Consequences of modified fasting in obese pediatric and adolescent patients: effect of a carbohydrate-free diet on serum proteins.

Serum proteins were monitored during three studies of obese adolescents treated with protein-supplemented fasting in a clinical research center. In the first study of nine patients, small but significant decreases were noted for total serum protein, albumin, transferrin, retinol-binding protein, and complement beta 1c after 4 wk of carbohydrate-free protein-supplemented fast. In a further study of four of these same patients, the substitution of 400 glucose cal for 400 fat cal in a 5th wk of dietary study returned the total protein and retinol-binding protein concentrations to base-line levels. In a 3rd study of four patients, only complement beta 1c was significantly below base-line concentrations after 3 wk on a carbohydrate-containing protein-supplemented fast. There is an apparent metabolic effect of carbohydrate ingestion on maintaining usual concentrations of serum proteins.