Daily Weight Loss Research Articles

Metabolism and survival of fasting Estuarine crocodiles

Carbon dioxide production by fasting immature Estuarine crocodiles was between 0·023 and 0·042 mlg‐1h‐1. The calculated oxygen consumption was between 46% and 70% of that expected from the crocodiles weights. The daily percentage weight loss while fasting is given by 0·020 + 0·584 (days without food)‐1. Survival time of crocodiles that failed to feed after hatching was related to initial weight, death occurring after 27·4% of the initial weight had been lost. Fat was the principal nutrient catabolized by fasting crocodiles. The results are consistent with those expected of an inactive predator that rapidly lowers metabolic rate to starvation levels when food is unavailable and can thus withstand extended fasts.

Changes in body mass, body temperature and plasma fuel levels during the natural breeding fast in male and female emperor penguinsAptenodytes forsteri

1. Changes in body temperature (Tb), body mass, plasma glucose, free fatty acid (FFA) and β-hydroxybutyrate levels were investigated in free-living male and female emperor penguins throughout the 115-and 45-day, respectively, natural breeding fast on the sea-ice. Moreover, changes during a prolongation of this fast that mimicked the supplementary energy expense for walking back to the open sea, were also studied in captive emperors. 2. A decrease of the daily weight loss (DWL),Tb and plasma fuel levels during the days following the arrival in the breeding area (Table 1) probably reflected recovery from the streneous exercise emperors had to perform walking towards the colony. 3. Plasma FFA levels were slightly and markedly increased during oesophageal ‘curd’ secretion in males, and egg-yolk formation in females, respectively. Marked hyperthermia and hyperglycemia was observed during egg laying in females. 4. Long-term natural fasting was characterized by homeothermia (37.1°C), maintenance of high plasma glucose (12.8 mmol/l) and moderate plasma FFA (0.7 mmol/l) levels, and progressive modest ketosis (1.5 mmol/l) (Figs. 1 and 2), which probably reflect continuous availability and preferential utilization of fat stores. 5. During prolongation of the fast, marked increases in DWL and decreases in plasma FFA and β-hydroxybutyrate were indicative of a metabolic shift from fat towards protein utilization after fat depletion. The decrease in plasma lipid fuels might serve to trigger the spontaneous interruption of the natural fast.

RENAL FUNCTION IN INFANTS < 1250 G (VLBW) IN THE FIRST THREE DAYS OF LIFE

Renal function has been measured extensively in larger and older preterm infants. We studied 16 VLBW infants during the first three days of life. Eight infants were studied with 50 mg/kg boluses of inulin followed by infusions of 0.1 mg/kg/min. The other eight received 100 mg/kg and 0.2 mg/kg/min, respectively. The mean inulin levels were 19.5± 5.96 mg/dl (mean ± SD) and 65.0 ± 59.8 mg/dl, respectively. Timed urines were collected for 4 to 7 hrs and inulin clearances (IN) calculated in standard fashion. An attempt was made to allow a daily weight loss of 1.5-3.5% of birthweight. The gestational age was 28.5 ± 2.2 weeks and the birthweight, 990 ± 158 G. The results are not different between protocols and are combined. The daily change in values was not significant. IN did not correlate with either urine flow nor IV rates. Individual IN values ranged from .039 to 1.54 ml/kg/min. 9 of 16 infants had average IN > .3 ml/kg/min. IN and FeNa in VLBW infants < 72 hours old are lower than in older infants. *Fractional sodium excretion. One study coincident with furosemide treatment was omitted.

Daily measurements of variation in weight loss of eggs of seven passerine species before and during natural incubation

The eggs of one or more clutches of seven passerine species were weighed each day from the day they were laid until hatching. In all seven, the rate of weight loss increased during incubation. This increase was more rapid in the early stages, leading to curvilinear regression. Linear regression was, however, highly significant and explained over 80% of the variation in four species. Curvilinear regression was significant in two other species. The weight loss curve of a single unfertilized Barn Swallow, Hirundo rustica, egg was similar to that of the rest of the clutch until they commenced to pip. The daily weight loss of five unincubated eggs also increased with time. Shell damage was suspected to be the cause of sudden increases in weight loss of individual eggs. A simultaneous drop in weight loss by six clutches was probably caused by high humidity. Other decreases in weight loss may have been caused by rain. Mean weight loss from water vapour conductance through the shell as a percentage of initial egg weight was 0.9 ± 0.08 during the laying period, 12.0 ± 0.72 during the laying period plus the incubation period prior to pipping, and an estimated 14.6 ± 0.85 for the laying period and the whole incubation period.

Daily body energy balance in rats

The aim of the present study was to examine the balance between caloric intake and expenditures in successive 12 and 24 hour periods, for several consecutive days in rats. The simultaneous and continuous measurements of respiratory exchanges and of the spontaneous feeding pattern were performed in 6 rats during 38 days, in periods of 2 to 4 successive days. At night, caloric intake exceeded caloric expenditures by 32% on the average. In individual rats, the excess was positively correlated to meal size but not to meal number. During the daytime, caloric intake was 24% lower on the average than the concomitant energy expenditures. In individual subjects, these deficits were correlated to meal number but not to meal size. A nocturnal excess and the subsequent daytime deficit, and the diurnal deficit and the excess during the subsequent night were highly positively correlated. In fact, the 24 hour energy balance was either slightly positive (12% excess) or negative (4% deficit). The daily weight gain or loss was highly correlated to the residual excess and/or deficit with a mean caloric cost of 4.8 kcal per g of body weight. The absence of correlation between balances on successive days indicates that the body energy balance is regulated within 24 hr through 12 12 hr compensations and that no compensatory mechanisms are involved beyond 24 hr.

Produção de leite em pastagens de gramíneas, com e sem nitrogênio, em manejo contínuo

Twelve lactating crossbred cows, similar in size and production, were distributed in a completely randomized design, being treated with Brachiaria decumbens and Panicum maximum grasses, mixed at a rate 66% — 34% respectively, diferenciated by: treatment A) nitrogen fertilized -100 kg N/ha; treatment B) without fertilization. The grasses were continuously grazed, and all treatments had 3,3 cows/ha. Fat connected milk productions by cow day and daily weight losses were respectivelly: A) 9,9 kg and -0,355 kg/day and B) 9,0 kg and -0,326 kg/day. There were none statistical differences between treatments, during the experimental period of 70 days.

Sucrose polyester and covert caloric dilution

Total daily caloric intake was measured in 10 obese subjects when sucrose polyester (SPE), a nonabsorbable synthetic fat, covertly replaced conventional fats in a single crossover study consisting of three periods: a period of 7 to 14 days to determine baseline caloric intake and two 20-day study periods. An average of 60 g SPE/day replaced conventional fat in one of the two study periods. During both study periods, 60% of the base line caloric intake was "required intake" at mealtime; an additional 60% of base line caloric intake was allowed as "free choice" foods at a specified snacktime. It was thus possible during both study periods to consume more than 100% of the base line caloric intake. In the SPE study period, 40 g SPE replaced 40 g conventional fat for every 1200 kcal of required intake, resulting in a 30% reduction in mealtime caloric intake. Mean total caloric intake (meal and snack) fell 23% during the SPE period (p less than 0.05), despite an average daily weight loss of 0.18 kg. Snack caloric intake did not increase significantly to compensate for caloric dilution of the meals during the SPE period. These results indicate that the obese may not detect or may not compensate for covert dilution of fat calories with SPE. In addition, during the SPE period, there was a 10% reduction in total plasma cholesterol, a 14% reduction in low-density lipoprotein cholesterol, and a 10% reduction in triglyceride concentration. Thus, fat replacement with SPE may benefit weight reduction regimens in obese subjects by facilitating decreased caloric intake and by improving the circulating lipoprotein profile as well.

Effectiveness of high-dose spironolactone therapy in patients with chronic liver disease and relatively refractory ascites.

Ten patients with ascites due to chronic liver disease were treated with spironolactone as the sole diuretic in doses of 300 to 600 mg daily. Prior to spironolactone treatment ascites was relatively refractory as indicated by baseline 24-hr urine sodium values of less than 5 mEq and natriuresis of less than 30 mEq following 200 mg hydrochlorothiazide. With spironolactone, mean daily weight loss was 540 g and natriuresis 74 mEq; diuresis was considered satisfactory in nine of ten patients. Untoward effects were limited to a single episode of hepatic encephalopathy, a small fall in serum magnesium in several patients, and three instances of hyperkalemia (5.5, 5.6, and 7.5 mEq/liter). In spite of the tendency to hyperkalemia, urinary potassium excretion increased in seven of the ten patients. There was no rise in serum urea nitrogen or creatinine. Hydrogen ion excretion decreased initially leading to mild hyperchloremic acidosis. Serum urate did not increase.

EFFECTS OF FEED LEVEL AND YEAR-ROUND ENCLOSED, SEMI-ENCLOSED, OR OUTSIDE CONFINEMENT ON BEEF COW–CALF PERFORMANCE IN NORTHERN ONTARIO

Shorthorn cows were confined year-round using three types of shelter (an enclosed barn, IN; a barn with free access to an outside yard, IN-OUT; and outside pens with only windbreak fences for shelter, OUT) and two types of feed (hay and grass silage) provided at three levels (ad libitum, L1 or 75%, L2 or 50%, L3, of ad libitum) until late pregnancy, after which all were fed their respective roughage ad libitum until late August weaning. No interactions were found among years, degree of shelter and feed levels. The average daily intake for hay and the corresponding average daily gain were greater (all differences cited were significant, P &lt; 0.05) than those for silage. The daily intake and weight loss of the OUT cows were greater than those of the IN and IN-OUT cows. All differences among feed levels for daily intake and weight change were significant. Calves of dams fed hay were heavier at birth and grew more quickly. OUT calves were heavier than IN calves at birth, but their daily gain to weaning was considerably less than either IN or IN-OUT calves. Feed levels did not influence calf birth weight, but L1 calves gained more to weaning than L2 and L3 calves. Pregnancy percentages for IN cows were 91.7 (L1), 91.7 (L2) and 75.0 (L3); IN-OUT 88.9, 88.9 and 86.1 and OUT 88.9, 80.6 and 58.3. The general condition of OUT cows, especially those on L3 diet, was poor.

Efficiency of α-Ketoisocaproic Acid as a Substitute for Leucine in the Diet of the Growing Rat

Immature male albino rats (70-80 g), eating a diet furnishing all nutrients for optimal growth and containing 84.6 mumoles of leucine/g, gained weight at an average rate of 5.9 g/day. Removal of leucine caused an average daily weight loss of 1.3 g. Addition of leucine to the diet in graduated amounts corrected this weight loss, the improvement in body weight (BW) being proportional to the dietary content of leucine. Addition of alpha-ketoisocaproic acid in place of leucine to the leucine-free diet also prevented loss of BW. Percentage efficiency of alpha-ketoisocaproic acid as a dietary substitute for leucine was calculated as: (see article). Efficiency of such substitution varied from 27% for a diet containing 84.6 mumoles of alpha-ketoisocaproic acid/g to 20% for a diet containing 169.2 alpha-ketoisocaproic acid/g.

Value of selective and truncal vagotomy in massive bowel resection

<h2>Abstract</h2> An investigation that compares selective vagotomy and pyloroplasty with truncal vagotomy and pyloroplasty in dogs with massive bowel resection is reported. The results suggest the following in animals with massive bowel resection:<ul><li>1. Selective and truncal vagotomy and pyloroplasty increase survival and decrease the per cent of daily weight loss when compared with values in the control group.</li><li>2. There is little or no difference in survival after selective vagotomy compared with that after truncal vagotomy.</li><li>3. Vagotomy and pyloroplasty increase absorption of nitrogen and fat and lengthen transit time when compared with values in control animals that also had massive bowel resection.</li><li>4. Vagotomy and pyloroplasty prolong survival and decrease weight loss but do not create an anabolic state and certainly do not represent the entire solution for the patient with massive bowel resection.</li><li>5. The adjunctive procedure is probably best delayed until after a period of observation with good medical management has been determined to be unsuccessful.</li></ul>

Value of selective and truncal vagotomy in massive bowel resection

An investigation that compares selective vagotomy and pyloroplasty with truncal vagotomy and pyloroplasty in dogs with massive bowel resection is reported. The results suggest the following in animals with massive bowel resection: 1. Selective and truncal vagotomy and pyloroplasty increase survival and decrease the per cent of daily weight loss when compared with values in the control group. 2. There is little or no difference in survival after selective vagotomy compared with that after truncal vagotomy. 3. Vagotomy and pyloroplasty increase absorption of nitrogen and fat and lengthen transit time when compared with values in control animals that also had massive bowel resection. 4. Vagotomy and pyloroplasty prolong survival and decrease weight loss but do not create an anabolic state and certainly do not represent the entire solution for the patient with massive bowel resection. 5. The adjunctive procedure is probably best delayed until after a period of observation with good medical management has been determined to be unsuccessful.

Energy provision, tissue utilization, and weight loss in prolonged starvation.

Daily weight loss measurements in 76 fasting, obese patients (58 females, 18 males) have shown a characteristic pattern of rapid loss initially (up to day 14) followed by a slower but uniform reduction in weight. There were significant sex differences. Measurements of tissue breakdown showed that the initial rapid weight loss was due to the continuing utilization by the nervous system of glucose derived from lean tissue. This requirement fell noticeably from the second week of starvation. Irreversible fluid elimination also contributed to the initial phase of rapid weight loss. Fat remained the primary source of energy throughout starvation and in established fasting (more than 14 days) contributed 96% of that requirement.

The Avian Egg: Incubation Time and Water Loss

large difference in incubation time among bird eggs, ranging from a minimum of 11 days to nearly 90, has aroused man's interest since antiquity. In her critical review of the history of our knowledge of incubation periods, Margaret M. Nice (1954) wrote, The people who have been concerned with incubation periods fall into three groups: the guessers, the copyists, the investigators. Guessers came first and these have been busily quoted since Aristotle for more than 20 centuries. It was not until Evans (1891) and Heinroth (1922) made their own observations that reliable data began to accumulate. In spite of the inaccuracies since Aristotle's time, and the many exceptions which are now well recognized, there is an obvious general correlation between egg weight and incubation period. These have been presented by Heinroth (1922), Needham (1931), and Worth (1940) in graphic form and were reinvestigated in this presentation on the basis of newer information in the literature. It is of interest to note in retrospect that all these correlations are essentially similar, that the standard error of estimates is large, and that there are many exceptions. This merely illustrates that the many factors which determine the incubation period are not understood. For these reasons we analyzed other correlates of egg size such as the gas conductance of the egg shell and particularly the water loss properties of eggs, problems which Heinroth had already mentioned some 50 years ago in his classical treatise on incubation time. On the basis of water vapor conductivity measurements of the egg shell previously presented (Ar et al. 1974), the daily weight losses of eggs during natural incubation reported by Drent (1970), and the reported incubation periods, one is now able to derive new relationships which apply to eggs in general. These indicate that incubation time for a given egg weight is inversely porportional to the water vapor conductance of the egg shell. Furthermore, during natural incubation all eggs, regardless of size, lose approximately 18% of their initial weight and the mean water vapor pressure difference between the egg and the microclimate of the nest is 35 torr.

Digestible and Metabolizable Energy Requirements for Winter Maintenance of Michigan White-Tailed Does

Eighteen pregnant white-tailed does (Odocoileus virginianus) were assigned to 6 trios on the basis of weight. They were penned individually out-of-doors from February S to April 9, 1969, and were fed a pelleted diet with a gross energy density of 4.20 keal/g and a crude protein percentage of 17.6. One member of each trio received the diet ad libitum; the second and third members received 75 and 50 percent of this amount, respectively. A subsequent l-week adjustment plus 1-week fecal and urine collection in metabolism cages was used to estimate the apparent digestible and metabolizable nutrient content of the diet. A linear regression of feed intake with average daily body weight gain or loss provided the basis for estimating maintenance energy requirements at mean weekly ambient temperatures ranging from 1.1 to -9.S C. The average estimated daily maintenance requirement for the 9-week period was 158 keal of apparently digestible energy and 131 keal of metabolizable energy per kg BW0 76. The following study was conducted to confirrn and extend our previous findings ( Ullrey et al. 1969 ) concerned with digestible energy needs for maintenance of body weight in captive adult white-tailed does during a Michigan winter. The development of an improved metabolism unit permitted the quantitative collection of both urine and feces and consequent calculation of metabolizable energy needs. The diet used was designed specifically for deer, and the formulation was based, in part, on deer research. We wish to acknowledge the assistance of Hazel Harte, Kay Cotton, Karen Jones, and Janice Mercer in performing laboratory analyses, and of E. H. Cunningham, F. L. Shippy, J. R. Terry, and R. E. Morrill for animal care. 1 Published with the approval of the Director of the Michigan Agricultural Experiment Station as Journal Article No. 5067. Supported by the Michigan Department of Natural Resources and PittmanRobertson Federal Aid in Wildlife Restoration Project Michigan W-95-R-ll. Research conducted at the Houghton Lake Wildlife Research Station. EXPERIMENTAL PROCEDURE Eighteen pregnant white-tailed does were assigned to 6 trios on the basis of weight so that the weights of the deer within a trio were as similar as possible. The heaviest individual deer within a trio was initially no more than 10 percent heavier than the lightest except for Trio 5 where there was a 19 percent difference. The mean body weights ( + SE ) for the deer in Trios 1 through 6, respectively, were 68.0 + 1.3, 64.0 + 1.7, 56.9 + 1.2, 57.3 + 1.2, 57.4 + 3.1, and49.7+1.3kg. All deer were 2.5 or 3.5 years old and had been raised in captivity from birth. They were penned individually out-ofdoors in an area 4.5 x 9 m. Protection from the weather was afforded by snow fence on two adjacent sides of the pen and a small roofed shelter. The other fences sere of

Diurnal Body Weight Loss and Tolerance of Weight Loss in Five Species of Myotis

Dawn to dusk weight loss of Myotis leibii and M. yumnnensis, caged singly, and M. lucifugas, M. thysanodes, and M. velifer, caged singly and in groups of four, was determined in their natural roosting environments. Individual weight losses ranged from 6.4 to 21.9 per cent of initial body weight, whereas weight loss of grouped bats ranged from 9.9 to 16.2 per cent. Roosting conditions, temperature and relative humidity, are reflected in daily weight loss. Grouped M. thysanodes lost significantly less weight than individually caged bats. There was no difference in weight loss of individual and grouped M. lucifugas and M. velifer. Weight loss at which half of the individuals of each species except M. leibii died ranged from 22.8 to 32.3 per cent of initial body weight.

Digestible Energy Requirements for Winter Maintenance of Michigan White-Tailed Does

Twenty-four pregnant white-tailed does (Odocoileus virginianus) were assigned to 8 trios on the basis of age and weight. They were penned individually out-of-doors from January 18 to April 12, 1967, and were fed a pelleted diet with a gross energy density of 3.48 kcal/g and a crude protein per- centage of 9.2. One member of each trio received the diet ad libitum; the second and third members received 75 and 50 percent of this amount, respectively, for a period of 9 weeks. For a subsequent 3 weeks, feed was provided ad libitum to all deer. A linear regression of feed intake with average daily body weight gain or loss provided the basis for estimating maintenance energy requirements at mean weekly ambient temperatures ranging from -1.0 to -13.0 C. Although the estimated maintenance re- quirement declined with time on experiment, the average estimate for the entire 9 weeks was 160 kcal of apparently digested energy per kg BW0'76 per day. During the recovery period of ad libitum feed intake, those deer which had previously lost weight most rapidly tended to gain weight most rapidly. Effects of level of food consumption on rumen fluid composition and certain blood components were also determined. It is common for Michigan deer to lose body weight during the winter. There are a number of reasons for this including a simple shortage of food as well as a short- age of preferred food species. There has been speculation that deer will not main- tain their body weight during this period of

Effects of Fasting and Refeeding. I. Studies on Sodium, Potassium and Water Excretion on a Constant Electrolyte and Fluid Intake

ABSTRACT Seventeen subjects were maintained on a constant electrolyte and fluid intake during periods of equilibration, starvation and refeeding. During 3 days of fasting, a mean daily weight loss of 800 g was accompanied by progressive natriuresis and kaliuresis without increase in urine volume. The net amount of sodium excreted as a consequence of fasting was independent of the amount of sodium supplemented. Carbohydrate refeeding induces very rapid antidiuresis of sodium and potassium. Protein has a delayed action, while fat refeeding aggravates the negative sodium balance. The sodium retaining action of carbohydrate requires a pre-existing metabolic setting induced by starvation. Bicarbonate supplementation during fasting does not alter the pattern of sodium excretion. The data suggest that the sodium retaining action of carbohydrate after brief starvation is not secondary to aldosterone, glucocorticosteroids or changes in catecholamine levels.

Practical methods for estimating the basic water requirement during oliguric renal failure.

SUMMARYA quantitative approach to the analysis of water requirements of anuric subjects is presented, showing the importance of cell water as an occult gain to the water balance during under‐nutrition.Methods of varying accuracy and complexity have been developed for prescribing the daily basic water requirement, and for determining the desirable daily weight loss. The usefulness of the methods has been tested by applying them to four “theoretically anuric” obese subjects, in whom the state of water balance was accurately measured during a period of 12 days' under‐nutrition.The daily basic water requirement for an average adult anuric is about 400 ml. if uræmia is mild, and less if uræmia is developing rapidly.