Seasonal Variation In Body Weight Research Articles

Seasonal and subtype differences in body mass index at admission in inpatients with anorexia nervosa.

In the general population, body weight is-on average-higher in the winter than in the summer. In patients with anorexia nervosa (AN), however, the opposite pattern has been reported. Yet, only a handful of studies exist to date that suffer from small sample sizes and inconsistent results. Therefore, the current study examined seasonal effects on body weight in a large sample of patients with AN to dissolve previous inconsistencies. Clinical records of N = 606 inpatients (95.4% female) who received AN treatment at the Schoen Clinic Roseneck (Prien am Chiemsee, Germany) between 2014 and 2019 were analyzed. Patients with restrictive type AN had lower body mass index at admission in the winter than in the summer. This difference was not found for patients with binge/purge type AN and patients with atypical AN. Individuals with restrictive type AN show seasonal variations in body weight that are opposite to seasonal variations in body weight in individuals without AN. These seasonal effects are specific to the restrictive subtype and cannot be found for the binge/purge or atypical subtypes. Future studies that replicate this effect in other cultures or latitudes and that examine the mediating mechanisms are needed.

Distinguishing disease effects from environmental effects in a mountain ungulate: seasonal variation in body weight, hematology, and serum chemistry among Iberian ibex (Capra pyrenaica) affected by sarcoptic mange.

Our study focuses on the Iberian ibex (Capra pyrenaica) from the Sierra Nevada Natural Space (southern Spain), where sarcoptic mange is an endemic disease and animals are affected by a highly seasonal environment. Our aim was to distinguish between disease and environmental influences on seasonal variation in body weight, hematology, and serum biochemistry in Iberian ibex. We sampled 136 chemically immobilized male ibexes. The single effect of mange influenced hemoglobin, hematocrit, mean corpuscular volume, leukocytes, band neutrophils, monocytes, cholesterol, urea, creatine, and aspartate aminotransferase. Both mange and the period of the year also affected values of mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, neutrophils, glucose, and serum proteins. Scabietic animals showed a marked reduction in body weight (21.4 kg on average), which was more pronounced in winter. These results reveal that 1) infested animals are anemic, 2) secondary infections likely occur, and 3) sarcoptic mange is catabolic.

Circannual changes in stress and feeding hormones and their effect on food-seeking behaviors

Seasonal fluctuations in food availability show a tight association with seasonal variations in body weight and food intake. Seasonal variations in food intake, energy storage, and expenditure appear to be a widespread phenomenon suggesting they may have evolved in anticipation for changing environmental demands. These cycles appear to be driven by changes in external daylength acting on neuroendocrine pathways. A number of neuroendocrine pathways, two of which are the endocrine mechanisms underlying feeding and stress, appear to show seasonal changes in both their circulating levels and reactivity. As such, variation in the level or reactivity to these hormones may be crucial factors in the control of seasonal variations in food-seeking behaviors. The present review examines the relationship between feeding behavior and seasonal changes in circulating hormones. We hypothesize that seasonal changes in circulating levels of glucocorticoids and the feeding-related hormones ghrelin and leptin contribute to seasonal fluctuations in feeding-related behaviors. This review will focus on the seasonal circulating levels of these hormones as well as sensitivity to these hormones in the modulation of food-seeking behaviors.

A prospective longitudinal study of seasonality in African students living in the greater Washington, D.C. metropolitan area.

We conducted a prospective, longitudinal study of seasonality in a vulnerable population, i.e., African students who migrated to a temperate climate. Consistent with previous cross-sectional studies, we hypothesized lower mood and energy, and higher appetite and weight, in fall/winter than in spring/summer. Four cohorts of African students attending a year-long nursing school program without vacation in Washington, D.C., were assessed monthly for 1 year. Forty-three subjects (mean age = 33.46 ± 6.25), consisting of predominantly females (76.7%), completed the study. The cohorts began their academic program in different seasons (one each in winter, spring, summer, and fall), inherently minimizing confounding influences on seasonality, such as academic and immigration stress, as well as allowing adjustment for an order effect. At each assessment, students completed three 100-mm visual analog scales for mood, energy, and appetite, and were weighed on a digital scale. For each standardized dependent variable, a repeated measure ANOVA was used and, if a significant effect of month was identified, averages for spring/summer and fall/winter were compared using paired ttests. In addition, a mixed model for repeated measures was applied to raw (nonstandardized) data. Body weight was significantly higher in fall/winter than in spring/summer (p < 0.01). No seasonal differences in mood, energy, or appetite were found. Benefiting from certain unique features of our cohorts allowing adjustment for order effects, this is the first study to identify a seasonal variation in body weight with a peak in winter using longitudinal monthly measurements.

Sex, age and season influence morphometries in the New Zealand Stitchbird (or Hihi; Notiomystis cincta)

While it is generally considered that males and females have different body measurements, other factors may be important in affecting the uniformity of morphometric parameters within populations. In this 4-year longitudinal study I examined the influence of sex, age and time of year on five body measurements in the Stitchbird (or Hihi (Notiomystis cincta)): (1) tarsal length, (2) total head-length, (3) wing-length, (4) length of ear-tuft, and (5) weight. As with previous analyses of Stitchbird morphometrics, males were significantly larger and heavier than females. However, the age of birds and the time of year significantly affected several body measures. Tarsus was the most stable measure, remaining unchanged after 21 days of age. Wings were the least stable, being significantly affected by sex (females smaller than males), age (1-year-olds smaller than 2-year-olds, which were smaller than 3-year-olds) and season (with wing-length pre-moult smaller than wing-length post-moult). Differences between age-classes within the population reflected changes in individuals over time, with individuals having progressively longer wings and ear-tufts as they aged. Male and female Stitchbirds showed significant seasonal variation in body-weight, with weight reaching a maximum in winter and a minimum during the spring-summer breeding season. While the starvation-predation hypothesis commonly explains seasonal fluctuations in weight of birds, Stitchbirds lose weight during the coldest part of the year, immediately before the breeding season. This change in weight potentially maximises their agility when competing for mates in a mating system characterised by intense sperm competition.

Seasonal Body Weight Variation in Five Species of Woodpeckers

AbstractWe investigated patterns of seasonal variation in body weight in six populations of five resident species of temperate-zone woodpeckers: Acorn Woodpecker (Melanerpes formicivorus), Red-bellied Woodpecker (M. carolinus), Red-cockaded Woodpecker (Picoides borealis), Downy Woodpecker (P. pubescens), and Great Spotted Woodpecker (Dendrocopos major). After controlling for time of day and overall body size, annual variation in body weight was small and generally not statistically significant. However, analysis revealed evidence of significant “winter fattening,” comparable in magnitude to other temperate-zone resident species, in three of the species. The degree of winter fattening did not correlate with either the size of the acorn crop (for the Acorn Woodpecker) or latitude, two variables potentially related to predictability of food resources. However, the smaller species exhibited significantly greater winter fattening than the larger species, as predicted by the hypothesis that energy storage should be more important for small-bodied species. Furthermore, the food-storing Acorn Woodpecker exhibited considerably less winter fattening than the nonfood-storing species, supporting the hypothesis that food storage provides an ecological alternative to winter fattening.

The relationship between obesity and seasonal variation in body weight among elementary school children in Tokyo

Typical patterns of seasonal variation in body weight among Japanese children involve increases during the fall and/or winter and decreases during the summer. However, atypical variations, namely, increases in weight during the summer, have been reported for obese children. The present study examines whether weight gain during the summer (i.e., July through September) is a possible cause of obesity. We examined seasonal changes in weight for 446 elementary school children in Tokyo in six waves between 1972 and 2004. Weight was measured monthly for 6 years in each child and was evaluated by means of time-series analysis. Overall, significant seasonal variations in weight were found in 86% of the children, most of which were typical (i.e., decreases during the summer and increases during the fall, winter, and/or early spring). On the other hand, weight gain in the summer was observed exclusively among obese children. Children whose weight increased during the summer holiday spent most of their time comfortably indoors because of air conditioners, which became popular in 1970s. A possible explanation of the observed weight gain during the summer seems to be changes in life style associated with the use of air conditioning, concomitant with insufficient physical exercise and excessive consumption of food and drink, which could disturb the rhythms of seasonal weight changes and lead to obesity.

Regulation of body weight and thermogenesis in seasonally acclimatized Brandt's voles ( Microtus brandti)

Seasonal changes in an animal's morphology, physiology, and behavior are considered to be an adaptive strategy for survival and reproductive success. In the present study, we examined body weight and several behavioral, physiological, hormonal, and biochemical markers in seasonally acclimatized Brandt's voles ( Microtus brandti) to test our hypothesis that Brandt's voles can decrease energy intake associated with decrease in body weight, body fat content, serum leptin level, and increasing thermogenesis in winter conditions. We found that the body weight of Brandt's voles was lowest in winter (December to February) and highest in spring and early summer (May to June). This seasonal variation in body weight was associated with changes in other markers examined. For example, the winter decrease in body weight was accompanied by increased energy intake and enhanced nonshivering thermogenesis (NST) as well as by decreased body fat mass and reduced levels of circulating leptin. Further, circulating levels of leptin were positively correlated with body weight and body fat mass, and negatively correlated with energy intake and uncoupling protein 1 contents. Together, these data do not support our hypothesis and suggest that leptin may be involved in this process and serve as a starvation signal in Brandt's voles.

SEASONAL BODY WEIGHT VARIATION IN FIVE SPECIES OF WOODPECKERS

We investigated patterns of seasonal variation in body weight in six populations of five resident species of temperate-zone woodpeckers: Acorn Woodpecker ( formicivorus), Red-bellied Woodpecker (M. carolinus), Red-cockaded Woodpecker (Picoi- des borealis), Downy Woodpecker (P. pubescens), and Great Spotted Woodpecker (Den- drocopos major). After controlling for time of day and overall body size, annual variation in body weight was small and generally not statistically significant. However, analysis re- vealed evidence of significant ''winter fattening,'' comparable in magnitude to other tem- perate-zone resident species, in three of the species. The degree of winter fattening did not correlate with either the size of the acorn crop (for the Acorn Woodpecker) or latitude, two variables potentially related to predictability of food resources. However, the smaller species exhibited significantly greater winter fattening than the larger species, as predicted by the hypothesis that energy storage should be more important for small-bodied species. Further- more, the food-storing Acorn Woodpecker exhibited considerably less winter fattening than the nonfood-storing species, supporting the hypothesis that food storage provides an eco- logical alternative to winter fattening.

Seasonal variation in body weight: an experimental case study

The effect of seasonal variation in ambient temperature on body weight was studied in a man. Data were collected over three consecutive years in a temperate climate, including a two-week shift in winter to a tropical environment. A strong negative correlation existed between body weight and ambient temperature ( r 2=0.58, p<0.0001), except for the season with shift to the tropics. In the latter case, body weight dropped from 60.0 to 57.6 kg and remained low until summer, despite ambient temperatures down to –4.7°C in late winter. In conclusion, body weight shows a clear seasonal variation triggered by ambient temperature.

Seasonal variations in blood parameters of the Amazonian manatee, Trichechus inunguis

Seasonal variations in body weight, food consumption and blood glucose, total lipids, urea, total proteins, albumin and globulins of captive Amazonian manatees, Trichechus inunguis, were determined. Body weight changed significantly along the year, increasing from autumn to spring and decreasing in summer. The mean daily food intake of paragrass remained almost unchanged along the year. Paragrass administered to the manatees showed important variations in crude protein and lipid content along the year. No significant differences in blood parameters were registered between males and females in all seasons. Further, there were no significant differences in blood total proteins, albumin and globulins along the year. On the other hand, significant differences in the mean blood glucose, lipids and urea were registered. An increase in the blood glucose in the spring and summer was observed. Blood urea and lipids levels were positively related to paragrass protein and lipids content. These two correlations suggested that these blood parameters are good indicators of the animal nutritional status in the Amazonian manatee.

Aspects of social life in the fat-tailed dwarf lemur (Cheirogaleus medius): inferences from body weights and trapping data.

Body weight is an important attribute of any animal and influences its biology in many ways. In the case of the fat-tailed dwarf lemur (Cheirogaleus medius), this is of special interest because animals of this species store fat to survive extended torpor phases during the austral winter and, as a result, show extreme seasonal variation in body weight. In this paper, I present field data from a 20-month study at the Forestry Station of Ampijoroa in northwestern Madagascar on body weights of repeatedly trapped individuals combined with trapping results to investigate the general biology and notably the social life of C. medius. The most remarkable physical characteristic of wild C. medius is a dramatic weight-loss in males in September following emergence from torpor. Trapping results showed that adult males emerge from torpor earlier than females and offspring, even though food is still scarce. Early emergence from torpor puts males at an energetic disadvantage and confers no advantage in terms of access to females. Observation data from nightly follows indicate that males patrol their home range, probably to guarantee its integrity for the coming active season and to secure the food supply for their families. The high energetic costs of this strategy is argued to represent a form of paternal investment. Body weight data of repeatedly captured individuals showed that they may reach adult size and sexual maturity at 2 years of age but are not socially mature before the age of 3 years. The data presented may serve as a guide for keeping C. medius at a suitable weight in captivity.

Ecology and Behavior of the Pouched Mouse, Saccostomus mearnsi, in Central Kenya

I investigated the ecology and behavior of Saccostomus mearnsi, a medium-sized semi­ fossorial murid rodent for 15 months in a tropical savanna of central Kenya. This poorly known species is the dominant small mammal in this widespread habitat, although it has never before been reported in high local abundance. On three replicated I-ha grids, S. mearnsi exhibited a 2.5-fold change in abundance over 15 months from 16 ± 3.5 (SE) to 42 ± 7.5 individualslha. S. mearnsi had strongly seasonal reproduction, with almost all females in breeding condition following the rainy season, while only 10% were in breeding condition during the dry season. Eighty-five percent of males, however, remained in breed­ ing condition throughout the year. Adults of both sexes exhibited great variation in body weight (males, 48-121 g; females, 39-94 g). There was significant seasonal variation in body weight for both sexes. Home ranges of males (0.21 ± 0.02 ha) were three times the size of those of females (0.06 ± 0.01 ha); and the average of the maximum distances moved by males between captures varied significantly between seasons. Analyses of stom­ ach contents showed that S. mearnsi was omnivorous, consuming primarily forbs during the dry season and seeds following the rains. Adults share burrow entrances in termite mounds; whether or not they nest individually or communally remains to be determined.

Seasonal Variation in Blood Pressure in Normotensive Women Studied by Home Measurements

1. The factors influencing the seasonal variation in blood pressure measured at home in normotensive women were examined. 2. Sixteen female subjects (56.3 +/- 7.9 years old, mean +/- SD) measured their blood pressure and pulse rate at home each morning for more than 20 times per month for at least 1.5 years. Blood pressure and body weight were also determined in the office once or twice a month in that period. Monthly means of outdoor and indoor temperatures and daytime length were obtained from the Meteorological Observatory. The single cosinor method was used to evaluate circannual rhythm. 3. We observed a biphasic seasonal variation in self-recorded blood pressure measured at home, environmental temperature and daytime length but found no apparent seasonal variation in body weight and blood pressure measured in the office. The lowest levels of systolic and diastolic blood pressure measured at home were observed in July. The longest daytime length was recorded in June, while the highest outdoor temperature and indoor temperature were recorded in August, indicating that the longest daytime length preceded and the highest environmental temperature lagged behind the lowest level of blood pressure. The shortest daytime length is in December. The lowest outdoor and indoor temperature were observed in January, while the highest levels of self-recorded systolic blood pressure and diastolic blood pressure were in January and December, respectively. Half-amplitudes of self-recorded systolic and diastolic blood pressure were 2.6 +/- 1.0 mmHg and 2.0 +/- 0.8 mmHg, respectively. 4. These findings indicate the importance of a seasonal effect, i.e. daytime length and the environmental temperature, on the blood pressure of individuals.

小学生の肥満は夏休みに始まる

Normal Japanese children are considered to have seasonal variation in body weight which increases in fall and winter and decreases in summer. However, abnormal seasonality was found in some of elementary school children in Tokyo, that is, body weight increased in summer in children. In most elementary schools in Tokyo, summer holidays begin in the latter part of July and end on August 31 . So, children might spend quite different life during the holidays compared with school days. The present study examined seasonality in body weight of 91 elementary school children living in Nagasaki City where the period of summer holidays is the same as in Tokyo. Then, the relationship between obesity and weight gain in summer holidays was discussed. Body weight has been measured monthly for six years (excluding August). Time-series analysis was made by the Program of Census Method II X-11 in which the original series O is assumed to be the product of three components as follows; O =C × S × I, where C is trend-and-cycle factor, S is seasonal factor, and I is irregular factor. Significant seasonal variations were observed in about 90% of the children. The pattern of seasonal variation of group means was low in summer and high from fall to winter or early spring in both sexes. Rohrer's index in 17 children were over 145 at least once through six years and they were classified as obese group. Among the group 11 children had high seasonal factors from July to September, which indicates that body weight increased in summer holidays. In other children whose seasonal factors did not have peaks in September, Rohrer's index gradually lowered. Thus we conclude that weight gain in summer holidays is the most critical warning of obesity in school children.

Photoperiod and the regulation of annual and circannual cycles of food intake

For wild animals, food availability usually exhibits considerable seasonal fluctuations and as a result dramatic seasonal variations in body weight, fatness and food intake are often observed. Birds and mammals living in the temperate zones or higher latitudes, therefore, time the onset of reproductive activity each year with great precision

Mycobacterium bovis in the European badger (Meles meles): epidemiological findings in tuberculous badgers from a naturally infected population.

This study investigates the course of tuberculosis in a naturally infected badger population, its impact on the population and the risk of spread to other species in the light of capture data and post-mortem findings from 47 tuberculous badgers, stratified by age group and sex, accrued since 1975. The findings are compared with those for 260 badgers from the same population in whom no evidence of infection was detected. Detailed estimates of seasonal variations in bodyweight for uninfected male and female cub, yearling and adult badgers are presented and compared to the weights at post-mortem examination of the tuberculous badgers, in whom poor condition and weight loss were the principal presenting signs. Lesions were seen especially in the lungs and associated lymph nodes, and in the kidneys. Organisms were detected intermittently in faeces, urine, sputum and discharging bite wounds. Infected animals could survive for nearly 2 years and produce cubs successfully.

Is the annual cycle in body weight of pouched mice (Saccostomus campestris) the result of seasonal changes in audit size or population structure?

The annual cycle in body weight of pouched mice (Saccostomus campestris) was examined among 104 specimens which were collected throughout the year in the Transvaal province of South Africa. Each specimen was assigned to one of five age classes using toothwear characteristics although none of them belonged to the youngest age class. There was no significant effect of sex on body weight but older individuals were significantly heavier than younger ones. Pooled data from both sexes displayed seasonal variation in body weight with significantly heavier animals in the wet season (December‐March) than during the dry season (June‐September). However, there was no significant difference between the age structure of the population at these times. Instead, pouched mice in the two younger age classes were significantly lighter in the dry season compared to the wet season, while older individuals maintained a relatively constant body weight throughout the year. These results suggest that the annual cycle in body weight of S. campestris is caused by a reduction in body weight of young animals which lose weight in winter as an adaptation to limit their energy requirements when food availability declines.

Seasonal variation in body weight of the bivalves Macoma balthica, Scrobicularia plana, Mya arenaria and Cerastoderman edule in the Dutch Wadden sea

The paper deals with the seasonal and annual variations in the weight of the soft parts of four bivalve species, Macoma balthica, Scrobicularia plana, Mya arenaria and Cerastoderma edule from tidal flats of the Dutch Wadden Sea. The paper reviews methodology and points to error sources. The variation in ash-free dry weight between individuals of the same size collected at the same time and place could be attributed to age, parasitic infestation, gametogenesis, burying depth and siphon size. The allometric relations between weight of soft parts and size are given in equations, averaged per month. The body weight of all four bivalve species peaked in May and June at a level approximately twice the lowest value, which occurred in November to March. The extent of this seasonal fluctuation varied, however, from year to year. The presence of gametes explained a part of the peak weight in summer. Winter losses of body weight were less at low temperatures, due to reduced energy expenditure when the animals are inactive. No large differences were found between the seasonal changes in body weight in the Wadden Sea and elsewhere in the temperate zone.

The Biology of the Common Sheath-Tail Bat, Taphozous-Georgianus (Chiroptera, Emballonuridae), in Central Queensland

A field study was carried out over a 4-year period on the common sheath-tail bat, Taphozous georgianus, in central Queensland. Mating occurred in late August and early September, and females gave birth to a single young in late November or early December. Females mated at about 9 months of age. Spermatogenesis commenced in males at about 9 months but they were not able to take part in mating until they were approximately 21 months old. Bats were born well furred with their eyes open, and weighed an average of 24% of their mother's post-partum weight. Young bats attained independence at 3-4 weeks old when they reached 50% of their mothers' body weight. At 3 months old young bats were within a few millimetres of adult dimensions. Marked seasonal variations in body weight resulted from the deposition of fat. Peak weights were recorded in April and minimum weights in September. The mean annual survivial rate was estimated to be 0.61. Mature males have a mortality rate substantially greater than females and this is reflected in a sex ratio strongly biased towards females in older bats. The sex ratio was nearly even in young bats. Most roost caves were occupied by less than 20 individuals. There was little difference between the temperature and humidity at which bats roosted, and the temperature and humidity of available roosts. Most bats were known from only one cave, and few movements of more than 2 km were recorded. Bats appeared to regularly relocate their roosting site, however, and they may have been utilising roosts outside the study area.