Obesity and weight loss alter serum polyunsaturated lipids in humans

Serum omega 6 (n-6) fatty acids were assessed in 12 obese women during an outpatient very-low-calorie diet (VLCD). Ten subjects (S10) achieved a mean weight loss of 17 kg over 3-5 mo (initial weight-for-height 157%). Serum was obtained before (baseline) and monthly during the VLCD and from five of them (S5) after 2-3 mo of weight stability (refed) at 21 kg of loss. At baseline for S10, the serum phospholipid (PL) 20:4 omega 6 was 9.16 wt% and differed from normal (12.81 wt%) by P less than 0.0001, but cholesterol ester (CE) 20:4 omega 6 did not differ from normal. During 3 mo of VLCD, the S10 serum PL and CE 18:2 omega 6 fell (P less than 0.005 and 0.0001, respectively). Serum PL 20:4 omega 6 rose to normal during VLCD months 1-3 (P less than 0.01) while the serum CE 20:4 omega 6 rose above normal (P less than 0.0002). During the VLCD, S5 results paralleled S10. However when refed, S5 PL and CE 18:2 omega 6 and 20:4 omega 6 all reverted to baseline (PL 20:4 omega 6 below normal, P less than 0.001). Serum PL 20:4 omega 6 is low in moderate obesity, corrects to normal during a VLCD, but regresses to the predict abnormality after weight loss.     

Effects of a very-low-calorie diet on metabolic control and cardiovascular risk factors in the treatment of obese non-insulin-dependent diabetics

Ten obese non-insulin-dependent diabetics (six men, four women) with secondary drug failure were treated with a hypocaloric diet only (2100-3350 kJ/d) for 3 mo to assess the effects of weight reduction on metabolic control, energy production rate, and cardiovascular risk factors. During the 3 mo of follow-up the mean body weight decreased from 101.0 +/- 7.2 (means +/- SEM) to 87.2 +/- 5.5 kg (p less than 0.001). Basal energy production rate (kJ/min) decreased by 8.5%. Fasting blood glucose declined from 12.3 +/- 0.4 to 10.5 +/- 0.7 mmol/L (p less than 0.05) but mean diurnal glucose and glycosylated hemoglobin A1c did not change significantly. Serum total cholesterol was decreased at 2 wk but at 3 mo it did not differ significantly from the baseline value. A marked reduction was observed in serum triglycerides after 3 mo (4.57 +/- 1.0 vs 2.18 +/- 0.26 mmol/L, p = 0.012). The high-density lipoprotein (HDL) cholesterol increased after weight reduction (0.96 +/- 0.06 vs 1.11 +/- 0.05 mmol/L, p = 0.009). A significant decline was found in both systolic (152 +/- 6 vs 133 +/- 3 mm Hg, p = 0.004) and diastolic blood pressure (92 +/- 3 vs 81 +/- 3 mm Hg, p = 0.007). There was no evidence of linoleic acid deficiency after this diet.     

Fasting increases serum total cholesterol, LDL cholesterol and apolipoprotein B in healthy, nonobese humans.

Voluntary fasting is practiced by many humans in an attempt to lose body weight. Conflicting results have been published on the effects of food deprivation on serum lipids. To study the effect of acute starvation on serum lipids, 10 nonobese (93-124% of ideal body weight), healthy adults (6 men, 4 women, 21-38 y old) fasted (no energy) for 7 d. Fasting increased total serum cholesterol from 4.90 +/- 0.23 to 6.73 +/- 0.41 mmol/L (37.3 +/- 5.0%; P < 0.0001) and LDL cholesterol from 2.95 +/- 0.21 to 4.90 +/- 0.36 mmol/L (66.1 +/- 6. 6%; P < 0.0001). Serum apolipoprotein B (apo B) increased from 0.84 +/- 0.06 to 1.37 +/- 0.11 g/L (65.0 +/- 9.2%; P < 0.0001). The increases in serum cholesterol, LDL and apo B were associated with weight loss. Fasting did not affect serum concentrations of triacylglycerol and HDL cholesterol. Serum concentrations of insulin-like growth factor-I (IGF-I) decreased from 246 +/- 29 (prefast) to 87 +/- 10 microg/L after 1 wk of fasting (P < 0.0001). We conclude that, in nonobese subjects, fasting is accompanied by increases in serum cholesterol, LDL and apo B concentrations, whereas IGF-I levels are decreased.     

Reducing parenteral energy and protein intake improves metabolic homeostasis after bone marrow transplantation

The purpose of this prospective study was to compare the metabolic effects of reducing parenteral energy and protein intake in bone-marrow-transplant (BMT) patients from 150% (hi-TPN group) to 100% (lo-TPN group) basal energy expenditure. Cytotoxic therapy was given on days 1-5, BMT on day 6, and TPN beginning on days 6 or 7. The lo-TPN group exhibited higher serum albumin (38 +/- 0.4 vs 32 +/- 0.4 g/L, P less than 0.01) but similar nitrogen balance (-83 +/- 8 vs -86 +/- 8 mg.kg-1.d-1, P greater than 0.05). Serum Na+ remained greater than 134 +/- 1 mmol/L in the lo-TPN group but fell to 127 +/- 1 mmol/L in the hi-TPN group (P less than 0.001) despite similar Na+ intakes and balances. Serum K+ remained less than 4.4 +/- 0.2 mmol/L in the lo-TPN group but rose to 5.1 +/- 0.1 mmol/L in the hi-TPN group (P less than 0.01) despite similar K+ intakes and balances. Delivering TPN at lower-than-normal rates after BMT appears to minimize Na+ and K+ disturbances and improve serum albumin concentrations without having any adverse effect on nitrogen balance.     

Effects of a low carbohydrate isoenergetic diet on sleep behavior and pulmonary functions in healthy female adult humans

To study the effects of a low carbohydrate, isoenergetic diet on pulmonary physiology and sleep behavior, we measured pulmonary functions and respiratory gas exchange and carried out ambulatory electroencephalographic studies after a week's intake of isoenergetic diet containing only 50 g carbohydrate per day in 6 healthy female adult humans in a free-living condition. Compared with their normal intake, during the week of low carbohydrate intake there was a rise in the level of fasting plasma 3-hydroxybutyrate from 0.12 +/- 0.07 (mean +/- SD) to 1.01 +/- 0.40 mmol/L(P less than 0.01, paired t-test); a fall in serum bicarbonate from 26.2 +/- 0.75 to 25.0 +/- 1.41 mmol/L (P less than 0.05) and in serum chloride from 107 +/- 1.3 to 105 +/- 1.8 mmol/L (P less than 0.05). Serum urea rose from 4.3 +/- 0.71 to 5.7 +/- 0.70 mmol/L (P less than 0.01), and serum uric acid from 0.34 +/- 0.08 to 0.39 +/- 0.10 mmol/L (P less than 0.05). Functional residual capacity was increased from 2.07 +/- 0.35 to 2.26 +/- 0.34 L (P less than 0.01). Respiratory gas exchange ratio fell from 0.81 +/- 0.05 to 0.75 +/- 0.04 (P less than 0.05) and partial pressure of expired carbon dioxide reduced from 22 +/- 3.3 to 21 +/- 3.1 mmHg (P less than 0.05). There was a reduction in endogenous carbon dioxide production and arterial carbon dioxide tension. An analysis of ambulatory electroencephalogram showed that REM latency increased from 66 +/- 8 to 111 +/- 38 min (P less than 0.05), with no significant changes in sleep time and stages. These studies show that a low carbohydrate isoenergetic diet is tolerable, influences sleep behavior, reduces carbon dioxide production and respiratory gas exchange ratio, and may be therapeutically useful in patients with hypercapnic respiratory failure.     

Changes in plasma lipoproteins during low-fat, high-carbohydrate diets: effects of energy intake

BACKGROUND: Low-fat diets can increase plasma triacylglycerol and reduce HDL cholesterol. Changes in energy intake and body weight can influence the lipoprotein response. OBJECTIVE: We sought to prospectively examine the effects of euenergetic and ad libitum dietary fat restriction on plasma lipoproteins in healthy postmenopausal women. DESIGN: Participants first received a controlled euenergetic diet in which dietary fat was reduced stepwise from 35% to 25% to 15% over 4 mo. Thereafter, participants followed an ad libitum 15%-fat diet for 8 mo; 54 women completed the intervention. RESULTS: During the controlled euenergetic diet, plasma triacylglycerol increased from 1.70 +/- 0.10 to 2.30 +/- 0.16 mmol/L, total cholesterol decreased from 5.87 +/- 0.13 to 5.53 +/- 0. 13 mmol/L, LDL cholesterol decreased from 3.41 +/- 0.10 to 2.87 +/- 0.10 mmol/L, HDL cholesterol decreased from 1.76 +/- 0.08 to 1.50 +/- 0.08 mmol/L, and apolipoprotein (apo) A-I decreased from 5.11 +/- 0.14 to 4.78 +/- 0.14 mmol/L (P < 0.0001 for all changes). Hormone replacement therapy did not affect the relative change in HDL cholesterol. Plasma glucose, insulin, hemoglobin A(1C,) free fatty acid, and apo B concentrations did not change significantly. During the ad libitum 15%-fat diet, participants lost 4.6 +/- 0.4 kg. Plasma triacylglycerol and LDL cholesterol returned to baseline values (1.77 +/- 0.12 and 3.31 +/- 0.08 mmol/L, respectively), whereas HDL cholesterol and apo A-I remained low (1.40 +/- 0.08 and 4.82 +/- 0.18 mmol/L, respectively). HDL cholesterol and apo A-I concentrations stabilized in subjects who were not receiving hormone replacement therapy but continued to decline in women who were receiving hormone therapy. CONCLUSIONS: The ad libitum 15%-fat diet resulted in significant weight loss. The euenergetic but not the ad libitum diet caused hypertriacylglycerolemia. HDL cholesterol decreased during both low-fat diets.     

Reduction of serum estradiol in postmenopausal women given free access to low-fat high-carbohydrate diet.

The short-term effects of a low-fat (less than 10% of cal) high-fiber (35-45 g.1000 kcal-1.day-1) diet on estradiol levels were studied in 13 postmenopausal women under residential conditions with cafeteria food service. During this diet study (mean +/- SE duration 22 +/- 4.6 days), body weight declined from 84.9 +/- 6.4 to 82.3 +/- 6.0 kg (P less than 0.001). Serum cholesterol and low-density and high-density lipoprotein cholesterol also fell significantly, whereas triglycerides remained constant. Serum estradiol fell from 18.1 +/- 3.6 to 9.4 +/- 2.4 pg/ml (P less than 0.05). This study demonstrates that serum estradiol levels are reduced in normal to over-weight postmenopausal women given free access to a low-fat high-fiber diet. Most of these women were in negative caloric balance during the study, suggesting that short-term changes in caloric balance may affect estrogen synthesis in postmenopausal women prior to a large decrease in fat mass.     

Predictors of weight loss and reversal of comorbidities in malabsorptive bariatric surgery

BACKGROUND: Cardiovascular and metabolic comorbidities are dramatically increased in severe obesity, a condition highly resistant to nonsurgical therapy. OBJECTIVE: The objective was to identify predictors of weight loss and reversal of comorbidity in obese patients undergoing malabsorptive bariatric surgery. DESIGN: Morbidly obese men and women (n = 107) were studied before and 2 y after biliopancreatic diversion (BPD). Body composition, serum lipid profile, oral glucose tolerance, and blood pressure were measured. Insulin sensitivity was determined by use of a euglycemic clamp. The length of the small intestine was measured during surgery. RESULTS: Intestinal length was 671 +/- 99 cm, and the residual absorbing intestine after BPD ranged from 54% to 24% of initial length. Patients lost an average of 36% of their initial weight, with approximately 50% of them reaching a body mass index (in kg/m(2)) < 30. Serum cholesterol decreased (from 4.58 +/- 1.11 to 3.34 +/- 0.73 mmol/L; P < 0.0001), as did serum triacylglycerols (from 1.52 +/- 0.59 to 0.88 +/- 0.35 mmol/L; P < 0.0001), whereas insulin sensitivity rose 150% (from 26 +/- 4 to 64 +/- 11 micromol . min(-1) . kg fat-free mass(-1); P < 0.0001). Diabetes (in 23% of patients before surgery) and hypertension (in 83%) were reduced (by 88% and 96%, respectively) after surgery. In a multivariate model (including sex, age, intestinal length, presence of diabetes, insulin sensitivity, and initial fat mass), age and diabetes were independent, negative predictors of weight loss, whereas initial fat mass was a strong positive predictor (r(2) = 0.51). CONCLUSIONS: Two years after BPD in morbidly obese patients, comorbidities are largely corrected and insulin resistance is fully reversed despite persistent obesity. Initial fat mass, but not residual intestinal length, is the strongest predictor of weight loss after BPD.     

Potassium, magnesium, and calcium balance in obese adolescents on a protein-sparing modified fast

Ten obese adolescents consumed the protein-sparing modified fast (PSMF), a high-protein, low-carbohydrate diet, for 92 +/- 19 d and lost 14.7 +/- 5.3 kg. The effect of weight loss using the PSMF on potassium, magnesium, and calcium was evaluated using balance method at days 2-4 and 12-20, RBC-Mg, RBC-K and total body K (TBK). The vitamin- and mineral-supplemented PSMF allowed positive Ca and K balance and improved Mg balance (p less than 0.005). TBK decreased significantly, 118.7 +/- 13.7 to 97.4 +/- 1.0 g (3.04 +/- 0.35 to 2.50 +/- 0.03 mol) from baseline to 90 d (p less than 0.001), with no change in the RBC-K concentration. An unexpected finding was a significant decrease in RBC-Mg, 3.2 +/- 1.1 to 1.8 +/- 0.3 mmol/L (p less than 0.001) after 60-90 d on the diet despite maintenance of normal serum Mg level.     

Two-year changes in lipids and lipoproteins associated with the maintenance of a 5% to 10% reduction in initial weight: some findings and some questions

OBJECTIVE: This study assessed whether a 5% to 10% reduction in initial weight would be associated with as favorable long-term (i.e., 100 weeks) changes in lipids and lipoproteins, as have been observed on a short-term basis (i.e., 8 weeks). RESEARCH METHODS AND PROCEDURES: This was a prospective evaluation of 25 obese women, each of whom had lost > or =5% of initial weight during 48 weeks of treatment and had maintained a weight loss of this magnitude at 1-year follow-up (week 100). Lipids and lipoproteins were obtained at baseline and at weeks 8, 24, 48, and 100. All participants had a baseline total cholesterol > or =5.17 mmol/L (200 mg/dL). RESULTS: At the end of the first 8 weeks, weight fell an average of 11.7+/-2.8%, total cholesterol 20.6+/-7.5%, low-density-lipoprotein (LDL) cholesterol 23.0+/-18.1%, and triglycerides 26.0+/-20.1%. At week 48, weight had fallen to 20.1+/-7.0% below baseline, but total cholesterol and LDL cholesterol were reduced only 11.5+/-10.4% and 12.0+/-14.0% below baseline, respectively. These latter reductions were significantly (p<0.05) smaller than those observed at week 8, despite the larger weight loss at week 48. High-density-lipoprotein cholesterol declined significantly (p<0.05) during the first 8 weeks, but returned to baseline values by week 24. Patients gained 7.4+/-7.4 kg from weeks 48 to 100, during which time total and LDL cholesterol (but not triglycerides) rose significantly (p<0.05). Patients who, at week 100, maintained losses >10% of initial weight had significantly greater reductions in total and LDL cholesterol values than did patients who maintained losses of only 5% to 10% of initial weight. DISCUSSION: Results of this study underscore the importance of assessing long-term changes in weight-related health complications when patients have lost weight but are no longer dieting (and exercising) as aggressively as they did during the initial months of treatment.     

Malnutrition in tubefed nursing home patients with pressure sores.

This study compares the nutritional status and dietary intake of 14 tubefed nursing home patients with pressure sores (age: 70 +/- 5 years, mean +/- SEM) to 12 tubefed patient-controls without sores (age: 60 +/- 7 years). Patients tended to have higher calorie intake (32 +/- 3 kcal/kg) than patient-controls (26 +/- 2 kcal/kg, p = 0.11). Protein intake was significantly higher in patients (1.4 +/- 0.2 g/kg) than patient-controls (0.9 +/- 0.1 g of protein per kg, p less than 0.05). Despite increased calorie and protein intake, biochemical measures of nutritional status were worse in the patients. Serum albumin was lower in patients (33 +/- 1 g/L) than in patient-controls (37 +/- 1 g/L, p less than 0.05) as was level of hemoglobin (patients: 117 +/- 5; patient-controls: 132 +/- 5 g/L, p less than 0.05). Patients with stage IV (severe) sores had lower serum cholesterol levels (3.46 +/- 0.31 mmol/L, n = 5) than patients with stage II/III (milder) sores (4.58 +/- 0.23 mmol/L, n = 9, p less than 0.05). Plasma zinc was low in both patients (11.2 +/- 0.6 mumol/L) and patient-controls (11.5 +/- 0.7 mumol/L, p = NS). Pressure sore surface area was positively correlated with calorie intake per kilogram of body weight (r = +0.59, p less than 0.04) and negatively correlated with body mass index (r = -0.70, p less than 0.03), hemoglobin (r = -0.55, p less than 0.07) and serum cholesterol (r = -0.57, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Effectiveness of individualized long-term therapy with niacin and probucol in reduction of serum cholesterol

A retrospective analysis was made of the results of the individualized office management of hypercholesterolemia in 37 patients (25 male, 12 female) with severe atherosclerosis (n = 35) or a predisposition to it (n = 2). The effects of diet instruction, diet and a niacin supplement, and diet plus the niacin supplement and probucol were assessed. Diet alone (n = 37) was prescribed for an average of 4.8 years; diet plus niacin (n = 37) for an average of 2.0 years; and diet plus niacin and probucol (n = 19) for an average of 2.9 years. Each patient served as his or her own control. The maximum serum cholesterol at the beginning of the diet period was 8.69 +/- 2.15 mmol/L (336 +/- 83 mg/dL) (mean plus or minus standard deviation; n = 37). The goal cholesterol was less than 5.20 mmol/L (200 mg/dL). On diet alone the cholesterol level fell to 7.21 +/- 1.27 mmol/L (279 +/- 49 mg/dL) (P less than .001); and goal cholesterol was reached by 12 of 37 patients (32.4 percent), but was maintained in none. On adding niacin, the mean cholesterol fell to 6.21 +/- 1.16 mmol/L (240 +/- 45 mg/dL) (P less than .001). The goal cholesterol was reached in 22 of 37 patients (59.4 percent), but was maintained in only 7 of 37 (18.9 percent). Nineteen of 37 patients on diet plus niacin also received probucol. Goal cholesterol was reached in 14 of 19 patients (73.6 percent), and was maintained in 11 of 19 (57.9 percent).(ABSTRACT TRUNCATED AT 250 WORDS)     

An oat-containing hypocaloric diet reduces systolic blood pressure and improves lipid profile beyond effects of weight loss in men and women

Hypertension, dyslipidemia and overweight contribute substantially to cardiovascular disease risk. One of the most effective methods for improving high blood pressure and lipid profiles is loss of excess weight. Other recommendations for reducing cardiovascular risk include changes in dietary micronutrient, macronutrient and fiber intakes. To better define a diet for reduction in cardiovascular risk, 43 adults (body mass index 26.4 +/- 3.3, range 20.5-33.9 kg/m(2)) participated in an 8-wk study to determine the effects of two diets on weight, blood pressure, lipids and insulin sensitivity. For 2 wk, weight was maintained and all subjects consumed a control diet. For the next 6 wk, subjects consumed one of two hypocaloric diets (maintenance energy minus 4.2 MJ/d): the control diet (n = 21) or a diet containing oats [45 g/(4.2 MJ dietary energy. d), n = 22]. There was no significant difference between groups in changes in weight loss (control -4.0 +/- 1.1 kg, oats -3.9 +/- 1.6 kg, P = 0.8). The oats diet resulted in greater decreases in mean systolic blood pressure (oats -6 +/- 7 mm Hg, control -1 +/- 10 mm Hg, P = 0.026), whereas diastolic blood pressure change did not differ between the two groups (oats -4 +/- 6 mm Hg, control -3 +/- 5 mm Hg, P = 0.8). The oat diet resulted in significantly greater decreases in total cholesterol (oats -0.87 +/- 0.47 mmol/L, control -0.34 +/- 0.5 mmol/L, P = 0.003) and LDL cholesterol (oats -0.6 +/- 0.41 mmol/L, control -0.2 +/- 0.41mmol/L, P = 0.008). In summary, a hypocaloric diet containing oats consumed over 6 wk resulted in greater improvements in systolic blood pressure and lipid profile than did a hypocaloric diet without oats.     

Introducing a new component of the metabolic syndrome: low cholesterol absorption

BACKGROUND: Weight reduction is the recommended treatment of obese type 2 diabetes, but the effects of weight reduction on cholesterol metabolism are poorly understood. OBJECTIVE: We investigated glucose, cholesterol, and lipoprotein metabolism at baseline and 2 y after weight reduction in obese patients with type 2 diabetes consuming an isoenergetic diet. DESIGN: Sixteen subjects were randomly chosen to consume a very-low-energy or low-energy diet for 3 mo, after which they consumed a weight-maintenance diet for up to 2 y. Cholesterol absorption and metabolism, LDL and HDL kinetics, and variables of glucose metabolism were studied at baseline and 2 y. RESULTS: Baseline serum sex hormone binding globulin (SHBG) was significantly related to cholesterol absorption efficiency, and serum glucose and insulin concentrations were associated with cholesterol synthesis. After 2 y, body weight was reduced by 6 +/- 1 kg (P < 0.01), body mass index by 6% (P < 0.05), and blood glucose by 14% (P < 0.01); the ratio of serum SHBG to insulin increased by 66% (P < 0.05). Serum and VLDL, LDL, and HDL triacylglycerol were significantly reduced by 13-24%. Despite unchanged serum concentrations of cholesterol, cholesterol absorption efficiency and the ratio of serum plant sterols to cholesterol-indicators of cholesterol absorption-increased by 28% (P < 0.01) and 20-31% (P < 0. 05 for both), respectively; the fractional removal of LDL apolipoprotein B decreased. Fecal excretion of cholesterol as neutral sterols decreased significantly by 11%. Changes in body weight were significantly negatively correlated with changes in ratios of cholesterol to serum plant sterols and cholestanol. CONCLUSIONS: Baseline cholesterol absorption and synthesis were related to respective serum SHBG, glucose, and insulin values. Weight reduction increased cholesterol absorption and improved variables of glucose metabolism. These results suggest that low cholesterol absorption and high synthesis may be part of the insulin resistance syndrome.     

Acute effect of high-calcium milk with or without additional magnesium,or calcium phosphate on parathyroid hormone and biochemical markers of bone resorption

OBJECTIVE: To assess whether there are any differences in the postprandial physiological responses to apple drink (control), calcium phosphate (tricalcium phosphate, TCP) and high-calcium skim milk (HCSM) with or without additional magnesium in postmenopausal women. DESIGN: Randomized, controlled, cross-over. Measurements after overnight fast before each drink, and subsequently every hour for 8 h postprandially. SETTING: Human Nutrition Studies Laboratory, Milk and Health Research Centre, Massey University, Palmerston North, New Zealand. SUBJECTS: Twenty-one healthy postmenopausal women. INTERVENTION: Four drinks, each 400 ml. (1) Apple drink (25% fruit juice). (2) TCP dispersed in water containing 1200 mg Ca. (3) HCSM containing 1200 mg Ca and 65.5 mg Mg. (4) HCSM containing 1200 mg Ca and 172 mg Mg. RESULTS: There was no difference in baseline serum calcium, PTH or C-telopeptide levels between drinks. There were no overall differences in serum calcium after apple or after either milk, but after TCP serum calcium increased from a baseline value of 2.12+/-0.08 to a mean peak of 2.21+/-0.12 mmol/l (s.d.) (P=0.0001) after 2 h. There were no significant differences in serum PTH after either apple or HCSM+Mg. In contrast, after TCP, serum PTH decreased from 2.76+/-0.69 to a mean nadir of 2.23+/-0.65 pmol/l (P=0.0001) after 1 h, and after HCSM, it decreased from 2.71+/-0.78 to a mean nadir of 2.51+/-0.87 pmol/l (P=0.007) after 2 h. Serum C-telopeptides decreased after each drink, reaching nadirs after 5 h. At this time the serum values for each of the high calcium drinks were not different from each other, but were significantly less than for apple (P=0.001 for each), being 0.22+/-0.09 ng/ml for apple, 0.15+/-0.08 for TCP, 0.14+/-0.07 for HCSM and 0.16+/-0.07 for HCSM+Mg. CONCLUSION: Despite differences in serum calcium and PTH responses to the three high-calcium drinks that we tested, there was no distinguishable difference in serum C-telopeptides between high calcium drinks.     

Effect of an energy-restricted, high-protein, low-fat diet relative to a conventional high-carbohydrate, low-fat diet on weight loss, body composition, nutritional status, and markers of cardiovascular health in obese women

BACKGROUND: Limited evidence suggests that a higher ratio of protein to carbohydrate during weight loss has metabolic advantages. OBJECTIVE: The objective was to evaluate the effects of a diet with a high ratio of protein to carbohydrate during weight loss on body composition, cardiovascular disease risk, nutritional status, and markers of bone turnover and renal function in overweight women. DESIGN: The subjects were randomly assigned to 1 of 2 isocaloric 5600-kJ dietary interventions for 12 wk according to a parallel design: a high-protein (HP) or a high-carbohydrate (HC) diet. RESULTS: One hundred women with a mean (+/-SD) body mass index (in kg/m(2)) of 32 +/- 6 and age of 49 +/- 9 y completed the study. Weight loss was 7.3 +/- 0.3 kg with both diets. Subjects with high serum triacylglycerol (>1.5 mmol/L) lost more fat mass with the HP than with the HC diet (x +/- SEM: 6.4 +/- 0.7 and 3.4 +/- 0.7 kg, respectively; P = 0.035) and had a greater decrease in triacylglycerol concentrations with the HP (-0.59 +/- 0.19 mmol/L) than with the HC (-0.03 +/- 0.04 mmol/L) diet (P = 0.023 for diet x triacylglycerol interaction). Triacylglycerol concentrations decreased more with the HP (0.30 +/- 0.10 mmol/L) than with the HC (0.10 +/- 0.06 mmol/L) diet (P = 0.007). Fasting LDL-cholesterol, HDL-cholesterol, glucose, insulin, free fatty acid, and C-reactive protein concentrations decreased with weight loss. Serum vitamin B-12 increased 9% with the HP diet and decreased 13% with the HC diet (P < 0.0001 between diets). Folate and vitamin B-6 increased with both diets; homocysteine did not change significantly. Bone turnover markers increased 8-12% and calcium excretion decreased by 0.8 mmol/d (P < 0.01). Creatinine clearance decreased from 82 +/- 3.3 to 75 +/- 3.0 mL/min (P = 0.002). CONCLUSION: An energy-restricted, high-protein, low-fat diet provides nutritional and metabolic benefits that are equal to and sometimes greater than those observed with a high-carbohydrate diet.     

Toward improved management of NIDDM: A randomized, controlled, pilot intervention using a lowfat, vegetarian diet.

OBJECTIVE: To investigate whether glycemic and lipid control in patients with non-insulin-dependent diabetes (NIDDM) can be significantly improved using a low-fat, vegetarian (vegan) diet in the absence of recommendations regarding exercise or other lifestyle changes. METHODS: Eleven subjects with NIDDM recruited from the Georgetown University Medical Center or the local community were randomly assigned to a low-fat vegan diet (seven subjects) or a conventional low-fat diet (four subjects). Two additional subjects assigned to the control group failed to complete the study. The diets were not designed to be isocaloric. Fasting serum glucose, body weight, medication use, and blood pressure were assessed at baseline and biweekly thereafter for 12 weeks. Serum lipids, glycosylated hemoglobin, urinary albumin, and dietary macronutrients were assessed at baseline and 12 weeks. RESULTS: Although the sample was intentionally small in accordance with the pilot study design, the 28% mean reduction in fasting serum glucose of the experimental group, from 10.7 to 7.75 mmol/L (195 to 141 mg/dl), was significantly greater than the 12% decrease, from 9.86 to 8.64 mmol/L (179 to 157 mg/dl), for the control group (P < 0.05). The mean weight loss was 7.2 kg in the experimental group, compared to 3. 8 kg for the control group (P < 0.005). Of six experimental group subjects on oral hypoglycemic agents, medication use was discontinued in one and reduced in three. Insulin was reduced in both experimental group patients on insulin. No patient in the control group reduced medication use. Differences between the diet groups in the reductions of serum cholesterol and 24-h microalbuminuria did not reach statistical significance; however, high-density lipoprotein concentration fell more sharply (0.20 mmol/L) in the experimental group than in the control group (0.02 mmol/L) (P < 0.05). CONCLUSION: The use of a low-fat, vegetarian diet in patients with NIDDM was associated with significant reductions in fasting serum glucose concentration and body weight in the absence of recommendations for exercise. A larger study is needed for confirmation.     

Cholesterol-lowering effect of skim milk from immunized cows in hypercholesterolemic patients

The effect of skim milk from cows immunized against a variety of human intestinal bacteria on serum cholesterol concentrations was examined in 11 patients with primary hypercholesterolemia in a 24-wk, randomized, double-blind, placebo-controlled, crossover study. After a 4-wk baseline period, patients were treated for 8 wk either with skim milk from immunized cows (active) or with control skim milk (placebo) followed by an 8-wk period with the treatment order reversed. Eight weeks of active treatment with skim milk from immunized cows reduced serum total cholesterol concentrations by 0.52 +/- 0.59 mmol/L (mean +/- SD; P less than 0.025), or 8%, LDL cholesterol by 0.16 +/- 0.59 mmol/L (NS), or 4%, and the atherogenic index (total cholesterol/HDL cholesterol) by 0.42 +/- 1.85 (P less than 0.05), or 8%, compared with the placebo treatment. Reversal of the favorable development occurred upon cessation of active treatment. We conclude that daily supplementation of a normal diet with skim milk from immunized cows can result in a significant reduction of elevated blood cholesterol concentrations.     

Alterations of lipid and cholesterol metabolism in cachectic tumor-bearing rats are prevented by insulin

The ascites hepatoma Yoshida AH130 causes in the host a rapid and progressive body weight loss, associated with reduced food intake, and protein and lipid hypercatabolism. Because insulin regulates glucose as well as lipid and protein metabolism, we suggest that the observed alterations are at least in part secondary to hypoinsulinemia and/or to the increase of counterregulatory hormones in AH130-bearing rats. To verify this hypothesis, controls with free access to food (n = 4), controls with free access to food plus insulin (107 micromol. kg body wt-1. d-1) (n = 4), controls pair-fed to the tumor-bearing rats (n = 4), pair-fed controls treated with insulin (n= 4), tumor hosts (n = 9), and tumor hosts treated with insulin (n = 6) were used. The Yoshida ascites hepatoma cells ( approximately 10(8) cells/rat) were inoculated intraperitoneally. Daily food intake and body weight were measured; insulin was injected starting the day of tumor implantation for 6 d. The metabolism of both cholesterol and lipids was investigated in tumor cells, and ascitic fluid and blood serum were investigated at the end of treatment. Insulin prevented the reduction of food intake (19 +/- 0.6 vs. 13 +/- 0.4 g/d, P < 0.01; AH130 hosts treated and not treated with insulin, respectively), the loss of body weight (202 +/- 12 vs. 135 +/- 9 g, P < 0.01), lowered the circulating triglycerides (48.3 +/- 4.9 vs. 84.5 +/- 7.1 mmol/L, P < 0.01), and free fatty acids (561 +/- 47 vs. 989 +/- 54 mmol/L (P < 0.01), while corrected the decrease of adipose lipoprotein lipase activity (1,240 +/- vs. 300 +/- pmol FA, P < 0.01) observed in AH130 hosts. Moreover, insulin prevented the decrease in HDL cholesterol (13.2 +/- 0.8 vs. 9.3. +/- 0.7 mmol/L, P < 0.01) and significantly increased hepatic cholesterol synthesis as evaluated by 14C-acetate incorporation into cholesterol, in both liver (3,337 +/- 245 vs. 830 +/- 115 Bq/g, P < 0.01) and AH130 cells (11,676 +/- 1,693 vs. 4,196 +/- 527 Bq/10(6) cells, P < 0.01). Thus insulin treatment ameliorated many metabolic derangements, with a lengthening of rats survival time (7 +/- 1 vs. 11 +/- 1 d, P < 0.05) without significantly stimulating tumor growth. These data, together with our previous observations on the effectiveness of insulin on protein turnover perturbations, suggest that many metabolic alterations occurring during cancer cachexia can be avoided by the administration of this hormone.     

Effects of guar gum in male subjects with hypercholesterolemia

Fourteen male subjects with hypercholesterolemia received daily supplementation with granulated guar gum or placebo, 15 g/day, during 12 wk in a double-blind, cross-over trial. A statistically significant reduction in serum total cholesterol (7.27 +/- 0.24 versus 8.23 +/- 0.26 mmol/l, mean +/- SEM, p less than 0.01) which was mainly due to a reduction in low-density lipoprotein cholesterol concentration (4.70 +/- 0.19 versus 5.32 +/- 0.23 mmol/l, p less than 0.05) was observed after 6 wk on guar gum as compared with placebo. Between 6 and 12 wk on guar gum the serum cholesterol and low-density lipoprotein cholesterol levels increased in most subjects, and after 12 wk the difference from placebo was no longer statistically significant. Serum high-density lipoprotein cholesterol levels were unaffected by guar gum. Serum and lipoprotein triglycerides showed no significant changes during the study, and the body weight of the subjects remained unchanged. Serum calcium, magnesium, phosphate, and iron levels, and urinary calcium excretion were not affected by guar gum supplementation. No severe side effects were observed, necessitating reduction of the dose or stopping the treatment. It is concluded that the hypocholesterolemic effect of guar gum seems to decrease during prolonged dietary supplementation. Further controlled studies are needed before the dose response and the long-term effects of guar gum in hypercholesterolemia can be evaluated.