title: Zinc and copper nutriture in obese men receiving very low calorie diets of soy or collagen protein.
abstract: Balance studies for Zn and Cu were conducted over 40 days in 10 obese men housed in a metabolic balance unit. Two weight reduction diets providing 400 kcal and 100 g protein daily were administered; to five subjects, a collagen diet which was severely deficient in both Zn and Cu, and to another five subjects, a soy diet which provided a marginal intake of Zn and an adequate intake of Cu. Zn and Cu content of diets, plasma, red blood cells, urine, and feces were determined during eight 5-day periods. Balances were corrected for lean tissue catabolism or deposition. Holter ECG monitoring and measurement of the QTc interval were done on days 0 and 40. Both diets resulted in elevated plasma and red blood cell concentrations of Zn and Cu and in high urinary and fecal losses of Zn. By day 40, 6 of 10 subjects were in negative Zn balance. Urinary Zn was inversely correlated with measures of lean tissue catabolism. During each period, Cu balance was markedly positive in the soy-diet group and negative in the collagen-diet group. Shortening of prolonged QTc intervals was related to the Cu but not Zn status of the individual.
mesh_terms: D000328:Adult; D001835:Body Weight; D003094:Collagen / Q000627:therapeutic use; D003300:Copper / Q000172:deficiency* / Q000378:metabolism; D004038:Diet, Reducing / Q000009:adverse effects*; D004044:Dietary Proteins / Q000627:therapeutic use*; D004562:Electrocardiography; D005243:Feces / Q000032:analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000178:diet therapy* / Q000378:metabolism; D014674:Plant Proteins, Dietary / Q000627:therapeutic use; D030262:Soybean Proteins; D013025:Glycine max; D013997:Time Factors; D015032:Zinc / Q000172:deficiency* / Q000378:metabolism
chemical_list: D004044:Dietary Proteins; D014674:Plant Proteins, Dietary; D030262:Soybean Proteins; D003300:Copper; D003094:Collagen; D015032:Zinc