Dietary selection for lysine by the chick

Broiler chicks were provided choices of synthetic diets (a) adequate or low in lysine, and (b) adequate in or devoid of lysine. In each case, chicks consumed some of each diet offered, but preference was shown for the adequate lysine diet. Growth rates of chicks given choices ranged from 80% of that of chicks fed an adequate lysine diet with no choice for two weeks, then growth rates fell to about 60% of those fed adequate lysine. In another study, chicks were fed a diet devoid of lysine but were offered pure L-lysine HCl in a separate feeder. These chicks selected some of the supplementary lysine, but their body weights were only 68% of the body weight of chicks fed an adequate lysine diet after 21 days. Chicks given a choice of diets prepared with an adequate quantity of either L- or D-lysine preferred with L-lysine diet but did not select sufficient quantity to reach normal growth. These observations indicate that chicks can discern the presence of L-lysine in diets or separately, but will not select sufficient quantity for maximum growth potential. A diet prepared with D-lysine was more acceptable than one completely devoid of lysine, suggesting some sensory recognition for lysine.     

Behavioral and physiologic responses to caloric restriction in mice

The purpose of the review is to highlight the influences of ambient temperature (T(a)) and caloric restriction (CR) on metabolism, cardiovascular function and behavior in mice. Standard vivarium ambient temperatures (T(a)?23 degrees C) are a mild cold stress for mice requiring elevated metabolic rate and food intake. Increasing T(a) into the zone of thermoneutrality (TMN?29-33 degrees C) markedly reduces food intake, metabolic rate, heart rate (HR) and blood pressure in mice. Mice are members of a diverse, yet unique group of homeothermic animals that respond to thermal and energetic challenges by allowing body temperature (T(b)) to fall to less than 31 degrees C, a condition known as torpor. In mice housed at standard T(a), torpor is induced by a single night of fasting or a few days of CR. The mechanisms responsible for initiating torpor are related to reduced caloric availability, but do not require leptin. Mice housed at TMN and subjected to CR exhibit physiologic reductions in metabolic rate and HR, but do not appear to enter torpor. Finally, mice exhibit differential locomotor activity responses during CR that depends on T(a). At standard T(a), mice display increased light-phase home-cage activity with CR. This response is virtually eliminated when CR is performed at TMN. We suggest that researchers using mice to investigate energy homeostasis and cardiovascular physiology carefully consider the influence of T(a) on physiology and behavior.     

Increase of food intake induced by glucagon in the rat

The effect of intraperitoneal administration of saline, glucose (25 mg/100 g b.w.), insulin (0.025 U/100 g b.w.) and glucagon (50 micrograms/kg b.w.) on glycemia, liver glycogen concentration and food intake was studied on 104 male adult Wistar rats. When saline was injected the amount of food ingested was similar to that expected at the metabolic moment selected for the tests. Glucose administration did not reduce food intake but both insulin and glucagon provoked a threefold increase during the 60 minutes ensuing the injection. The overall ingestion of food during the 24 hours after the injection of the hormones was significantly higher (about 10%) than the control values during the preceding or the succeeding 24 hours. A hyperphagic, rather than a hypophagic effect of glucagon administration is possibly related to the small dose used in the experiments. The mechanisms involved in the increase of food intake due to glucagon are discussed in terms of acceleration of the metabolic reactions that normally prevent large drops of glycemia as glucose utilization proceeds during the inter-meal periods and that in physiological conditions build up until the need for food arises.     

Puberty and olfactory preferences of males

The preferences of 302 males, aged 8–9, 14 and 16 years, for ten food related odors were determined using a hedonic scale. The aim was to establish if major changes in preferences occur during the period which encompasses puberty. Small but significant differences between the 8–9 year group and the others were obtained for meat and chicken odors; between the 14 year group and the others for peanut butter odor; and there was a change from dislike to like with age for coffee odor. The results were almost all confirmed in a retest. The general lack of differences between the responses of the three age groups indicated that no major change occurs in preferences for food odors between the ages of 8 and 16 years. Although these results indicate that olfactory preferences for food odors are not affected by puberty, they do not eliminate the possibility that preferences may be altered for odors related to sex and emotion [13].     

Stimulus range influences intensity and hedonic ratings of flavour

Five concentrations of an artificial orange drink were presented for sensory evaluation in three overlapping concentration ranges. Three sensory panels, each of 30 subjects, rated the concentrations for intensity of flavour (intensity scale), relation to ideal flavour intensity (ideal-point scale), and pleasantness (hedonic scale). Except for the two extreme concentrations, neither of which was presented in more than one range, in all three response tasks the mean rating for a given concentration varied with the concentration range in which it was presented. However, the mean ratings showed good correspondence across response tasks (e.g. the concentration perceived as "moderately sweet" on the intensity scale was perceived as "just right" on the ideal-point scale and of maximal pleasantness on the hedonic scale), suggesting a link between the intensity and hedonic dimensions of sensory experience.     

Dietary fat intake and taste responses to fat in milk by under-, normal, and overweight women

Dietary fat intake, with special emphasis on dairy products, was estimated from questionnaires for 42 underweight, 80 normal weight, and 64 overweight adult women. Frequency of consumption of fresh and processed meats, frozen dairy desserts, pastries, and snacks such as potato chips was greater for the overweight than for the underweight subjects. However, preferences between verbally-described high- and low-fat versions of 14 food pairs did not differ by body size. Overweight subjects reported that they consumed more non-fat milk and less whole milk than did the other groups. Discrimination, perceived intensity, paired preference, and hedonic rating of fat in milk and in chocolate milk did not differ significantly according to body size, fat intake, or type of milk consumed. Ad libitum mixing of non-fat milk and "half and half" (12% fat) to individual levels of liking also showed no significant variation with body size. However, subjects with higher dietary fat intakes mixed to higher fat-preference levels in milk than did the low- and medium-fat intake subjects. Those reporting consumption of regular milk (3.5% fat) mixed to higher fat levels than did those who consumed low-fat (2% fat) or non-fat milk. The ad libitum procedure gave better reproducibility and appeared to be a more realistic measure of liking than the hedonic rating or paired-preference tests.     

Body weight set point studies in weanling rats with dorsomedial hypothalamic lesions (DMNL rats)

In order to further characterize a previously postulated "organismic" set point, weanling DMNL and control (CON) rats were maintained on lab chow ad lib (AL) for 55 post-operative days. Subsequently, some DMNL and CON rats were food-restricted (REST) to 80% of the food intake of their AL-fed counterparts for 24 days. At this point, representative rats from each group were killed by decapitation and the remaining animals were re-fed AL and killed 7 and 22 days thereafter. At the end of REST, both DMNL and CON showed significant weight loss, which was greater in CON than in DMNL rats. After 7 days of refeeding, DMNL rats normalized their body weights but re-fed CON still weighed less than AL-fed CON 22 days after refeeding. Food intake in formerly REST groups overshot on refeeding for 7 days, but this was significant only in DMNL rats. Notably, during this time formerly REST-DMNL ate as much as AL-fed CON. Efficiency of food utilization was normal in DMNL during AL feeding and became reduced on REST as it did in REST-CON. Notably, on refeeding formerly REST-DMNL rats overshot that of AL-fed DMNL rats by the same magnitude as previously REST-CON overshot the values of AL-fed CON. After 22 days of refeeding, this overshoot was still evident in DMNL but not in CON. At the end of the REST period, plasma insulin and glucose were similar in AL-fed DMNL and AL-fed CON. They were significantly and comparably reduced in both REST-DMNL and REST-CON compared to the AL-fed DMNL and AL-fed CON. On refeeding these changes normalized within seven days. At the end of REST, plasma free fatty acid concentrations were higher in REST-DMNL and REST-CON than in AL-fed DMNL and AL-fed CON. After seven days of refeeding they normalized only in formerly REST-CON. Plasma glycerol and total protein were normal throughout all groups, as was carcass protein. Carcass fat was equivalently reduced in both DMNL and CON at the end of REST and normalized 7 days after refeeding. AL-DMNL had the same carcass fat as AL-CON and REST-DMNL had the same carcass fat as REST-CON. In conjunction with previously reported normal anabolic hormone levels the data suggest that DMNL rats are not growth-retarded but are merely scaled down in size without compromise of their homeostatic competence. We take this as strong evidence for the existence of an "organismic" set point.     

2010—2019年江西省居民食物消费量变化趋势研究

目的 分析2010—2019年间江西省居民食物消费变化趋势。方法 采用多阶段分层的整群抽样的方法,2010—2012年和2018—2019年分别抽取调查对象1 967人和1 130人。采用非连续的3天24小时回顾询问法、称重法收集和食物频率法对居民开展膳食调查,利用t检验对2010—2012年和2018—2019年居民各类食物摄入量进行统计分析。结果 2010—2019年间江西省城乡居民谷薯类食物消费量总体呈下降趋势（t = - 14.816,P＜0.001）,平均每标准人日摄入量由469.2 g降至398.3 g,但城市却呈上升趋势。蔬菜（t = - 22.258,P＜0.001）和水果（t = - 11.105,P＜0.001）消费量总体呈下降趋势,平均每标准人日摄入量分别由316.5 g和66.9 g降至240.5 g和48.0 g,但城市居民水果消费量呈上升趋势。禽畜肉类（t = 6.591,P＜0.001）、水产品（t = 12.531,P＜0.001）、蛋类（t = 13.944,P＜0.001）、奶类（t = 5.071,P＜0.001）和大豆及坚果类（t = 17.880,P＜0.001）呈上升趋势,平均每标准人日摄入量分别由97.6 g、24.0 g、18.1 g、19.5 g和16.6 g增至111.7 g、43.0 g、27.9 g、26.3 g和40.4 g,其中城市禽畜肉和奶类增幅都明显高于农村。油脂类（t = - 18.444,P＜0.001）和食盐（t = - 40.029,P＜0.001）消费量都呈下降趋势,平均每标准人日摄入量分别由43.8 g和9.1 g降至31.1 g和7.8 g,其中城市油脂类降幅高于农村。结论 江西省居民食物消费状况总体有所改善,但仍存在不合理,蔬菜水果、奶类摄入不足,而禽畜肉、油脂类和食盐过高,导致膳食纤维和钙的摄入不足,而脂肪摄入过多。     

Using aggregated mobile phone location data to compare the realised foodscapes of different socio-economic groups.

The foodscape (the built food environment) is considered one of the driving factors of the higher burden of obesity and chronic disease observed in low socio-economic status (SES) groups. Traditional data collection methods struggle to accurately capture actual access and exposure to the foodscape (realised foodscape). We assess the use of anonymised mobile phone location data (location data) in foodscape studies by applying them to a case study in Perth, Western Australia to test the hypothesis that lower SES groups have poorer realised foodscapes than high SES groups. Kernel density estimation was used to calculate realised foodscapes of different SES groups and home foodscape typologies, which were compared to home foodscapes of the different groups. The location data enabled us to measure realised foodscapes of multiple groups over an extended period and at the city scale. Low SES groups had poor availability of food outlets, including unhealthy outlets, in their home and realised foodscapes and may be more susceptible to a poor home foodscape because of low mobility.