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 / 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 .
Renal function following long-term weight loss in individuals with abdominal obesity on a very-low-carbohydrate diet vs high-carbohydrate diet.
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
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 / 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 .