title: Protein intake, weight loss, and bone mineral density in postmenopausal women. Effects of protein, monounsaturated fat, and carbohydrate intake on blood pressure and serum lipids: results of the OmniHeart randomized trial. A diet high in protein, dairy, and calcium attenuates bone loss over twelve months of weight loss and maintenance relative to a conventional high-carbohydrate diet in adults. Comparison of weight-loss diets with different compositions of fat, protein, and carbohydrates. A Low-Carbohydrate, Ketogenic Diet versus a Low-Fat Diet To Treat Obesity and Hyperlipidemia Effect of high vegetable protein diets on urinary calcium loss in middle-aged men and women Effects of different dietary protein intakes on body composition and vascular reactivity Effect of normal-fat diets, either medium or high in protein, on body weight in overweight subjects: a randomised 1-year trial Macronutrient intake, plasma large neutral amino acids and mood during weight-reducing diets Renal function following long-term weight loss in individuals with abdominal obesity on a very-low-carbohydrate diet vs high-carbohydrate diet. Diets higher in dairy foods and dietary protein support bone health during diet- and exercise-induced weight loss in overweight and obese premenopausal women. Effect of protein intake on bone mineralization during weight loss: a 6-month trial. Developing optimal search strategies for detecting clinically sound treatment studies in EMBASE. Long-term effects of a very low-carbohydrate diet and a low-fat diet on mood and cognitive function.
abstract: BACKGROUND Higher protein diets are promoted for effective weight loss . Striated tissues in omnivorous diets contain high- quality protein , but limited data exist regarding their effects on bone . METHODS To examine the effects of energy restriction-induced weight loss with higher protein omnivorous diets versus lower protein vegetarian diets on  bone mineral density  in overweight postmenopausal women , two r and omized controlled feeding studies were conducted . In Study 1 , 28 women consumed 750 kcal/day energy deficit diets with 18 % energy from protein via lacto-ovo vegetarian sources ( normal protein , n = 15 ) or 30 % energy from protein with 40 % of protein from lean pork ( higher protein , n = 13 , omnivorous ) for 12 weeks . In Study 2 , 54 women consumed their habitual diet ( control , n = 11 ) or 1,250 kcal/day diets with 16 % energy from nonmeat protein sources ( n = 14 ) or 26 % energy from protein , including chicken ( n = 15 ) or beef ( n = 14 ) for 9 weeks . RESULTS Study 1 : With weight loss ( normal protein -11.2 % , higher protein -10.1 % ) , bone mineral density was not significantly changed in normal protein ( -0.003 ± 0.003 g/cm(2 ) , -0.3 % ) but decreased in higher protein ( -0.0167 ± 0.004 g/cm(2 ) , -1 . 4 % , group-by-time p < .05 ) . Study 2 : The control , nonmeat , chicken , and beef groups lost 1.5 % , 7.7 % , 10.4 % , and 8.1 % weight and 0.0 % , 0.4 % , 1.1 % , and 1.4 % bone mineral density , respectively . The change of bone mineral density was significant for chicken and beef compared with the control ( group-by-time , p < .05 ) . Markers of calcium metabolism and bone homeostasis in blood and urine were not changed over time or differentially affected by diet . CONCLUSION Consumption of higher protein omnivorous diets promoted decreased bone mineral density after weight loss in overweight postmenopausal women CONTEXT Reduced intake of saturated fat is widely recommended for prevention of cardiovascular disease . The type of macronutrient that should replace saturated fat remains uncertain . OBJECTIVE To compare the effects of 3 healthful diets , each with reduced saturated fat intake , on blood pressure and serum lipids . DESIGN , SETTING , AND PARTICIPANTS R and omized , 3-period , crossover feeding study ( April 2003 to June 2005 ) conducted in Baltimore , Md , and Boston , Mass. Participants were 164 adults with prehypertension or stage 1 hypertension . Each feeding period lasted 6 weeks and body weight was kept constant . INTERVENTIONS A diet rich in carbohydrates ; a diet rich in protein , about half from plant sources ; and a diet rich in unsaturated fat , predominantly monounsaturated fat . MAIN OUTCOME MEASURES Systolic blood pressure and low-density lipoprotein cholesterol . RESULTS Blood pressure , low-density lipoprotein cholesterol , and estimated coronary heart disease risk were lower on each diet compared with baseline . Compared with the carbohydrate diet , the protein diet further decreased mean systolic blood pressure by 1.4 mm Hg ( P = .002 ) and by 3.5 mm Hg ( P = .006 ) among those with hypertension and decreased low-density lipoprotein cholesterol by 3.3 mg/dL ( 0.09 mmol/L ; P = .01 ) , high-density lipoprotein cholesterol by 1.3 mg/dL ( 0.03 mmol/L ; P = .02 ) , and triglycerides by 15.7 mg/dL ( 0.18 mmol/L ; P<.001 ) . Compared with the carbohydrate diet , the unsaturated fat diet decreased systolic blood pressure by 1.3 mm Hg ( P = .005 ) and by 2.9 mm Hg among those with hypertension ( P = .02 ) , had no significant effect on low-density lipoprotein cholesterol , increased high-density lipoprotein cholesterol by 1.1 mg/dL ( 0.03 mmol/L ; P = .03 ) , and lowered triglycerides by 9.6 mg/dL ( 0.11 mmol/L ; P = .02 ) . Compared with the carbohydrate diet , estimated 10-year coronary heart disease risk was lower and similar on the protein and unsaturated fat diets . CONCLUSION In the setting of a healthful diet , partial substitution of carbohydrate with either protein or monounsaturated fat can further lower blood pressure , improve lipid levels , and reduce estimated cardiovascular risk . Clinical Trials Registration Clinical Trials.gov Identifier : NCT00051350 Weight loss causes  bone mineral loss .  Higher protein diets continue to be criticized for further potential harmful bone effects , including elevated urinary calcium , but may promote bone health if protein sources include dairy . Overweight middle-aged subjects ( n = 130 , 59 males ) were r and omized to a diet providing 1.4 g.kg(-1).d(-1 ) protein and 3 daily servings of dairy ( PRO ) or 0.8 g.kg(-1).d(-1 ) protein and 2 daily servings of dairy ( CARB ) for 4 mo of weight loss plus 8 mo of weight maintenance . Diets prescribed 6276 kJ/d for females and 7113 kJ/d for males . Bone mineral content and density ( BMD ) for whole body ( WB ) , lumbar spine ( LS ) and total hip ( TH ) were measured using dual X-ray absorptiometry , and dietary intake using 3-d weighed food records . Urinary calcium was measured using 24-h collection at 0 and 8 mo for a sub sample ( n = 42 ) . Participants lost body weight ( mean , 95 % CI ) of 8.2 % ( 7.5 - 8.9 % ) at 4 mo , 10.6 % ( 9.5 - 11.8 % ) at 8 mo , and 10.5 % ( 8.9 - 12.0 % ) at 12 mo without differences between groups at any time ( P = 0.64 ) . At 12 mo , PRO BMD was higher by 1.6 % ( 0.3 - 3.0 % ) at WB , 2.1 % ( 0.6 - 3.7 % ) at LS , and 1.4 % ( 0.2 - 2.5 % ) at TH compared with  CARB  .  PRO calcium intake was higher ( PRO : 1140 + /- 58 mg/d , CARB : 766 + /- 46 ; P < 0.01 ) , as was urinary calcium ( PRO : 163 + /- 15 mg/d , CARB : 100 + /- 9.2 ; P < 0.01 ) . A reduced-energy diet supplying 1.4 g.kg(-1).d(-1 ) protein and 3 dairy servings increased urinary calcium excretion but provided improved calcium intake and attenuated bone loss over 4 mo of weight loss and 8 additional mo of weight maintenance BACKGROUND The possible advantage for weight loss of a diet that emphasizes protein , fat , or carbohydrates has not been established , and there are few studies that extend beyond 1 year . METHODS We r and omly assigned 811 overweight adults to one of four diets ; the targeted percentages of energy derived from fat , protein , and carbohydrates in the four diets were 20 , 15 , and 65 % ; 20 , 25 , and 55 % ; 40 , 15 , and 45 % ; and 40 , 25 , and 35 % . The diets consisted of similar foods and met guidelines for cardiovascular health . The participants were offered group and individual instructional sessions for 2 years . The primary outcome was the change in body weight after 2 years in two-by-two factorial comparisons of low fat versus high fat and average protein versus high protein and in the comparison of highest and lowest carbohydrate content . RESULTS At 6 months , participants assigned to each diet had lost an average of 6 kg , which represented 7 % of their initial weight ; they began to regain weight after 12 months . By 2 years , weight loss remained similar in those who were assigned to a diet with 15 % protein and those assigned to a diet with 25 % protein ( 3.0 and 3.6 kg , respectively ) ; in those assigned to a diet with 20 % fat and those assigned to a diet with 40 % fat ( 3.3 kg for both groups ) ; and in those assigned to a diet with 65 % carbohydrates and those assigned to a diet with 35 % carbohydrates ( 2.9 and 3.4 kg , respectively ) ( P>0.20 for all comparisons ) . Among the 80 % of participants who completed the trial , the average weight loss was 4 kg ; 14 to 15 % of the participants had a reduction of at least 10 % of their initial body weight . Satiety , hunger , satisfaction with the diet , and attendance at group sessions were similar for all diets ; attendance was strongly associated with weight loss ( 0.2 kg per session attended ) . The diets improved lipid-related risk factors and fasting insulin levels . CONCLUSIONS Reduced-calorie diets result in clinical ly meaningful weight loss regardless of which macronutrients they emphasize . ( Clinical Trials.gov number , NCT00072995 . Context Low-carbohydrate weight reduction diets are popular despite a dearth of data on long-term efficacy and adverse effects . Contribution Community-dwelling hyperlipidemic persons were r and omly assigned to either a low-carbohydrate , ketogenic diet or a low-fat , low-cholesterol , reduced-calorie diet for 24 weeks . Compared to the low-fat group , patients in the low-carbohydrate group lost more weight , had a greater decrease in triglyceride levels , and had higher high-density lipoprotein cholesterol levels . Levels of low-density lipoprotein cholesterol remained stable in both groups . Side effects were more common in the low-cholesterol group but were generally mild . Caution s While the study suggests the efficacy and relative safety of the low-cholesterol diet , the high dropout rate , self-directed adherence to the diet , and relatively short observation period challenge the generalizability of the findings . The Editors As the prevalence of obesity has increased over the past 20 years ( 1 ) , the difficulties faced by overweight patients and their health care practitioners have become apparent . Fewer than 25 % of Americans who attempt to lose weight actually reduce caloric intake and increase exercise as currently recommended ( 2 ) . Persons who successfully lose weight have difficulty maintaining their weight loss ( 3 ) . Therefore , it is not surprising that consumers spend $ 33 billion yearly on weight loss products and services in search of effective therapies ( 2 ) . Because many weight loss interventions are unproven and untested , practitioners often lack information with which to recommend a certain therapy or to monitor a patient once a therapy is chosen . One approach to weight loss that has gained recognition in the face of modest supportive scientific evidence is the low-carbohydrate diet . A popular version of this diet recommends extreme restriction of carbohydrate intake to less than 20 g/d initially ( 4 ) . This level of carbohydrate restriction can induce serum and urinary ketones and weight loss ( 5 , 6 ) . However , until recently , available data on low-carbohydrate diets came from small studies of short duration , most of which were uncontrolled ( 5 , 7 - 10 ) . We examined body weight , body composition , serum lipid levels , and adverse effects over 24 weeks in hyperlipidemic persons who were r and omly assigned to follow a low-carbohydrate , ketogenic diet or a low-fat , low-cholesterol , reduced-calorie diet commonly used to induce weight loss and decrease serum lipid levels . Methods Participants Generally healthy persons were recruited from the community . Inclusion criteria were age 18 to 65 years , body mass index of 30 to 60 kg/m2 , desire to lose weight , elevated lipid levels ( total cholesterol level > 5.17 mmol/L [ > 200 mg/dL ] , low-density lipoprotein [ LDL ] cholesterol level > 3.36 mmol/L [ > 130 mg/dL ] , or triglyceride level > 2.26 mmol/L [ 200 mg/dL ] ) , and no serious medical condition . Exclusion criteria were use of any prescription medication in the previous 2 months ( except for oral contraceptives , estrogen therapy , and stable thyroid medication ) , pregnancy or breastfeeding , use of any weight loss diet or diet pills in the previous 6 months , and baseline ketonuria . All participants provided written informed consent , and the institutional review board of Duke University Health System approved the study . Participants received no monetary incentive . Interventions By using a computer-generated simple r and omization list , participants were allocated to receive the low-carbohydrate diet or low-fat diet . The intervention for both groups included group meetings , diet instruction , and an exercise recommendation . Group meetings took place at an outpatient research clinic twice monthly for 3 months , then monthly for 3 months . These meetings typically lasted 1 hour and consisted of diet instruction , supportive counseling , question naires , and biomedical measurements . During the study , participants selected their own menus and prepared or bought their own meals according to the guidelines presented to them . Participants were encouraged to exercise for 30 minutes at least 3 times weekly , but no formal exercise program or incentives were provided . Low-Carbohydrate Diet Using a popular diet book published by a lay press and additional h and outs , trained research staff instructed participants to restrict intake of carbohydrates to less than 20 g/d ( 4 ) . Participants were permitted unlimited amounts of animal foods ( meat , fowl , fish , and shellfish ) , unlimited eggs , 4 oz of hard cheese , 2 cups of salad vegetables ( such as lettuce , spinach , or celery ) , and 1 cup of low-carbohydrate vegetables ( such as broccoli , cauliflower , or squash ) daily . Participants were encouraged to drink 6 to 8 glasses of water daily . When participants were halfway to their goal body weight ( determined at the week 10 visit with assistance from research personnel ) , they were advised to add approximately 5 g of carbohydrates to their daily intake each week until they reached a level at which body weight was maintained . To simulate the practice of the study sponsor , the low-carbohydrate diet group also received daily nutritional supplements ( multivitamin , essential oils , diet formulation , and chromium picolinate ; for a list of the composition of these supplements , see the Appendix ) ( 6 ) . Low-Fat Diet Using a commonly available booklet and additional h and outs , a registered dietitian instructed participants in a diet consisting of less than 30 % of daily energy intake from fat , less than 10 % of daily energy intake from saturated fat , and less than 300 mg of cholesterol daily ( 11 , 12 ) . The recommended energy intake was 2.1 to 4.2 MJ ( 500 to 1000 kcal ) less than the participant 's calculated energy intake for weight maintenance ( body weight in pounds 10 ) ( 13 ) . Primary Outcome Measure Body weight and body mass index were the primary outcome measures . At each visit , participants were weighed on the same calibrated scale while wearing lightweight clothing and no shoes .  Body mass index was calculated as body weight in kilograms divided by height in meters squared . Secondary Outcome Measures Adherence Adherence to the diet was measured by self-report , food records , and , for the low-carbohydrate diet group , urinary ketone assessment . Diet Composition All participants completed a 24-hour recall of food intake at baseline and take-home food records ( 5 consecutive days , including a weekend ) that were collected at each meeting during the study . Participants were instructed on how to document food intake and were given h and outs with examples of how to complete the records . A sample of participants ( 13 in the low-carbohydrate diet group and 7 in the low-fat diet group ) who completed the study was selected for food record analysis by the research staff on the basis of adequacy of detail in their records . A registered dietitian analyzed the food records by using a nutrition software program ( Nutritionist Five , version 1.6 [ First Data Bank , Inc. , San Bruno , California ] ) . Ketonuria Restriction of dietary intake of carbohydrates to less than 40 g/d typically results in ketonuria that is detectable by dipstick analysis , which can be used to monitor adherence to the low-carbohydrate diet ( 14 , 15 ) . At each return visit , participants provided a fresh urine specimen for analysis . The following semi-quantitative scale was used to categorize ketone content : none , trace ( up to 0.9 mmol/L [ 5 mg/dL ] ) , small ( 0.9 to 6.9 mmol/L [ 5 to 40 mg/dL ] ) , moderate ( 6.9 to 13.8 mmol/L [ 40 to 80 mg/dL ] ) , large80 ( 13.8 to 27.5 mmol/L [ 80 to 160 mg/dL ] ) , and large160 ( > 27.5 mmol/L [ > 160 mg/dL ] ) . Body Composition Body composition was estimated by using bioelectric impedance ( model TBF-300A [ Tanita Corp. , Arlington Heights , Illinois ] ) at approximately the same time of day ( afternoon or evening ) at each return visit . In a subset of 33 participants , the percentage of body fat as measured by bioelectric impedance had excellent correlation with the percentage as measured by dual-energy x-ray absorptiometry ( r = 0.93 [ 95 % CI , 0.87 to 0.97 ] ) . Vital Signs Blood pressure and pulse rate were measured in the nondominant arm by using an automated digital cuff ( model HEM-725C [ Omron Corp. , Vernon Hills , Illinois ] ) after the participant had been sitting for 3 minutes . Two measurements were taken at each visit and averaged for the analysis . Serum Lipids and Lipoproteins Serum specimens for lipid measurement were obtained in the morning after at least 8 hours of fasting at the screening visit and at 8 , 16 , and 24 weeks . Other Metabolic Effects Serum tests for sodium , potassium , chloride , urea nitrogen , creatinine , calcium , phosphorus , total protein , albumin , uric acid , total bilirubin , alanine aminotransferase , aspartate aminotransferase , alkaline phosphatase , thyroid-stimulating hormone , iron , hemoglobin , leukocyte count , and platelet count were obtained at the screening visit and at 8 , 16 , and 24 weeks . The glomerular filtration rate was estimated by using an equation that included age ; sex ; race ; and serum levels of albumin , creatinine , and urea nitrogen ( Modification of Diet in Renal Disease Study equation ) ( 16 ) . Adverse Effects At all return visits , participants completed an open-ended question naire on side effects . At the 20- and 24-week visits , participants completed a checklist of the side effects that were most often mentioned during the study . Statistical Analysis Analyses were performed by using S-PLUS software , version 6.1 ( Insightful Corp. , Seattle , Washington ) , or SAS software , version 8.02 ( SAS Institute , Inc. , Cary , North Carolina ) . For categorical outcomes , groups were compared by using the chi-square test or Fisher exact test , as appropriate . For all primary and secondary continuous outcomes , linear mixed-effects models ( PROC MIXED procedure in SAS software ) that included fixed and r and om effects were used to determine expected mean values at each time point and to test hypotheses of group differences . In most body weight and Objective : To determine the effect of high-protein diets , which have recently been promoted for their health benefits , on urinary calcium losses and bone turnover in older subjects . Design : R and omized controlled cross-over study . Setting : Teaching hospital and university . Subjects : Twenty hyperlipidemic men and postmenopausal women ( age 56±2 y ) completed the study . Interventions : One-month test and control phases during which subjects consumed equi-energy metabolic diets high in calcium ( 1578 and 1593 mg/day , respectively ) . On the test diet 11 % of total dietary energy from starch in the control bread was replaced by protein ( wheat gluten ) , result ing in 27 % of energy from protein on the test diet vs 16 % on the control diet . Main outcome measure : Urinary calcium excretion . Results : Compared with the control diet , at week 4 , the test diet increased mean ( ±s.e.m . ) 24 h urinary output of calcium ( 139±15 vs 227±21 mg , P=0.004 ) . The treatment difference in urinary calcium loss correlated with the serum anion gap as a marker of metabolic acid production ( r=0.57 , P=0.011 ) . Serum calcium levels were marginally lower 2.41±0.02 vs 2.38±0.02 mmol/l ( P=0.075 ) , but there was no significant treatment difference in calcium balance , possibly related to the high background calcium intake on both diets . Conclusions : In the presence of high dietary calcium intakes the vegetable protein gluten does not appear to have a negative effect on calcium balance despite increased urinary calcium loss . Sponsorship : The University-Industry Research Partnership Program of the Natural Sciences and Engineering Research Council of Canada , Loblaw Br and s Limited , Toronto , ON , and Kraft Canada Inc. Don Mills , ON . DJAJ is funded as a Canada Research Chair in Metabolism and Nutrition at the University of Toronto by the Federal Government of Canada , Ottawa Objective : To assess the effects of a diet rich in protein of animal origin in comparison to one with a protein intake of about 15 % of the total daily calories on body composition and arterial function . Design : R and omized prospect i ve study with parallel groups . Body weight ( BW ) , blood pressure ( BP ) , main parameters of carbohydrate and lipid metabolism , body mass composition by bioelectrical impedance analysis , forearm blood flow at rest and in the postischaemic phase by strain gauge plethysmography and flow-mediated dilation of the brachial artery by echography were measured at baseline and after 6 months of the dietary intervention . Subjects : In total , 15 clinical ly healthy male volunteers , regularly performing a mixed training three times weekly for 90 min . Intervention : The participants were r and omly prescribed a diet with high ( 1.9 g/kg BW ) or normal ( 1.3 g/kg BW ) protein content . Statistical analysis : Differences between means were evaluated by the t-tests for paired or unpaired data and by one way analysis of variance . The strength of correlation between variables was investigated by bivariate Pearson correlation . Results : Serum cholesterol significantly decreased with both diets in comparison to baseline values , whereas BW was slightly but significantly reduced only by the high-protein ( HP ) diet . No change was detected in BP and the other metabolic parameters . Body mass composition was not significantly modified by either diet . On the other h and , postischaemic flow-mediated dilation of the brachial artery was enhanced by the sole normal protein ( NP ) diet , whereas no change in the forearm blood flow , both at rest and in the postischaemic phase , was detected . Conclusions : These preliminary results indicate that HP diet was found to be not useful in increasing the muscle mass in comparison to a NP intake . In contrast to this , the latter diet seems to enhance the endothelial function of the arterial vessels with a more pronounced dilatation of the lumen in response to the increase in blood flow BACKGROUND : We have previously reported that a fat-reduced high-protein diet had more favourable effects on body weight loss over 6 months than a medium-protein diet . OBJECTIVE : To extend this observation by a further 6–12 months less stringent intervention and a 24 months follow-up . DESIGN : A r and omised 6 months strictly controlled dietary intervention followed by 6–12 months dietary counselling period , and a subsequent 24 months follow-up , comparing an ad libitum , fat-reduced diet ( 30 % of energy ) either high in protein ( 25 % of energy , HP ) or medium in protein ( 12 % of energy , MP).SUBJECTS : A total of 50 overweight and obese subjects ( age : 19–55 y ; BMI : 26–34 kg/m2 ) . MEASUREMENTS : Change in body weight , body composition and blood parameters . RESULTS : After 6 months , the HP group ( n=23 ) achieved a greater weight loss than the MP group ( n=23 ) ( 9.4 vs 5.9 kg ) ( P<0.01 ) . After 12 months , 8 % had dropped out in the HP vs 28 % in the MP group ( P<0.07 ) . After 12 months , the weight loss was not significantly greater among the subjects in the HP group ( 6.2 and 4.3 kg ) , but they had a 10 % greater reduction in intra-abdominal adipose tissue and more in the HP group ( 17 % ) lost > 10 kg than in the MP ( P<0.09 ) . At 24 months , both groups tended to maintain their 12 months weight loss , but more than 50 % were lost to follow-up . CONCLUSION : A fat-reduced diet high in protein seems to enhance weight loss and provide a better long-term maintenance of reduced intra-abdominal fat stores Influence of diet composition on mood during weight-reducing diets was studied in healthy young women of normal weight . A broad range of macronutrient intake was achieved by means of divergent dietary instructions for the composition of a 1,000 kcal per day diet adhered to for six weeks . Global mood during the last three weeks of the diet was significantly better in the “ vegetarian ” than in the “ mixed ” diet group . During this time a significant correlation was observed between relative carbohydrate intake and global mood ( r=−0.74 ; p<0.01 ) and between the ratio of plasma tryptophan to other large neutral amino acids ( a predictor of tryptophan flow into brain ) and global mood ( r=− 0.52 ; p<0.05 ) . Results suggest that group differences are related to differences in carbohydrate intake . It is hypothesized that impairment of central serotonergic function due to reduced tryptophan availability can prompt mood deterioration in situations of relatively low carbohydrate intake A frequently cited concern of very-low-carbohydrate diets is the potential for increased risk of renal disease associated with a higher protein intake . However , to date , no well-controlled r and omized studies have evaluated the long-term effects of very-low-carbohydrate diets on renal function . To study this issue , renal function was assessed in 68 men and women with abdominal obesity ( age 51.5+/-7.7 years , body mass index [ calculated as kg/m(2 ) ] 33.6+/-4.0 ) without preexisting renal dysfunction who were r and omized to consume either an energy-restricted ( approximately 1,433 to 1,672 kcal/day ) , planned isocaloric very-low-carbohydrate ( 4 % total energy as carbohydrate [ 14 g ] , 35 % protein [ 124 g ] , 61 % fat [ 99 g ] ) , or high-carbohydrate diet ( 46 % total energy as carbohydrate [ 162 g ] , 24 % protein [ 85 g ] , 30 % fat [ 49 g ] ) for 1 year . Body weight , serum creatinine , estimated glomerular filtration rate and urinary albumin excretion were assessed before and after 1 year ( April 2006-July 2007 ) . Repeated measures analysis of variance was conducted . Weight loss was similar in both groups ( very-low-carbohydrate : -14.5+/-9.7 kg , high-carbohydrate : -11.6+/-7.3 kg ; P=0.16 ) . By 1 year , there were no changes in either group in serum creatinine levels ( very-low-carbohydrate : 72.4+/-15.1 to 71.3+/-13.8 mumol/L , high-carbohydrate : 78.0+/-16.0 to 77.2+/-13.2 mumol/L ; P=0.93 time x diet effect ) or estimated glomerular filtration rate ( very-low-carbohydrate : 90.0+/-17.0 to 91.2+/-17.8 mL/min/1.73 m(2 ) , high-carbohydrate : 83.8+/-13.8 to 83.6+/-11.8 mL/min/1.73 m(2 ) ; P=0.53 time x diet effect ) . All but one participant was classified as having normoalbuminuria at baseline , and for these participants , urinary albumin excretion values remained in the normoalbuminuria range at 1 year . One participant in high-carbohydrate had microalbuminuria ( 41.8 microg/min ) at baseline , which decreased to a value of 3.1 microg/min ( classified as normoalbuminuria ) at 1 year . This study provides preliminary evidence that long-term weight loss with a very-low-carbohydrate diet does not adversely affect renal function compared with a high-carbohydrate diet in obese individuals with normal renal function CONTEXT Consolidation and maintenance of peak bone mass in young adulthood may be compromised by inactivity , low dietary calcium , and diet-induced weight loss . OBJECTIVE We aim ed to determine whether higher intakes of dairy foods , dietary calcium , and protein during diet- and exercise-induced weight loss affected markers of bone health . PARTICIPANTS Participants included premenopausal overweight and obese women . DESIGN /INTERVENTION Ninety participants were r and omized into three groups ( n = 30 per group ) : high protein and high dairy ( HPHD ) , adequate protein and medium dairy ( APMD ) , and adequate protein and low dairy ( APLD ) , differing in dietary protein ( 30 , 15 , or 15 % of energy , respectively ) , dairy foods ( 15 , 7.5 , or < 2 % of energy from protein , respectively ) , and dietary calcium ( ∼1600 , ∼1000 , or < 500 mg/d , respectively ) . OUTCOME MEASURES Serum and urine bone turnover biomarkers , serum osteoprotegerin ( OPG ) , receptor activator of nuclear factor-κB lig and ( RANKL ) , PTH , 25-hydroxyvitamin D , leptin , and adiponectin measured at 0 and 16 wk . RESULTS All groups lost equivalent body weight ( P < 0.05 ) . N-telopeptide , C-telopeptide ( CTX ) , urinary deoxypyridinoline , and osteocalcin increased in APLD ( P < 0.01 ) , whereas in HPHD , osteocalcin and procollagen 1 amino-terminal propeptide ( P1NP ) increased ( P < 0.05 ) , and all resorption markers remained unchanged . P1NP to CTX and OPG to RANKL ratios increased in HPHD ( P < 0.005 ) , and P1NP to CTX ratio decreased in APLD ( P < 0.05 ) . PTH decreased in HPHD and APMD vs. APLD ( P < 0.005 ) , and 25-hydroxyvitamin D increased in HPHD ( P < 0.05 ) , remained unchanged in APMD , and decreased in APLD ( P < 0.05 ) . Leptin decreased and adiponectin increased in APMD and HPHD only ( P < 0.001 ) . CONCLUSIONS Hypoenergetic diets higher in dairy foods , dietary calcium , and protein with daily exercise , favorably affected important bone health biomarkers vs. diets with less of these bone-supporting nutrients OBJECTIVE The long-term effect of dietary protein on bone mineralization is not well understood . RESEARCH METHODS AND PROCEDURES Sixty-five overweight ( body mass index , 25 to 29.9 kg/m(2 ) ) or obese ( > or = 30 kg/m(2 ) ) subjects were enrolled in a r and omized , placebo-controlled , 6-month dietary-intervention study comparing two controlled ad libitum diets with matched fat contents : high protein ( HP ) or low protein ( LP ) . Body composition was assessed by DXA . RESULTS In the HP group , dietary-protein intake increased from 91.4 g/d to a 6-month intervention mean of 107.8 g/d ( p < 0.05 ) and decreased in the LP group from 91.1 g/d to 70.4 g/d ( p < 0.05 ) . Total weight loss after 6 months was 8.9 kg in the HP group , 5.1 kg in the LP group , and none in the control group . After 6 months , bone mineral content ( BMC ) had declined by 111 + /- 13 g ( 4 % ) in the HP group and by 85 + /- 13 g ( 3 % ) in the LP group ( not significant ) . Loss of BMC was more positively correlated with loss of body fat mass ( r = 0.83 ; p < 0.0001 ) than with loss of body weight . Six-month BMC loss , adjusted for differences in fat loss , was greater in the LP group than in the HP group [ difference in LP vs. HP , 44.8 g ( 95 % confidence interval , 16 to 73.8 g ) ; p < 0.05 ] . Independent of change in body weight and composition during the intervention , highprotein intake was associated with a diminished loss of BMC ( p < 0.01 ) . DISCUSSION Body-fat loss was the major determinant of loss of BMC , and we found no adverse effects of 6 months of high-protein intake on BMC OBJECTIVE The ability to accurately identify articles about therapy in large bibliographic data bases such as EMBASE is important for research ers and clinicians . Our study aim ed to develop optimal search strategies for detecting sound treatment studies in EMBASE in the year 2000 . METHODS H and search es of journals were compared with retrievals from EMBASE for c and i date search strategies . Six trained research assistants review ed fifty-five journals indexed in EMBASE and rated articles using purpose and quality indicators . C and i date search strategies were developed for identifying treatment articles and then tested , and the retrievals were compared with the h and - search data . The operating characteristics of the strategies were calculated . RESULTS Three thous and eight hundred fifty articles were original studies on treatment , of which 1,256 ( 32.6 % ) were method ologically sound . Combining search terms revealed a top performing strategy ( r and om:.tw . OR clinical trial:.mp . OR exp health care quality ) with sensitivity of 98.9 % and specificity of 72.0 % . Maximizing specificity , a top performing strategy ( double-blind:.mp . OR placebo:.tw . OR blind : .tw . ) achieved a value over 96.0 % , but with compromised sensitivity at 51.7 % . A 3-term strategy achieved the best optimization of sensitivity and specificity ( r and om:.tw . OR placebo:.mp . OR double-blind:.tw . ) , with both these values over 92.0 % . CONCLUSION Search strategies can achieve high performance for retrieving sound treatment studies in EMBASE BACKGROUND Very low-carbohydrate ( LC ) diets are often used to promote weight loss , but the long-term effects on psychological function remain unknown . METHODS A total of 106 overweight and obese participants ( mean [ SE ] age , 50.0 [ 0.8 ] years ; mean [ SE ] body mass index [ calculated as weight in kilograms divided by height in meters squared ] , 33.7 [ 0.4 ] ) were r and omly assigned either to an energy-restricted ( approximately 1433 - 1672 kcal [ to convert to kilojoules , multiply by 4.186 ] ) , planned isocaloric , very low-carbohydrate , high-fat ( LC ) diet or to a high-carbohydrate , low-fat ( LF ) diet for 1 year . Changes in body weight , psychological mood and well-being ( Profile of Mood States , Beck Depression Inventory , and Spielberger State Anxiety Inventory scores ) , and cognitive functioning ( working memory and speed of processing ) were assessed . RESULTS By 1 year , the overall mean ( SE ) weight loss was 13.7 ( 1.8 ) kg , with no significant difference between groups ( P = .26 ) . Over the course of the study , there were significant time x diet interactions for Spielberger State Anxiety Inventory , Beck Depression Inventory , and Profile of Mood States scores for total mood disturbance , anger-hostility , confusion-bewilderment , and depression-dejection ( P < .05 ) as a result of greater improvements in these psychological mood states for the LF diet compared with the LC diet . Working memory improved by 1 year ( P < .001 for time ) , but speed of processing remained largely unchanged , with no effect of diet composition on either cognitive domain . CONCLUSIONS Over 1 year , there was a favorable effect of an energy-restricted LF diet compared with an isocaloric LC diet on mood state and affect in overweight and obese individuals . Both diets had similar effects on working memory and speed of processing . Trial Registration anzctr.org.au Identifier : 12606000203550
target: Adverse gastrointestinal events were more common with high-protein diets .
  Multivariable meta-regression analysis showed no significant dose response with higher protein intake .
  Conclusions : Higher-protein diets  probably improve adiposity , blood pressure and triglyceride levels , but these effects are small and need to be weighed against the potential for harms
background: Background / Objectives : Numerous r and omised controlled trials ( RCTs ) published in first tier medical journals have evaluated the health effects of diets high in protein .
  We conducted a rigorous systematic review of RCTs comparing higher- and lower-protein diets .