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No difference in the satiety effect of disguised preloads with the same energy, volume and palatability but containing only proteins, carbohydrates or lipids
Abstracts / Appetite 52 (2009) 815–868
Noradrenergic neurons of the area postrema mediate amylin’s anorectic action C.S. POTES ∗ , T. RIEDIGER, T.A. LUTZ Institute of Veterinary Physiology, Zurich Center for Integrative Human Physiology, Zurich University, Zurich, Switzerland Peripheral amylin inhibits food intake via activation of the area postrema (AP). 59% of amylin-activated AP neurons are noradrenergic (NA), i.e., they express dopamine-beta-hydroxylase (DBH). Here, we wanted to test whether AP NA neurons mediate amylin’s anorectic effect. We performed a specific lesion of AP NA neurons using a saporin conjugated to an antibody against DBH (DSAP). IgG-saporin was used in sham controls. After 2–3 weeks necessary for neuronal degeneration, we tested the rats for the effect of amylin (5 or 20 g/kg BW, s.c.) to reduce food intake. In a terminal experiment, the rats received amylin (20 g/kg) or saline; brain sections with the AP and nucleus of the solitary tract (NTS) were stained for DBH to assess lesion success and for c-Fos expression to evaluate amylin-induced neuronal activation. DBH staining revealed that 10 DSAP-injected rats had NA lesion equal to or above 50%, defined as successful; 6 had lesions below 50%. Daily food intake and body weight gain did not differ between lesioned and sham groups. Amylin-induced anorexia was observed in sham rats with both amylin doses, while rats with a successful lesion had no significant reduction in eating after either amylin dose. Rats with lesions below 50% only ate less after the higher amylin dose. In contrast to sham-lesioned animals, successfully NA-lesioned rats did not show amylin-induced c-Fos expression in the AP and NTS. These results provide first evidence for a functional role of NA neurons in the AP in the mediation of amylin’s anorectic effect. doi:10.1016/j.appet.2009.04.158
No difference in the satiety effect of disguised preloads with the same energy, volume and palatability but containing only proteins, carbohydrates or lipids M. POTIER 1,∗ , G. FROMENTIN 1 , A. LESDEMA 1 , R. BENAMOUZIG 1 , C. MARTIN-ROUAS 2 , D. TOME 3 , A. MARSSET-BAGLIERI 3 1 INRA, CNRH-IdF, UMR914 Nutrition Physiology and Ingestive Behavior, Paris, France 2 SB Alliance – Direction de la Stratégie Produits, Viroflay, France 3 AgroParisTech, CNRH-IdF, UMR914 Nutrition Physiology and Ingestive Behavior, Paris, France Protein as the macronutrient with the highest satiety effect is still matter of debate because of the diversity of designs employed. The aim of this study was to compare the effect on satiety of different preloads constituted only by protein, fat or carbohydrate in very controlled conditions (iso-palatabilty, -energy, -volumetry). 56 subjects participated to 4 randomised test days, one day per macronutrient and a control day. In each test day, they had to consume the preload entirely and their food intake was measured during the next meals. The volunteers were separated in 2 groups: the first one (T0) consumed the preload immediately before lunch and the second one (T1) 1 h before. Whatever the delay, no difference was found on food intake at lunch between the 3 preloads. In the T1 group, energy intake of preload and lunch was higher after lipid preload than in the control. In the T0 group, the same result was observed with lipids but also with proteins. We did not observe an effect of the delay between preload and test-meal. Our results do not confirm the highest satiety effect of proteins, may be because we used unusual foods as preloads. According to the concept of learned satiety, the results could not be the same if the subjects were previously familiarised to the preloads. doi:10.1016/j.appet.2009.04.159
853
The consumption of a portion of cheese as first course of a meal does not impact meal and daily food intake M. POTIER 1,∗ , G. FROMENTIN 1 , R. BENAMOUZIG 1 , D. TOME 2 , A. MARSSET-BAGLIERI 2 1 INRA, CNRH-IdF, UMR914 Nutrition Physiology and Ingestive Behavior, Paris, France 2 AgroParisTech, CNRH-IdF, UMR914 Nutrition Physiology and Ingestive Behavior, Paris, France The consumption of cheese at the end of a meal (whereas we are no longer hungry) is often described as extra-energy ingested, promoting overweight. However, cheeses present nutritional qualities like a great amount of calcium. We wondered if consuming cheese at first course of meals could permit to benefit from their nutritional qualities while preventing over energy consumption, since in this case energy brought by cheese would be immediately taken into account in first pre-absorptive satiety signals. 37 women (33.8 ± 1.6 years; BMI = 21.0 ± 0.3 kg/m2 ) participated to 4 randomised test days corresponding to 3 different portions of cheese and a control day. The 3 cheeses were a portion of 30 g (80 kcal) of camembert cheese, and portions of 30 g (80 kcal) or 75 g (200 kcal) of light pressed cheese. In each test day, the subjects had to consume the cheese at the beginning of lunch and their food intake was measured during the next meals (lunch, collation and dinner). No difference of energy intake was found between control and test days both at lunch and on the whole day. Moreover, neither the composition nor the quantity of cheese affected energy intake since there was no difference between the 3 test days. These results show that consuming a portion of cheese at first course of a meal does not promote over energy consumption and could be a mean to increase intake of diary products without negative effect on weight management. doi:10.1016/j.appet.2009.04.160
Effects of intermittent intraperitoneal infusion of exendin-4 and PYY(3–36) on food intake and adiposity in diet-induced obese rats R.D. REIDELBERGER 1,2,∗ , A.C. HAVER 1,2 1 DVA-NWIHCS, Omaha, NE, USA 2 Creighton University, Omaha, NE, USA Our aim was to determine whether intermittent IP infusion of exendin-4 can produce a sustained reduction in daily food intake, body weight and adiposity in diet-induced obese rats. Rats (641 ± 9 g, 143 ± 5 g fat) with intraperitoneal catheters tethered to infusion swivels and programmable pumps had free access to a 45% fat diet. Food intake was measured by continuous computer recording of changes in food bowl weight. Body fat was measured by quantitative nuclear magnetic resonance. Vehicle-treated rats (n = 24) had a stable food intake, body weight and adiposity during the 8-week study. Two, 3-h infusions of exendin-4 (20 pmol/h) at the beginning and end of the dark period each day in a second group of rats (n = 24) produced a sustained 19 ± 1% decrease in daily food intake for 14 days, and a 5% and 18% decrease in body weight and adiposity, respectively. Loss in efficacy of exendin-4 appeared to be due to activation of a homeostatic response to increase food intake when energy reserves declined. Subsequent co-infusion of PYY(3–36) (240 pmol/h) and exendin-4 (20 pmol/h) restored the inhibitory effect of exendin-4 on daily food intake. Together they produced a sustained 22 ± 1% reduction in daily food intake for 20 days, and a further decrease in body weight and adiposity of 6% and 16%, respectively. Thus, chronic intermittent IP infusion of exendin4 alone and in combination with PYY(3–36) can produce a relatively prolonged reduction in daily food intake, body weight and adiposity in diet-induced obese rats. doi:10.1016/j.appet.2009.04.161
Noradrenergic neurons of the area postrema mediate amylin’s anorectic action C.S. POTES ∗ , T. RIEDIGER, T.A. LUTZ Institute of Veterinary Physiology, Zurich Center for Integrative Human Physiology, Zurich University, Zurich, Switzerland Peripheral amylin inhibits food intake via activation of the area postrema (AP). 59% of amylin-activated AP neurons are noradrenergic (NA), i.e., they express dopamine-beta-hydroxylase (DBH). Here, we wanted to test whether AP NA neurons mediate amylin’s anorectic effect. We performed a specific lesion of AP NA neurons using a saporin conjugated to an antibody against DBH (DSAP). IgG-saporin was used in sham controls. After 2–3 weeks necessary for neuronal degeneration, we tested the rats for the effect of amylin (5 or 20 g/kg BW, s.c.) to reduce food intake. In a terminal experiment, the rats received amylin (20 g/kg) or saline; brain sections with the AP and nucleus of the solitary tract (NTS) were stained for DBH to assess lesion success and for c-Fos expression to evaluate amylin-induced neuronal activation. DBH staining revealed that 10 DSAP-injected rats had NA lesion equal to or above 50%, defined as successful; 6 had lesions below 50%. Daily food intake and body weight gain did not differ between lesioned and sham groups. Amylin-induced anorexia was observed in sham rats with both amylin doses, while rats with a successful lesion had no significant reduction in eating after either amylin dose. Rats with lesions below 50% only ate less after the higher amylin dose. In contrast to sham-lesioned animals, successfully NA-lesioned rats did not show amylin-induced c-Fos expression in the AP and NTS. These results provide first evidence for a functional role of NA neurons in the AP in the mediation of amylin’s anorectic effect. doi:10.1016/j.appet.2009.04.158
No difference in the satiety effect of disguised preloads with the same energy, volume and palatability but containing only proteins, carbohydrates or lipids M. POTIER 1,∗ , G. FROMENTIN 1 , A. LESDEMA 1 , R. BENAMOUZIG 1 , C. MARTIN-ROUAS 2 , D. TOME 3 , A. MARSSET-BAGLIERI 3 1 INRA, CNRH-IdF, UMR914 Nutrition Physiology and Ingestive Behavior, Paris, France 2 SB Alliance – Direction de la Stratégie Produits, Viroflay, France 3 AgroParisTech, CNRH-IdF, UMR914 Nutrition Physiology and Ingestive Behavior, Paris, France Protein as the macronutrient with the highest satiety effect is still matter of debate because of the diversity of designs employed. The aim of this study was to compare the effect on satiety of different preloads constituted only by protein, fat or carbohydrate in very controlled conditions (iso-palatabilty, -energy, -volumetry). 56 subjects participated to 4 randomised test days, one day per macronutrient and a control day. In each test day, they had to consume the preload entirely and their food intake was measured during the next meals. The volunteers were separated in 2 groups: the first one (T0) consumed the preload immediately before lunch and the second one (T1) 1 h before. Whatever the delay, no difference was found on food intake at lunch between the 3 preloads. In the T1 group, energy intake of preload and lunch was higher after lipid preload than in the control. In the T0 group, the same result was observed with lipids but also with proteins. We did not observe an effect of the delay between preload and test-meal. Our results do not confirm the highest satiety effect of proteins, may be because we used unusual foods as preloads. According to the concept of learned satiety, the results could not be the same if the subjects were previously familiarised to the preloads. doi:10.1016/j.appet.2009.04.159
853
The consumption of a portion of cheese as first course of a meal does not impact meal and daily food intake M. POTIER 1,∗ , G. FROMENTIN 1 , R. BENAMOUZIG 1 , D. TOME 2 , A. MARSSET-BAGLIERI 2 1 INRA, CNRH-IdF, UMR914 Nutrition Physiology and Ingestive Behavior, Paris, France 2 AgroParisTech, CNRH-IdF, UMR914 Nutrition Physiology and Ingestive Behavior, Paris, France The consumption of cheese at the end of a meal (whereas we are no longer hungry) is often described as extra-energy ingested, promoting overweight. However, cheeses present nutritional qualities like a great amount of calcium. We wondered if consuming cheese at first course of meals could permit to benefit from their nutritional qualities while preventing over energy consumption, since in this case energy brought by cheese would be immediately taken into account in first pre-absorptive satiety signals. 37 women (33.8 ± 1.6 years; BMI = 21.0 ± 0.3 kg/m2 ) participated to 4 randomised test days corresponding to 3 different portions of cheese and a control day. The 3 cheeses were a portion of 30 g (80 kcal) of camembert cheese, and portions of 30 g (80 kcal) or 75 g (200 kcal) of light pressed cheese. In each test day, the subjects had to consume the cheese at the beginning of lunch and their food intake was measured during the next meals (lunch, collation and dinner). No difference of energy intake was found between control and test days both at lunch and on the whole day. Moreover, neither the composition nor the quantity of cheese affected energy intake since there was no difference between the 3 test days. These results show that consuming a portion of cheese at first course of a meal does not promote over energy consumption and could be a mean to increase intake of diary products without negative effect on weight management. doi:10.1016/j.appet.2009.04.160
Effects of intermittent intraperitoneal infusion of exendin-4 and PYY(3–36) on food intake and adiposity in diet-induced obese rats R.D. REIDELBERGER 1,2,∗ , A.C. HAVER 1,2 1 DVA-NWIHCS, Omaha, NE, USA 2 Creighton University, Omaha, NE, USA Our aim was to determine whether intermittent IP infusion of exendin-4 can produce a sustained reduction in daily food intake, body weight and adiposity in diet-induced obese rats. Rats (641 ± 9 g, 143 ± 5 g fat) with intraperitoneal catheters tethered to infusion swivels and programmable pumps had free access to a 45% fat diet. Food intake was measured by continuous computer recording of changes in food bowl weight. Body fat was measured by quantitative nuclear magnetic resonance. Vehicle-treated rats (n = 24) had a stable food intake, body weight and adiposity during the 8-week study. Two, 3-h infusions of exendin-4 (20 pmol/h) at the beginning and end of the dark period each day in a second group of rats (n = 24) produced a sustained 19 ± 1% decrease in daily food intake for 14 days, and a 5% and 18% decrease in body weight and adiposity, respectively. Loss in efficacy of exendin-4 appeared to be due to activation of a homeostatic response to increase food intake when energy reserves declined. Subsequent co-infusion of PYY(3–36) (240 pmol/h) and exendin-4 (20 pmol/h) restored the inhibitory effect of exendin-4 on daily food intake. Together they produced a sustained 22 ± 1% reduction in daily food intake for 20 days, and a further decrease in body weight and adiposity of 6% and 16%, respectively. Thus, chronic intermittent IP infusion of exendin4 alone and in combination with PYY(3–36) can produce a relatively prolonged reduction in daily food intake, body weight and adiposity in diet-induced obese rats. doi:10.1016/j.appet.2009.04.161