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Biomedical subjects

J L Kelsay

Publications and source records attributed to J L Kelsay.

35 records · Page 2Linked to original sources

Mineral balances of human subjects consuming spinach in a low-fiber diet and in a diet containing fruits and vegetables.

The effects of spinach in the diet on mineral balances were examined in 12 men who consumed three controlled diets for 4 wk each. Diet 1, a low-fiber diet, contained spinach, which is high in oxalic acid, every other day. Diet 2 contained fiber in fruits and vegetables, including spinach every other day. Diet 3 was the same as diet 2 except that cauliflower, which is low in oxalic acid, replaced the spinach. During wk 4, mean balances of calcium, magnesium, and zinc on diet 2 were negative and significantly lower than those on diet 1. Magnesium and zinc balances during wk 4 were also significantly lower on diet 2 than on diet 3. Mean balances of these minerals were not significantly lower on diet 2 during wk 3, nor were there any significant differences among mineral balances when wk 3 and 4 were considered together. Fecal oxalic acid was significantly greater on diet 2 than on diet 1 during both wk 3 and 4.

Adult↗

Effect of fiber from fruits and vegetables on metabolic responses of human subjects: fiber intakes, fecal excretions, and apparent digestibilities.

Intakes and excretions of fiber were determined for 12 men consuming controlled diets containing fruits and vegetables (high fiber diet) or fruit and vegetable juices (low fiber diet) for periods of 26 days. The fiber in the low fiber diet appeared to be mostly hemicellulose, with an apparent digestibility of 95%. Apparent digestibilities of hemicellulose, cellulose, and lignin in the high fiber diet were 88, 42, and 18%, respectively. Small amounts of uronic acids were detected in the feces, but there is no certainty that they were derived from pectin. Linear regressions indicate that fiber intakes, rather than fiber disappearance, influenced the fecal volume.

Adult↗

The effect of kind of carbohydrate in the diet and use of oral contraceptives on metabolism of young women. II. Serum lipid levels.

The response of lipids in the blood between two groups of six young women was compared. Group 1 took oral contraceptives and group 2 had never taken oral contraceptives. Two experimental diets supplied about 13% of the calories from protein, 36% from fat, and 51% from carbohydrate. Of the carbohydrate, 84% was either sucrose or wheat starch. Each diet was fed for 4 weeks in a cross-over design. In the portion of the research presented here, subjects were fed a high sucrose meal before each dietary period and after weeks 1 and 3 of each dietary period. Blood lipids were measured before and 30, 60, 120, and 180 min after each meal. Cholesterol and lipoproteins were not affected by the sucrose meal, but free fatty acid levels decreased significantly in both groups. The serum levels of triglycerides, beta-lipoproteins, and cholesterol were significantly higher in users than in nonusers of oral contraceptives. Free fatty acid levels were affected by an interaction between diet and time, and the decrease in response was greater after the sucrose than after the wheat starch diet. Triglycerides, cholesterol, and total lipids were not significantly different after the two carbohydrate diets.

Adult↗

The effect of kind of carbohydrate in the diet and use of oral contraceptives on metabolism of young women. III. Serum glucose, insulin, and glucagon.

Responses of glucose, insulin, and glucagon in serum to a sucrose load dose of young women taking oral contraceptives (OC) were compared to responses to the load dose of women who had never taken OC. Two experimental diets contained about 13% of the calories from protein, 36% from fat, and 51% from carbohydrate. Of the carbohydrate 84% was either sucrose of wheat starch. The diets were fed in a crossover design. Subjects were fed a sucrose load (1 g/kg) before and after weeks 1 and 3 of each dietary period. Parameters were measured in blood drawn before and 30, 60, 120, and 180 min after the meal. Levels of serum glucagon and responses of serum glucose and insulin to sucrose load were significantly higher in OC users than in controls. Glucose and insulin rose significantly after the sucrose load. Time significantly affected glucose and insulin. The OC-time interaction also was significant for glucose and insulin levels. The OC users generally had higher peak levels of glucose and insulin and took longer to return to fasting levels than did the controls. After 3 weeks on the diet, the glucose and insulin responses of the OC users, but not of the controls, were significantly greater on the sucrose than on the starch diet. The response of the insulin/glucagon ratio to the sucrose load was not significantly affected by the OC use.

Blood Glucose↗

Effect of fiber from fruits and vegetables on metabolic responses of human subjects. III. Zinc, copper, and phosphorus balances.

Intakes and excretions of zinc, copper, and phosphorus were determined for 12 men when they consumed a diet low in fiber and when they consumed a diet containing fiber from fruits and vegetables (high-fiber diet). All subjects consumed both diets for 26 days each. The low-fiber diet was supplemented with copper so that it was equivalent to the high-fiber diet in this respect. Mean daily intakes on the low- and high-fiber diets, respectively, were: zinc, 13.2 and 12.6 mg; copper, 1.8 and 1.6 mg; phosphorus, 1.639 and 1.690 g. Mean daily balances on the low- and high-fiber diets, respectively, were: zinc, +3.5 and -0.9 mg; copper, +0.2 and -0.4 mg; phosphorus, +0.361 and +0.292 g. Zinc and copper balances differed significantly on the two diets (P less than 0.001 and P less than 0.005, respectively, but phosphorus balances did not. The fiber supplied by the fruits and vegetables contained more lignin and cellulose and less hemicellulose than would an equivalent amount of fiber from bran. The bran would supply more magnesium, zinc, and copper than this particular diet containing fruits and vegetables.

Adult↗

Effect of fiber from fruits and vegetables on metabolic responses of human subjects, II. Calcium, magnesium, iron, and silicon balances.

Intakes and excretions of calcium, magnesium, iron, and silicon were determined for 12 men consuming controlled diets containing fruits and vegetables (high fiber diet) or fruit and vegetable juices (low fiber diet) for periods of 26 days. Magnesium and iron were added to the low fiber diet to make the two diets as equivalent as possible in these respects. Mean daily intakes on the low and high fiber diets, respectively, were: calcium, 1070 and 1166 mg; magnesium, 355 and 322 mg; iron, 21.8 and 26.4 mg; silicon, 21.6 and 45.8 mg. Mean daily balances on the low and high fiber diets repectively, were: calcium +72 and -122 mg; magnesium, +28 and -32 mg; iron, +3.8 and +4.6 mg; silicon, -3.5 and -14.6 mg. Calcium magnesium, and silicon balances were significantly lower on the high than on the low fiber diet (P less than 0.01).

Adult↗

Effect of fiber from fruits and vegetables on metabolic responses of human subjects I. Bowel transit time, number of defecations, fecal weight, urinary excretions of energy and nitrogen and apparent digestibilities of energy, nitrogen, and fat.

Twelve men 37 to 58 years of age consumed two diets for a period of 26 days each in a cross-over design. The high fiber diet contained fruits and vegetables and the lower fiber diet contained fruit and vegetable juices. Neither diet contained whole grain cereals or nuts. Some nutrients were added to the low fiber diet in order to make the diets equivalent insofar as possible in all respects except fiber. The inclusion of fruits and vegetables in the diet decreased bowel transit time, increased fecal weight, increased number of defecations, increased fecal excretions and decreased apparent digestibilities of energy, nitrogen, and fat. Six of the 12 subjects had diastolic blood pressure of 80 or more when consuming the low fiber diet. The diastolic blood pressures of these six men were significantly lower when the high fiber diet was consumed.

Adult↗

The effect of kind of carbohydrate in the diet and use of oral contraceptives on metabolism of young women. I. Blood and urinary lactate, uric acid, and phosphorus.

Six oral contraceptive (OC) users and six control subjects consumed diets in which 43% of the calories came from either sucrose or starch for 4 weeks in a cross-over design. Kind of carbohydrate in the diet had no effect on blood lactate response to a sucrose load, but lactate response of OC users was greater than that of control subjects. Kind of carbohydrate in the diet did not affect urinary lactate excretion after a sucrose load; however, OC users excreted more lactate than did controls and there was a significant interaction between dietary carbohydrate and OC use. Serum uric acid levels were significantly higher when the sucrose diet was consumed, but levels were not affected by OC use. Serum phosphorus levels were not affected by kind of carbohydrate in the diet but were higher in control subjects than in OC users and there was a significant interaction between diet and OC use. There were no significant differences in urinary uric acid and phosphorus excretions after sucrose loads or in 24-hr urinary excretions of uric acid, phosphorus, or urea due to kind of carbohydrate in the diet or OC use.

Adult↗