RT Journal Article
SR Electronic
T1 Comparative Effects of Low-Carbohydrate High-Protein Versus Low-Fat Diets on the Kidney
JF Clinical Journal of the American Society of Nephrology
JO CLIN J AM SOC NEPHROL
FD American Society of Nephrology
SP 1103
OP 1111
DO 10.2215/CJN.11741111
VO 7
IS 7
A1 Friedman, Allon N.
A1 Ogden, Lorraine G.
A1 Foster, Gary D.
A1 Klein, Samuel
A1 Stein, Richard
A1 Miller, Bernard
A1 Hill, James O.
A1 Brill, Carrie
A1 Bailer, Brooke
A1 Rosenbaum, Diane R.
A1 Wyatt, Holly R.
YR 2012
UL http://cjasn.asnjournals.org/content/7/7/1103.abstract
AB Background and objectives Concerns exist about deleterious renal effects of low-carbohydrate high-protein weight loss diets. This issue was addressed in a secondary analysis of a parallel randomized, controlled long-term trial.Design, setting, participants, and measurements Between 2003 and 2007, 307 obese adults without serious medical illnesses at three United States academic centers were randomly assigned to a low-carbohydrate high-protein or a low-fat weight-loss diet for 24 months. Main outcomes included renal filtration (GFR) indices (serum creatinine, cystatin C, creatinine clearance); 24-hour urinary volume; albumin; calcium excretion; and serum solutes at 3, 12, and 24 months.Results Compared with the low-fat diet, low-carbohydrate high-protein consumption was associated with minor reductions in serum creatinine (relative difference, −4.2%) and cystatin C (−8.4%) at 3 months and relative increases in creatinine clearance at 3 (15.8 ml/min) and 12 (20.8 ml/min) months; serum urea at 3 (14.4%), 12 (9.0%), and 24 (8.2%) months; and 24-hour urinary volume at 12 (438 ml) and 24 (268 ml) months. Urinary calcium excretion increased at 3 (36.1%) and 12 (35.7%) months without changes in bone density or clinical presentations of new kidney stones.Conclusions In healthy obese individuals, a low-carbohydrate high-protein weight-loss diet over 2 years was not associated with noticeably harmful effects on GFR, albuminuria, or fluid and electrolyte balance compared with a low-fat diet. Further follow-up is needed to determine even longer-term effects on kidney function.