Effect of milk protein intake and casein-to-whey ratio in breakfast meals on postprandial glucose, satiety ratings, and subsequent meal intake.

Whey and casein proteins differentially affect postprandial blood glucose and satiety mechanisms, with relevance for type 2 diabetes and obesity. Therefore, the purpose of this work was to investigate the effect of the casein-to-whey protein ratio and total protein concentration of milks consumed with cereal on postprandial blood glucose, appetite ratings, and subsequent food intake in a randomized, controlled, double-blinded study with healthy young adults (n = 32, 23.4 ± 3.1 yr, body mass index = 22.2 ± 2.5 kg/m2). Fasted participants consumed milk (250 mL) with either 80:20 or 40:60 (modified) casein-to-whey protein ratios at commercially normal (3.1%, wt) or high protein (9.3%, wt) concentration, or control (water with whey permeate), each along with 2 servings of oat-based breakfast cereal. Blood glucose concentrations were determined from finger prick blood samples and appetite was assessed using visual analog scales. Participants consumed a measured ad libitum pizza lunch at 120 min and blood glucose determination and appetite assessment continued following the lunch meal (140-200 min) to observe the second meal effect. Pre-lunch (0-120 min) incremental area under the curve (iAUC) and mean change from baseline blood glucose were reduced with consumption of all milk treatments relative to control. However, we found no differences between all treatments on pre-lunch appetite change from baseline and total area under the curve (tAUC) or lunch meal food intake. In terms of protein concentration results, high protein (9.3%, wt) treatments contrasted to normal protein (3.1%, wt) treatments lowered blood glucose change from baseline and iAUC, and post-lunch appetite change from baseline and tAUC. Protein ratio showed a modest effect in that modified (40:60) protein ratio lowered pre-lunch blood glucose change from baseline but not iAUC, and normal (80:20) protein ratio lowered pre-lunch appetite change from baseline but not tAUC. Therefore, high-carbohydrate breakfast meals with increased protein concentration (9.3%, wt) could be a dietary strategy for the attenuation of blood glucose and improved satiety ratings after the second meal.

The effects of potatoes and other carbohydrate side dishes consumed with meat on food intake, glycemia and satiety response in children.

BACKGROUND: The effect of carbohydrate (CHO) foods on blood glucose (BG) is ranked by their glycemic index (GI). Boiled and mashed potatoes (BMPs) are ranked as high GI foods, whereas pasta and rice have moderate GI rankings. The objective of this study was to compare ad libitum consumption of common CHO dishes consumed with meat on meal-time food intake and post-meal satiety, BG, insulin and gut hormones in 11- to 13-year-old normal weight children. METHODS: Two randomized crossover studies were conducted. At weekly intervals, children (experiment 1: 12 males (M), 8 females (F); experiment 2: 6M, 6 F) received in random order 1 of 5 CHO side dishes of rice, pasta, BMP, fried French fries (FFF) or baked French fries (BFF) eaten freely together with a fixed amount of lean beef (100 g). In experiment-1, food intake over 30 min and subjective appetite were measured for 120 min. In experiment-2, the same outcomes were measured along with BG, plasma insulin and gut hormones. RESULTS: The results for boys and girls were pooled as sex was not a factor. In both experiments, children consumed 30-40% less calories at meals with BMP (P<0.0001) compared with all other treatments, which were similar. BMP increased satiety, expressed as a change in appetite per kilocalorie, more than all other treatments (P<0.0001). FFF resulted in the lowest (P<0.0001) glucose and insulin at meal end and post-meal and peptide YY (PYY) post-meal. Blood measures were similar among all other treatments. CONCLUSIONS: The physiological functions of CHO foods consumed ad libitum at meal time on food intake, appetite, BG, insulin and gut hormone responses in children is not predicted by the GI.

A comparison of effects of lard and hydrogenated vegetable shortening on the development of high-fat diet-induced obesity in rats.

BACKGROUND: Obesity is associated with increased consumption and preference for dietary fat. Experimental models of fat-induced obesity use either lard or vegetable shortening. Yet, there are no direct comparisons of these commonly used fat sources, or the influence of their fatty acid composition, on the development of diet-induced obesity. OBJECTIVE: To compare the effects of lard and hydrogenated vegetable-shortening diets, which differ in their fatty acid composition, on weight gain and the development of obesity and insulin resistance in rats. METHODS AND DESIGN: Male Wistar rats were fed ad libitum for 14 weeks high-fat diets containing either (1) high vegetable fat (HVF, 60 kcal% from vegetable shortening) or (2) high lard fat (HLF, 60 kcal% from lard). Rats fed normal-fat (NF, 16 kcal% from vegetable shortening) diet served as control. Body weight, food intake, adipose tissue mass, serum 25[OH]D3, glucose, insulin and fatty acid composition of diets were measured. RESULTS: Rats fed either of the two high-fat diets had higher energy intake, weight gain and fat accretion than rats fed normal-fat diet. However, rats fed the HLF diet consumed more calories and gained more weight and body fat with greater increases of 32% in total (158.5±8.2 vs 120.2±6.6 g, P<0.05), 30% in visceral (104.4±5.2 vs 80.3±4.2 g, P<0.05) and 36% in subcutaneous fat mass (54.1±3.6 vs 39.9±3.1 g, P<0.05), compared with rats fed the HVF diet. Higher visceral adiposity was positively correlated with serum insulin (r=0.376, P<0.05) and homeostatic model assessment insulin resistance (r=0.391, P<0.05). CONCLUSION: We conclude that lard-based high-fat diets accentuate the increase in weight gain and the development of obesity and insulin resistance more than hydrogenated vegetable-shortening diets. These results further point to the importance of standardizing fatty acid composition and type of fat used in determining outcomes of consuming high-fat diets.

The role of alginates in regulation of food intake and glycemia: a gastroenterological perspective.

Regulation of food intake through modulation of gastrointestinal responses to ingested foods is an ever-growing component of the therapeutic approaches targeting the obesity epidemic. Alginates, viscous and gel-forming soluble fibers isolated from the cell wall of brown seaweeds and some bacteria, are recently receiving considerable attention because of their potential role in satiation, satiety, and food intake regulation in the short term. Enhancement of gastric distension, delay of gastric emptying, and attenuation of postprandial glucose responses may constitute the basis of their physiological benefits. Offering physical, chemical, sensorial, and physiological advantages over other viscous and gel-forming fibers, alginates constitute promising functional food ingredients for the food industry. Therefore, the current review explores the role of alginates in food intake and glycemic regulation, their underlying modes of action and their potential in food applications.

Effect of sodium alginate addition to chocolate milk on glycemia, insulin, appetite and food intake in healthy adult men.

BACKGROUND/OBJECTIVES: Sodium alginate reduces appetite and glycemia, when consumed in water- and sugar-based drinks. But, its effects when added to other commonly consumed beverages have not been reported. Because chocolate milk (CM) is criticized for raising blood glucose more than unflavored milk, the aim of our study was to investigate the effect of adding a strong-gelling sodium alginate to CM on glycemia, insulinemia, appetite and food intake. SUBJECTS/METHODS: In a randomized crossover design, 24 men (22.9±0.4 years; 22.5±0.3 kg/m(2)) were provided with isovolumetric (325 ml) treatments of CM, 1.25% alginate CM, 2.5% alginate CM or 2.5% alginate solution. Sodium alginate had a ratio of 0.78:1 of mannuronic acid (M) to guluronic acid (G) residues, and was block distributed. Treatments were standardized for lactose, sucrose and calcium content, and provided 120 min before an ad libitum pizza meal during which food intake was measured. Appetite and blood glucose and insulin were measured at baseline and at intervals pre- and post-meal. RESULTS: Addition of 2.5% alginate to CM reduced peak glucose concentrations, at 30 min, by an average of 6% and 13% compared with 1.25% alginate CM (95% confidence intervals (CIs): 0.02-1.08; P=0.037) and CM alone (95% CIs: 0.49-1.55; P=0.000) respectively. Insulin peaks at 30 min were lower by 46% after 2.5% alginate CM relative to CM (95% CIs: 3.49-31.78; P=0.009). Pre-meal appetite was attenuated dose dependently by alginate addition to CM; CM with 2.5% alginate reduced mean appetite by an average of 134% compared with CM alone (95% CIs: 8.87-18.98; P=0.000). However, total caloric intake at the pizza meal did not differ among treatments. CONCLUSIONS: The addition of a strong-gelling sodium alginate to CM decreases pre-meal glycemia, insulinemia and appetite, but not caloric intake at a meal 2 h later, in healthy adult men.

Obesogenic phenotype of offspring of dams fed a high multivitamin diet is prevented by a post-weaning high multivitamin or high folate diet.

BACKGROUND: High multivitamin (10-fold AIN-93G, HV) diets fed during pregnancy to Wistar rats increase characteristics of metabolic syndrome in offspring when weaned to the recommended vitamin (RV) diet. OBJECTIVE: To determine whether the effects of HV gestational diets on obesogenic phenotypes in the offspring arise as a consequence of altered hypothalamic control of feeding behavior and if their increased food intake could be prevented by feeding them HV or high folate (10-fold folate, HFol) diets. METHODS: Male offspring of dams fed HV diet during pregnancy weaned to RV, HV or HFol diets were compared with those born to RV dams and weaned to RV diet for 29 weeks. Food intake over 72 h and body weight were measured bi-weekly and weekly, respectively. Glucose response to a glucose load was measured at 18 weeks post weaning. Hypothalamic gene expression of feeding-related neuropeptides including neuropeptide Y, pro-opiomelanocortin (POMC), insulin receptor, leptin receptor, brain-derived neurotrophic factor (BDNF), receptors for dopamine (DopaR1/2/5) and serotonin (SeroR1A/2A/2C), as well as global DNA methylation and brain and plasma folate concentrations were measured at 29 weeks post weaning. RESULTS: HV or HFol pup diets increased brain and plasma folate concentrations and prevented the increase in food intake (5%, P=0.03), body weight (8%, P=0.0006) and glucose response to a glucose load (36%, P=0.02) found in those fed the RV diet. Expression of anorexigenic POMC (P=0.004) and BDNF (P=0.02) was higher, and DopaR1 was lower (P=0.06) in pups fed the HV diet. The HFol pup diet partially brought BDNF to the control level (P=0.02) and lowered SeroR2A (P=0.008). Expression of other genes was unaffected. Global DNA methylation was similar among the diet groups. CONCLUSION: The obesogenic phenotype in offspring from HV-fed dams is prevented by feeding HV or HFol pup diets, possibly due to post-weaning modulation of food intake regulatory mechanisms.

Regular consumption of pulses for 8 weeks reduces metabolic syndrome risk factors in overweight and obese adults.

Pulses are low in energy density, supporting their inclusion in the diet for the management of risk factors of the metabolic syndrome (MetSyn). The aim of the present study was to describe the effects of frequent consumption (five cups/week over 8 weeks) of pulses (yellow peas, chickpeas, navy beans and lentils), compared with counselling to reduce energy intake by 2093 kJ/d (500 kcal/d), on risk factors of the MetSyn in two groups (nineteen and twenty-one subjects, respectively) of overweight or obese (mean BMI 32·8 kg/m2) adults. Body weight, waist circumference, blood pressure, fasting blood parameters and 24 h food intakes were measured at weeks 1, 4 and 8. Blood glucose, insulin, C-peptide, glucagon-like peptide-1 (GLP-1) and ghrelin were measured after a 75 g oral glucose load at weeks 1 and 8. At week 8, both groups reported reductions in energy intake, waist circumference, systolic blood pressure, glycosylated Hb (HbA1c) and glucose AUC and homeostasis model of insulin resistance (HOMA-IR) following the glucose load (P < 0·05). However, HDL, fasting C-peptide and insulin AUC responses were dependent on diet (P < 0·05). HDL and C-peptide increased by 4·5 and 12·3 %, respectively, in the pulse group, but decreased by 0·8 and 7·6 %, respectively, in the energy-restricted group. Insulin AUC decreased in both females and males on the energy-restricted diet by 24·2 and 4·8 %, respectively, but on the pulse diet it decreased by 13·9 % in females and increased by 27·3 % in males (P < 0·05). In conclusion, frequent consumption of pulses in an ad libitum diet reduced risk factors of the MetSyn and these effects were equivalent, and in some instances stronger, than counselling for dietary energy reduction.

Beta glucan: health benefits in obesity and metabolic syndrome.

Despite the lack of international agreement regarding the definition and classification of fiber, there is established evidence on the role of dietary fibers in obesity and metabolic syndrome. Beta glucan (ß-glucan) is a soluble fiber readily available from oat and barley grains that has been gaining interest due to its multiple functional and bioactive properties. Its beneficial role in insulin resistance, dyslipidemia, hypertension, and obesity is being continuously documented. The fermentability of ß-glucans and their ability to form highly viscous solutions in the human gut may constitute the basis of their health benefits. Consequently, the applicability of ß-glucan as a food ingredient is being widely considered with the dual purposes of increasing the fiber content of food products and enhancing their health properties. Therefore, this paper explores the role of ß-glucans in the prevention and treatment of characteristics of the metabolic syndrome, their underlying mechanisms of action, and their potential in food applications.

The acute effects of a pulse-containing meal on glycaemic responses and measures of satiety and satiation within and at a later meal.

Pulses are low glycaemic foods; however, their effect on satiation is unknown. The objective was to determine the effects of an ad libitum pulse meal on food intake (FI), appetite and blood glucose (BG) before and after a test meal (4 h later) and on FI at the test meal. Males (n 24, 22·8 kg/m2) received one of four treatments or control. The pulse treatments contained pasta and tomato sauce and 44 % of energy from: (1) chickpeas, (2) lentils, (3) navy beans or (4) yellow peas. The control was pasta and tomato sauce (pasta and sauce). FI (satiation) was measured at the treatment meal (0-20 min) and at an ad libitum pizza meal 4 h later. BG and appetite were measured from 0 to 340 min. At the treatment meal, lentils led to lower FI compared to chickpeas and pasta and sauce, whereas navy beans led to lower FI compared to chickpeas. Also, lentils led to lower cumulative FI compared to pasta and sauce. All pulses led to lower BG peak and cumulative area under the curve (AUC; 0-340 min); however, only chickpeas, lentils and navy beans reduced pre-pizza meal BG AUC (0-260 min) relative to pasta and sauce. Chickpeas led to lower post-pizza meal BG AUC (260-340 min) compared to navy beans and yellow peas. Consumption of pulses in a high-glycaemic meal contributes to earlier satiation, lower BG following the meal and after a later meal, but these effects are specific to pulse type and cannot be explained by their glycaemic properties alone.

Effect of drinking compared with eating sugars or whey protein on short-term appetite and food intake.

BACKGROUND: It is hypothesized that a solid form of food or food components suppresses subjective appetite and short-term food intake (FI) more than a liquid form. OBJECTIVE: To compare the effect of eating solid vs drinking liquid forms of gelatin, sucrose and its component mixtures, and whey protein, on subjective appetite and FI in young men. DESIGN AND SUBJECTS: A randomized crossover design was used in three experiments in which the subjects were healthy males of normal weight. Solid and liquid forms of gelatin (6 g) (experiment 1, n=14), sucrose (75 g) and a mixture of 50% glucose/50% fructose (G50:F50) (experiment 2, n=15), and acid and sweet whey protein (50 g) (experiment 3, n=14) were compared. The controls were water (experiments 1 and 3) and calorie-free sweetened water with gelatin (sweet gelatin, experiment 1) or calorie-free sweetened water (sweet control, experiment 2). Subjective average appetite was measured by visual analog scales over 1 h and ad libitum FI was measured 1 h after treatment consumption. RESULTS: Average appetite area under the curve was not different between solid and liquid forms of sugars, but was larger, indicating greater satiety for solid compared with liquid forms of gelatin and sweet, but not acid whey protein. The FI was not different from that of control because of solid or liquid sugars or gelatin treatments. However, both solid and liquid forms of whey protein, with no difference among them, suppressed FI compared with control (P<0.05). CONCLUSION: Macronutrient composition is more important than physical state of foods in determining subjective appetite and FI.

The effect of high multivitamin diet during pregnancy on food intake and glucose metabolism in Wistar rat offspring fed low-vitamin diets post weaning.

Rat offspring born to dams fed a high multivitamin diet (HV) are shown to have increased risks of obesity and metabolic syndrome. We hypothesized that a low-vitamin postweaning diet would enhance these characteristics in offspring born to HV dams. During pregnancy, Wistar rats were fed the AIN-93G diet with or without a 10-fold increase in vitamin content. In Experiment 1, at weaning, males were fed the recommended diet (RV) or a diet with 1/3 the vitamin content (1/3 RV) for 12 weeks. In Experiment 2, males and females were fed the RV diet or 1/6 RV diet for 35 weeks. Body weight was measured on a weekly basis, food intake on a daily basis, and for 1 h after an overnight fast following glucose gavage at 6, 12 and 24 weeks. Blood glucose and insulin responses to an oral glucose load were measured at 30 weeks. Males from HV dams, compared with those from RV dams, gained more weight in Experiment 1 (+7%, P < 0.05) and Experiment 2 (+11%, P < 0.0001), along with higher glucose response (+33%, P < 0.05). The 1/6 RV pup diet led to lower weight gain in males (-16%, P < 0.0001) and females (-13%, P < 0.0005), and lower food intake in males (-9%, P < 0.01) independent of the gestational diet. Females on the 1/6 RV diet and from HV dams had higher 1 h food intake (+36%, P < 0.05) and lower insulin response (-25%, P < 0.05) compared with those from RV dams. Exposure of the offspring to low-vitamin diets did not amplify the expression of the metabolic syndrome observed in those born to dams fed an HV diet.

Multivitamin supplementation during pregnancy alters body weight and macronutrient selection in Wistar rat offspring.

The hypothesis that vitamin content of the diet during gestation alters macronutrient choice, food intake and the expression of serotonin receptors and proopiomelanocortin (POMC) in the hypothalamus of the offspring was investigated. Pregnant Wistar rats (n = 10/group) were fed the AIN-93G diet containing a multivitamin mix at the recommended (RV) content or10-fold higher (high vitamin, HV) content. Male offspring were weaned to a choice of 10% and 60% casein diets. Intake regulation by the serotonergic system was determined by measuring food choice daily for 7 weeks, and following tryptophan (TRP) or mCPP (a serotonin receptor agonist) injections at 4 and 6 weeks post-weaning. mRNA expressions of hypothalamic serotonin receptor and POMC were measured at birth, weaning and sacrifice (7 weeks post-weaning). No differences were found in body weight at birth or weaning. HV offspring had lower food intake for the duration of the study (P < 0.001), and 11% lower body weight (P < 0.05) and 23% lower fat pad mass (P < 0.05) at 7 weeks post-weaning. They selected less protein following 12 h of food deprivation (P < 0.05) and were less responsive to TRP (P = 0.05) and mCPP (P < 0.05) injections at 6 weeks post-weaning. Expressions of mRNA for serotonin receptors 5-HT1A/2A/2C at weaning (P < 0.01) and of POMC at weaning and 7 weeks post-weaning (P < 0.05) were lower. In conclusion, intake of multivitamins above the requirements during pregnancy affected macronutrient choice, food intake and the expression of serotonin receptors and POMC in the hypothalamus.

Multivitamin supplementation of Wistar rats during pregnancy accelerates the development of obesity in offspring fed an obesogenic diet.

OBJECTIVE: The effect of gestational multivitamin supplementation on the development of obesity in rat offspring fed an obesogenic diet was investigated. DESIGN: Pregnant Wistar rats (n=10 per group) were fed the AIN-93G diet with the recommended vitamin (RV) content or a 10-fold increase (high vitamin, HV). At weaning, 10 males and 10 females, from separate dams, and from each gestational diet group were weaned to the liquid obesogenic diet for 48 weeks post-weaning. MEASUREMENTS: Body weight (BW) was measured weekly, and food intake over 24 h was measured once every 3 weeks for 24 weeks. Every 4 weeks, after an overnight fast, food intake over 1 h was measured 30 min after a gavage of water or glucose. An oral glucose tolerance test (OGTT) was carried out every 3-5 weeks. Post-weaning fasting glucose, insulin, ghrelin, glucagon-like peptide 1 (GLP-1), and systolic blood pressure (SBP) were measured. RESULTS: No difference in BW at birth or litter size was observed. Males and females from HV dams gained 17% (P<0.05) and 37% (P<0.001) more BW at 48 weeks post-weaning, and consumed 18% (P=0.07) and 20% (P<0.05) more food. One-hour food intake after water and glucose preloads was 27% (P<0.01) and 34% (P<0.05) higher in males from HV dams. Fasting ghrelin and GLP-1 were 27 and 32% higher in males from HV dams at weaning (P<0.05). Blood glucose response to the OGTT was greater in both males and females from HV dams at 13 weeks post-weaning (P<0.05), and the insulin resistance index was 76 and 43% higher in females from HV dams at 14 and 28 weeks post-weaning (P<0.05). SBP was 23 and 16% higher at 44 weeks post-weaning in male and females (P<0.01). CONCLUSION: High multivitamin intake during pregnancy increases the phenotypic expression of obesity and components of the metabolic syndrome in both female and male rats fed an obesogenic diet.

Recent developments in calcium-related obesity research.

The influence of calcium and dairy food intake on energy balance is the object of a growing scientific literature. This manuscript presents the information discussed by subject experts during a symposium on calcium and obesity, initially planned to document in a comprehensive manner the role of calcium and dairy food on energy balance and body composition. This manuscript is organized into 13 propositions statements which either resume the presentation of an invited speaker or integrate recent developments in calcium-related obesity research. More specifically, the effects of calcium and dairy consumption on body weight and adiposity level, appetite, weight loss intervention outcome, lipid-lipoprotein profile and the risk to develop metabolic syndrome are discussed together with the metabolic mechanisms proposed to explain these effects. Taken together, the observations presented in this manuscript suggest that calcium and dairy food intake can influence many components of energy and fat balance, indicating that inadequate calcium/dairy intake may increase the risk of positive energy balance and of other health problems.

A comparison of short-term appetite and energy intakes in normal weight and obese boys following glucose and whey-protein drinks.

OBJECTIVE: To compare the effect of glucose and whey-protein preloads on satiety and food intake (FI) as affected by time to the next meal and body composition in normal weight (NW) and obese (OB) boys. DESIGN: Cross-sectional clinical intervention study of the effect of caloric preloads on FI control in boys. SUBJECTS: Seventeen NW (body mass index (BMI)=18.9+/-0.5 kg/m(2); age=12.2+/-0.3 years) and 17 OB boys (BMI=25.8+/-0.9 kg/m(2); age=11.4+/-0.3 years) (Experiment 1) and 12 NW boys (BMI=18.6+/-0.6 kg/m(2); age=12.1+/-0.3 years) (Experiment 2). MEASUREMENTS: On three separate mornings and in random order each of the boys consumed a noncaloric sweetened preload, glucose (837 kJ) or whey protein (837 kJ) (Experiment 1) or noncaloric preload, glucose (1.0 g/kg) or whey protein (1.0 g/kg) (Experiment 2) made up to 250 ml with water 2 h after the consumption of a fixed breakfast. Food intake from a pizza meal was measured 30 min (Experiment 1) or 60 min (Experiment 2) later. RESULTS: In Experiment 1, glucose suppressed FI (mean kJ+/-s.e.m.) in NW (3126+/-304) and OB boys (3116+/-286) compared with the control (NW, 4015+/-337 and OB, 3791+/-255). Whey protein suppressed FI in NW, but not in OB boys. Body weight, fat-mass and fat-free mass were positively associated with FI after all treatments in NW, but was not related to FI in OB boys. In Experiment 2, FI was suppressed by whey protein (2683+/-367) more than by glucose (3107+/-294) or the control (3585+/-361). CONCLUSION: NW and OB boys respond differently to whey-protein preloads, with time to next meal a factor in the response to both glucose and protein preloads.

Enhanced food intake regulatory responses after a glucose drink in hyperinsulinemic men.

OBJECTIVE: To determine the effect of hyperinsulinemia on food intake and plasma concentrations of glucose and food intake regulatory hormones in men after a glucose drink. DESIGN: Cross-sectional clinical intervention study of the effect of a glucose drink on food intake regulation. SUBJECTS: Thirty-three normoinsulinemic (NI) (body mass index (BMI)=25.3+/-0.6; age=41.4+/-2.4) and 32 hyperinsulinemic (HI) men (BMI=29.5+/-0.6; age=43.4+/-2.6). MEASUREMENTS: Food intake was measured from a pizza meal 1 h after subjects consumed either a noncaloric sweetened drink or a glucose-containing drink (75 g/300 ml) in random order on two occasions. On another occasion, blood samples were taken every 30 min for 2 h after the glucose drink. RESULTS: Fasting insulin in the HI and NI men was 65+/-3 (mean+/-s.e.m.) and 26+/-1.5 pmol/l, respectively. Food intake at the pizza meal was reduced by the glucose drink (P<0.01), but more so in HI (-9.7+/-4.1 %) than NI men (-5.4+/-3.4 %) (P=0.06). The increase in plasma insulin and cholecystokinin (CCK) after the glucose drink was greater and the plasma concentrations of leptin were higher, and ghrelin and adiponectin were lower in HI men than in NI men (P<0.05). CONCLUSION: These results support epidemiological data suggesting that hyperinsulinemia, at least in the early stages, may provide resistance to weight gain, possibly through physiological mechanisms of food intake control.

Catastrophic failure of the Elite Plus total hip replacement, with a Hylamer acetabulum and Zirconia ceramic femoral head.

We report catastrophic early failure of a cemented total hip replacement comprising a modular femoral component with a Zirconia ceramic head and an acetabular component of cross-linked ultra-high molecular-weight polyethylene (Hylamer). Between 1995 and 1999 we implanted 29 hips in 26 patients with a mean age of 49.2 years. Survivorship analysis in this group revealed a failure rate of 67.6% at five years. All hips which failed did so because of aseptic loosening with progressive osteolysis or radiolucencies. We therefore recommend early and regular review of all patients with this combination of implants and early revision surgery in order to avoid massive bone loss.

The use of a carbon fiber plate for periprosthetic supracondylar femoral fractures.

Operative management of periprosthetic supracondylar femoral fractures in poor-quality bone presents a challenging task for the orthopaedic surgeon. We report our experience with the use of a semirigid carbon fiber-reinforced plate in the treatment of 5 patients, all of whom were elderly women with severe osteoporosis and highly restricted mobility. All 5 of the fractures were sustained after low-energy trauma at least 2 years after primary knee arthroplasty. Except for 1 patient who died of pulmonary embolism, all 4 surviving patients progressed uneventfully to fracture union with good mobility and no residual pain. The use of this method for the treatment of periprosthetic femoral fractures has not been reported previously, and we believe it provides a successful and technically undemanding solution to this difficult problem.

A glucagon-like peptide-1 receptor agonist and an antagonist modify macronutrient selection by rats.

The hypothesis that peripheral glucagon-like peptide-1 (GLP-1) is a regulator of both food intake and macronutrient selection in rats was tested by administration of its antagonist, exendin 9-39, and its agonist, exendin 4. The effect of exendin 9-39 given intraperitoneally (i.p.) on food intake was measured after carbohydrate, protein or fat preloads, and on choice between a protein-free, high carbohydrate (CHO) diet and a high protein, low carbohydrate (PRO) diet. The effect of exendin 4 on selection between the CHO and PRO diets was also investigated. Exendin 9-39 significantly enhanced food intake suppression occurring after glucose, but not after corn oil or albumin preloads. In diet selection studies, exendin 9-39 selectively decreased intake of only the CHO diet. In contrast, exendin 4 decreased intake of only the PRO diet. Thus, we suggest that peripheral GLP-1 plays a role in the regulation of macronutrient selection as well as food intake in rats.

An interaction between hypothalamic glucagon-like peptide-1 and macronutrient composition determines food intake in rats.

Glucagon-like peptide-1 (GLP-1) release in response to food ingestion has been associated with decreased food intake. In the present study, we tested the hypothesis that the feeding response to GLP-1 injection into the hypothalamic paraventricular nucleus (PVN) is influenced by the macronutrient composition of the food consumed. In the first experiment, rats were injected with GLP-1 (0.2 microg) or saline (0.5 microL) in the PVN at dark onset (1800 h), and food intake from a maintenance diet (18% protein) was measured at 1, 2 and 14 h. In Experiment 2, after GLP-1 injection, rats were fed a carbohydrate (protein-free) diet for the first 2 h or gavaged with glucose (1.4 g/5 mL). In Experiment 3, after GLP-1 injection, rats were fed a protein (50%) diet for the first 2 h, or were preloaded with egg albumin (1.0 g). In the last experiment, GLP-1 was given after corn oil gavage (2.4 g). GLP-1 injection resulted in a reduced consumption of the maintenance diet from 2 to 14 h. The decreased food intake from 2 to 14 h after GLP-1 administration occurred after carbohydrate intake, either by meal or preloads, but not after protein intake, either as a meal or preload. A transient interaction of GLP-1 with a corn oil gavage was detected but only in early feeding (0-2 h). We conclude that the effect of GLP-1 injected in the PVN on food intake is influenced by the macronutrient composition of the food consumed. Carbohydrate enhances, protein blocks and corn oil has a transient effect on the suppression of food intake caused by GLP-1 in the PVN.