 % CR ; 12.5 % CR plus exercise ( 12.5 % increased energy expenditure ; CR + EX ) ; low-calorie diet [ LCD ; 3724 kJ day(-1 ) ( 890 kcal day(-1 ) ) until 15 % of initial body weight was lost , then maintenance ] . Appetite markers ( i.e. hunger , fullness , desire to eat , etc . ) were assessed weekly during a fasting state . RESULTS Body weight was significantly reduced in all three energy-restricted groups ( CR = -10.4 + /- 0.9 % ; CR + EX = -10.0 + /- 0.8 % ; and LCD = -13.9 + /-0.7 % ) , indicating that participants were adherent to their energy restriction regimen , whereas the healthy diet control group remained weight stable ( control = -1.0 + /- 1.1 % ) . Despite these significant weight losses , appetite ratings of participants in the three energy-restricted groups at month 6 were similar to the weight stable control group . CONCLUSIONS CR regimens with low fat diets producing significant weight losses have similar effects on appetite markers over a 6-month time period compared to a weight stable control group Few well-controlled trials have evaluated the effects that macronutrient composition has on changes in food cravings during weight loss treatment . The present study , which was part of the Preventing Overweight Using Novel Dietary Strategies ( POUNDS LOST ) trial , investigated whether the fat and protein content of four different diets affected changes in specific food cravings in overweight and obese adults . A sample of 811 adults were recruited across two clinical sites , and each participant was r and omly assigned to one of four macronutrient prescriptions : 1 ) low fat ( 20 % of energy ) , average protein ( 15 % of energy ) ; 2 ) moderate fat ( 40 % ) , average protein ( 15 % ) ; 3 ) low fat ( 20 % ) , high protein ( 25 % ) ; 4 ) moderate fat ( 40 % ) , high protein ( 25 % ) . With few exceptions , the type of diet that participants were assigned did not differentially affect changes in specific food cravings . Participants assigned to the high-fat diets , however , had reduced cravings for carbohydrates at month 12 ( p<0.05 ) and fruits and vegetables at month 24 . Also , participants assigned to high-protein diets had increased cravings for sweets at month 6 and month 12 ( ps<0.05 ) . Participants in all four dietary conditions reported significant reductions in food cravings for specific types of foods ( i.e. , high fat foods , fast food fats , sweets , and carbohydrates/starches ; all ps<0.05 ) . Cravings for fruits and vegetables , however , were increased at month 24 ( p<0.05 ) . Calorically restricted diets ( regardless of their macronutrient composition ) yielded significant reductions in cravings for fats , sweets , and starches whereas cravings for fruits and vegetables were increased Behavioral studies have suggested that food cues have stronger motivating effects in obese than in normal-weight individuals , which may be a risk factor underlying obesity . Previous cross-sectional neuroimaging studies have suggested that this difference is mediated by increased reactivity to food cues in parts of the reward system in obese individuals . To date , however , only a few prospect i ve neuroimaging studies have been conducted to examine whether individual differences in brain activation elicited by food cues can predict differences in weight change . We used functional magnetic resonance imaging ( fMRI ) to investigate activation in reward-system as well as other brain regions in response to viewing high-calorie food vs. control pictures in 25 obese individuals before and after a 12-week psychosocial weight-loss treatment  and at 9-mo follow-up . In those obese individuals who were least successful in losing weight during the treatment , we found greater pre-treatment activation to high-calorie food vs. control pictures in brain regions implicated in reward-system processes , such as the nucleus accumbens , anterior cingulate , and insula . We found similar correlations with weight loss in brain regions implicated by other studies in vision and attention , such as superior occipital cortex , inferior and superior parietal lobule , and prefrontal cortex . Furthermore , less successful weight maintenance at 9-mo follow-up was predicted by greater post-treatment activation in such brain regions as insula , ventral tegmental area , putamen , and fusiform gyrus . In summary , we found that greater activation in brain regions mediating motivational and attentional salience of food cues in obese individuals at the start of a weight-loss program was predictive of less success in the program and that such activation following the program predicted poorer weight control over a 9-mo follow-up period Objective Very-low-calorie diets have been shown to produce dramatic improvements in glycemic control in obese subjects with non-insulin-dependent ( type II ) diabetes . There have been no studies of the psychological responses of diabetic subjects to these diets . Research Design and Methods This study examined changes in hunger , depression , and anxiety in 33 obese type II diabetic subjects who were r and omly assigned to behavior modification programs that used either a balanced diet of 4185–6277 J∕day ( 1000–1500 cal∕day ) throughout or included an 8-wk period of a very-low-calorie diet ( 1674 J∕day or 400 cal∕day of lean meat , fish , or fowl ) . Subjects completed the Beck Depression Inventory , the Spielberger State Anxiety Question naire , and self-report measures of hunger frequently throughout the 20-wk program . Results Both groups experienced significant improvements in depressive symptomatology , anxiety , and lessening of hunger during the course of the program , with no significant differences observed between the balanced diet and the very-low-calorie diet groups . Conclusions Very-low-calorie diets , used in the context of a behavioral weight-control program , result in reductions in hunger and improvements in mood state comparable to those observed on more moderate weight-loss regimens Objective Few studies have examined brain changes in response to effective weight loss ; none have compared different methods of weight-loss intervention . We compared functional brain changes associated with a behavioral weight loss intervention to those associated with bariatric surgery . Methods 15 obese participants were recruited prior to adjustable gastric b and ing surgery and 16 obese participants were recruited prior to a behavioral diet intervention .  Groups were matched for demographics and amount of weight lost . fMRI scans ( visual food motivation paradigm while hungry and following a meal ) were conducted before , and 12 weeks after surgery/behavioral intervention . Results When compared to bariatric patients in the pre-meal analyses , behavioral dieters showed increased activation to food images in right medial PFC and left precuneus following weight loss . When compared to behavioral dieters , bariatric patients showed increased activation in in bilateral temporal cortex following the weight loss . Conclusions Behavioral dieters showed increased responses to food cues in medial PFC – a region associated with valuation and processing of self-referent information – when compared to bariatric patients . Bariatric patients showed increased responses to food cues in brain regions associated with higher level perception — when compared to behavioral dieters . The method of weight loss determines unique changes in brain function This study compared reports of appetite and symptoms in 28 obese subjects r and omly assigned to either a 500 calorie protein-sparing modified fast ( PSMF ) or a 1200-kcal balanced diet . During the first comparison month , subjects consuming the PSMF lost significantly more weight and reported significantly less hunger than did subjects consuming the 1200 kcal diet . Similar results were obtained for the second month , but differences in hunger were not statistically significant . There were no significant differences between conditions in subjects ' ratings of their preoccupation with eating or in their ratings of the acceptability or disruptiveness of their diets . PSMF subjects reported significantly greater problems with cold intolerance , constipation , dizziness , dry skin , and fatigue . These symptoms remitted completely , however , when PSMF subjects consumed a 1200-kcal balanced diet . There were no significant differences between conditions in subjects ' reports of psychological functioning . Results are discussed in terms of the need for further research to identify the characteristics of PSMF which confer anorexia The importance of hunger state for the acquisition and expression of  chocolate craving was investigated . Seventeen chocolate cravers and 12 non-cravers were supplied with chocolate and instructed to eat some twice a day for 14 days . Within each group , subjects were allocated to one of two conditions , hungry- or full-trained . Hungry-trained subjects were asked to eat the chocolate exclusively at least 2 h after last eating ; full-trained subjects were asked only to eat the chocolate 15 - 30 min after eating a meal . A diary was kept to encourage and allow assessment of compliance . At the start and end of the 2 weeks , subjects rated their craving for and anticipated intake of chocolate prior to eating it ; then , on initial tasting , pleasantness of the taste was rated . All subjects made these ratings on one day when hungry and on another when full , as defined above . For cravers and non-cravers who ate chocolate exclusively when hungry , chocolate craving increased post-training , but , at least for cravers , only when ratings were made while hungry . For full-trained subjects , chocolate craving decreased post-training , but this decrease did not depend on whether subjects were currently hungry or full . A similar pattern of results was found for anticipated intake and pleasantness of taste , except that pleasantness did not increase in hungry-trained subjects . The results are interpreted with reference to learned control of appetite and in particular to recent findings on incentive learning processes . Craving for chocolate or other foods may be an expression of a strong appetite elicited by hunger that has been acquired by repeated experience of eating the craved food when hungry We examined the association of food cravings with weight loss and eating behaviors in a lifestyle intervention for weight loss in worksites . This research was part of a r and omized controlled trial of a 6-month weight loss intervention versus a wait-listed control in 4 Massachusetts worksites . The intervention emphasized reducing energy intake by adherence to portion-controlled menu suggestions , and assessment s were obtained in 95 participants at baseline and 6 months including non-fasting body weight , food cravings ( Craving Inventory and Food Craving Question naire for state and trait ) and the eating behavior constructs restraint , disinhibition and hunger ( Eating Inventory ) . There were statistically significant reductions in all craving variables in the intervention group compared to the controls . Within the intervention group , changes in craving-trait were significantly associated with weight loss after controlling for baseline weight , age , gender and worksite . However , in a multivariate model with craving-trait and eating behaviors ( restraint , disinhibition and hunger ) , hunger was the only significant predictor of weight change . In contrast to some previous reports of increased food cravings with 
    Output:
    
CONCLUSIONS Calorie restriction is associated with reduced food cravings supporting a de-conditioning model of craving reductions .